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Classifications

Mechanistic Nosology

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Inheritance

1

Autosomal recessive inheritance HP:0000007

All established Perrault syndrome genes act recessively; affected individuals carry two pathogenic alleles, most often as compound heterozygotes or, in consanguineous families, as homozygotes. Biallelic complete loss of function has not been observed for the mitochondrial translation genes, consistent with those genes being essential, so genotypes combine hypomorphic alleles with each other or with a null allele. Expressivity is markedly variable between and within families: hearing-loss severity, age of onset, degree of ovarian failure and the presence of neurological features differ even among siblings sharing a genotype. Sex modifies expression but not transmission: hearing loss occurs in both sexes, whereas the ovarian phenotype is confined to 46,XX individuals.

Autosomal recessive inheritance Penetrance: UNKNOWN Expressivity: VARIABLE

Show evidence (2 references)

PMID:34338890 SUPPORT Human Clinical

"Perrault syndrome is inherited as an autosomal recessive disorder characterized by bilateral mild to severe childhood sensorineural hearing loss with variable age of onset in both sexes and ovarian dysfunction in females who have a 46, XX karyotype."

States the autosomal recessive mode of inheritance and the sex-limited expression of the ovarian component in one sentence.

PMID:31827252 SUPPORT Human Clinical

"This lack of biallelic loss-of-function variants likely indicates that HARS2, along with the other Perrault syndrome associated genes, is essential and that complete loss-of-function would result in lethality."

Supports the constraint that surviving genotypes retain partial function, explaining why hypomorphic alleles dominate the mutational spectrum.

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Subtypes

9

Perrault syndrome 1 (HSD17B4) MONDO:0009300

HSD17B4 hgnc:5213 MONDO MONDO:0009300

Perrault syndrome caused by biallelic HSD17B4 variants. HSD17B4 encodes 17-beta-hydroxysteroid dehydrogenase type 4, also called D-bifunctional protein, a peroxisomal enzyme of fatty acid beta-oxidation. This was the first Perrault syndrome gene identified and is the principal peroxisomal exception among predominantly mitochondrial causes. Hypomorphic alleles give the Perrault phenotype whereas severe alleles give D-bifunctional protein deficiency, an allelic disorder curated separately; neurological features are characteristic of the HSD17B4 Perrault presentations reported to date.

Show evidence (1 reference)

PMID:20673864 SUPPORT Human Clinical

"Whole-exome sequencing of genomic DNA from one of these sisters revealed exactly one gene with two rare functional variants: HSD17B4, which encodes 17beta-hydroxysteroid dehydrogenase type 4 (HSD17B4), also known as D-bifunctional protein (DBP)."

Identifies HSD17B4 as the first Perrault syndrome gene.

Perrault syndrome 2 (HARS2) MONDO:0013972

HARS2 hgnc:4817 MONDO MONDO:0013972

Perrault syndrome caused by biallelic HARS2 variants. HARS2 encodes mitochondrial histidyl-tRNA synthetase, which charges mitochondrial tRNA-His. Hearing loss is often prelingual and progressive and can be the only manifestation in affected males and prepubertal girls, so HARS2 genotypes are a recognised cause of apparently nonsyndromic deafness.

Show evidence (1 reference)

PMID:21464306 SUPPORT Human Clinical

"In a nonconsanguineous family with five affected siblings, linkage analysis and genomic sequencing revealed the genetic basis of Perrault syndrome to be compound heterozygosity for mutations in the mitochondrial histidyl tRNA synthetase HARS2 at two highly conserved amino acids, L200V and V368L."

Establishes HARS2 as a Perrault syndrome gene.

Perrault syndrome 3 (CLPP) MONDO:0013588

CLPP hgnc:2084 MONDO MONDO:0013588

Perrault syndrome caused by biallelic CLPP variants. CLPP encodes the proteolytic subunit of the mitochondrial ATP-dependent CLPXP chambered protease, part of the mitochondrial unfolded protein response. Growth restriction, epilepsy and other neurological features are frequently reported, and CLPP is the gene for which male reproductive involvement is best supported by model-organism data.

Show evidence (1 reference)

PMID:23541340 SUPPORT Human Clinical

"By a combination of linkage analysis, homozygosity mapping, and exome sequencing in three families, we identified mutations in CLPP as the likely cause of this phenotype."

Establishes CLPP as a Perrault syndrome gene.

Perrault syndrome 4 (LARS2) MONDO:0014126

LARS2 hgnc:17095 MONDO MONDO:0014126

Perrault syndrome caused by biallelic LARS2 variants. LARS2 encodes mitochondrial leucyl-tRNA synthetase. LARS2 is the single most frequent cause in molecularly solved cohorts and has the broadest allelic spectrum, extending from isolated hearing loss with ovarian insufficiency to leukodystrophy and lethal infantile multisystem disease.

Show evidence (1 reference)

PMID:23541342 SUPPORT Human Clinical

"In two families affected by POF accompanied by hearing loss (together, these symptoms compose Perrault syndrome), exome sequencing revealed mutations in LARS2, encoding mitochondrial leucyl-tRNA synthetase"

Establishes LARS2 as a Perrault syndrome gene.

Perrault syndrome 5 (TWNK) MONDO:0014504

TWNK hgnc:1160 MONDO MONDO:0014504

Perrault syndrome caused by biallelic TWNK (formerly C10orf2) variants. TWNK encodes Twinkle, the mitochondrial DNA primase-helicase. Essentially all reported individuals have neurological involvement, making this subtype prototypically type II, and auditory neuropathy rather than pure cochlear loss has been documented. IMPORTANT NOSOLOGICAL NOTE — TWNK is pleiotropic: dominant missense variants cause progressive external ophthalmoplegia type 3, and a different set of recessive variants causes mitochondrial DNA depletion syndrome 7. Only the biallelic Perrault presentation belongs to this entry.

Show evidence (2 references)

PMID:25355836 SUPPORT Human Clinical

"Our study identifies Twinkle mutations as a cause of Perrault syndrome accompanied by neurologic features and expands the phenotypic spectrum of recessive disease caused by mutations in Twinkle."

Establishes recessive TWNK variants as a Perrault syndrome cause.

PMID:25355836 SUPPORT Human Clinical

"Twinkle is known also to harbor multiple mutations, nearly all missenses, leading to dominant progressive external ophthalmoplegia type 3 and to recessive mitochondrial DNA depletion syndrome 7, also known as infantile-onset spinocerebellar ataxia."

Documents the allelic disorders that must NOT be conflated with the recessive Perrault presentation, in particular dominant PEO type 3.

Perrault syndrome 6 (ERAL1) MONDO:0033047

ERAL1 hgnc:3424 MONDO MONDO:0033047

Perrault syndrome caused by biallelic ERAL1 variants. ERAL1 encodes a GTPase chaperone that binds mitochondrial 12S rRNA and is required for assembly of the small mitoribosomal subunit; patient fibroblasts show reduced assembled small subunit, reduced 12S rRNA and impaired mitochondrial respiration.

Show evidence (1 reference)

PMID:28449065 SUPPORT Human Clinical

"We excluded mutations in the known PS genes, but identified a single homozygous mutation in the ERAL1 gene (c.707A > T; p.Asn236Ile)."

Establishes ERAL1 as a Perrault syndrome gene.

Perrault syndrome 7 (DAP3) MONDO:0976232

DAP3 hgnc:2673 MONDO MONDO:0976232

Perrault syndrome caused by biallelic DAP3 variants. DAP3 encodes mitoribosomal small subunit protein 29 (MRPS29). Presentations span a Perrault-syndrome spectrum through to a severe childhood-onset neurometabolic phenotype with combined complex I and IV deficiency; this is the most recently designated numbered subtype.

Show evidence (1 reference)

PMID:39371131 SUPPORT Human Clinical

"Here, we describe five unrelated individuals with biallelic variants in the DAP3 nuclear gene encoding mitoribosomal small subunit 29 (MRPS29)"

Establishes DAP3 as a Perrault syndrome gene.

Type I (isolated Perrault syndrome)

The isolated clinical form: sensorineural hearing loss plus ovarian dysfunction in 46,XX individuals, without significant neurological disease. This is a descriptive clinical split, not a molecular one — the same gene can give type I in one individual and type II in another, and the boundary is increasingly blurred by multisystem presentations.

Show evidence (1 reference)

PMID:34338890 SUPPORT Human Clinical

"Since the initial clinical description of Perrault syndrome 70 years ago, the phenotype of some subjects may additionally involve developmental delay, intellectual deficit and other neurological disabilities, which can vary in severity in part dependent upon the genetic variants and the gene involved."

Establishes that neurological involvement is present in only a subset, which is the basis for separating the isolated form from the neurological form.

Type II (Perrault syndrome with neurological features)

The neurological clinical form: the cardinal hearing and ovarian features plus progressive cerebellar ataxia, peripheral axonal neuropathy, hyporeflexia, abnormal eye movements, developmental delay, intellectual disability and, in some individuals, cerebral white-matter abnormality or leukodystrophy. TWNK and HSD17B4 genotypes are almost always type II; severe LARS2 alleles can add leukodystrophy.

Show evidence (1 reference)

PMID:25355836 SUPPORT Human Clinical

"To identify the genetic cause in 2 families of progressive ataxia, axonal neuropathy, hyporeflexia, and abnormal eye movements, accompanied by progressive hearing loss and ovarian dysgenesis, with a clinical diagnosis of Perrault syndrome."

Enumerates the neurological features that define the type II clinical form alongside the cardinal features.

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Pathophysiology

13

Biallelic Loss of Mitochondrial Gene-Expression and Proteostasis Factors

The initiating lesion is inheritance of two hypomorphic alleles, or one hypomorphic plus one null allele, in a nuclear gene whose product supports mitochondrial gene expression or protein quality control. Because these genes are essential, complete biallelic loss of function has not been observed in surviving individuals; residual activity determines whether the phenotype is organ-selective Perrault syndrome or a severe infantile multisystem mitochondrial disease. Fifteen genes have now been implicated, converging on a small number of mitochondrial processes plus two metabolic exceptions.

LARS2 hgnc:17095 HARS2 hgnc:4817 CLPP hgnc:2084 TWNK hgnc:1160 HSD17B4 hgnc:5213 ERAL1 hgnc:3424 DAP3 hgnc:2673 PRORP hgnc:19958 RMND1 hgnc:21176 GGPS1 hgnc:4249 MRPS7 hgnc:14499 PEX6 hgnc:8859

Downstream

Impaired Mitochondrial Translation and RNA Maturation Loss of aminoacyl-tRNA synthetase, mitoribosome-assembly, tRNA-processing or translation-support function directly reduces mitochondrial protein synthesis.

Mitochondrial Matrix Proteostasis Failure Loss of the CLPP proteolytic subunit removes the degradative arm of mitochondrial protein quality control.

Mitochondrial DNA Maintenance Failure Loss of Twinkle helicase or TFAM function impairs replication and packaging of the mitochondrial genome.

Peroxisomal Fatty Acid Beta-Oxidation Failure HSD17B4 and PEX6 lesions act through peroxisomal fatty acid beta-oxidation rather than through mitochondrial gene expression.

Isoprenoid Synthesis and Protein Prenylation Failure GGPS1 lesions act through the mevalonate/isoprenoid pathway and loss of protein prenylation, a mechanism distinct from both mitochondrial gene expression and peroxisomal beta-oxidation.

Show evidence (1 reference)

PMID:42283975 SUPPORT Human Clinical

"highlighting mutations in fifteen principal genes: HSD17B4, HARS2, CLPP, LARS2, TWNK, ERAL1, RMND1, DAP3, PRORP, MRPL50, MRPL49, MRPS7, PEX6, GGPS1, and TFAM. Each of these genes plays a critical role either in mitochondrial function or peroxisomal processes, central to cellular energy..."

Enumerates the causal gene set and states that all converge on mitochondrial or peroxisomal function.

Impaired Mitochondrial Translation and RNA Maturation

The dominant mechanistic axis. Mitochondrial aminoacyl-tRNA synthetases HARS2 and LARS2 charge mitochondrial tRNA-His and tRNA-Leu; PRORP is the metallonuclease subunit of mitochondrial RNase P and performs 5' end processing of precursor tRNAs; ERAL1, DAP3/MRPS29 and MRPS7 build the small mitoribosomal subunit; RMND1 tethers mitoribosomes near sites of transcript maturation. Reduced activity in any of these steps lowers the rate or fidelity of synthesis of the thirteen mtDNA-encoded oxidative phosphorylation subunits.

mitochondrial translation GO:0032543 ↓ DECREASED tRNA aminoacylation for mitochondrial protein translation GO:0070127 ↓ DECREASED mitochondrial tRNA processing GO:0090646 ↓ DECREASED mitochondrial small ribosomal subunit assembly GO:0180026 ↓ DECREASED

mitochondrial matrix GO:0005759

Downstream

Combined Oxidative Phosphorylation Deficiency and Bioenergetic Stress Reduced synthesis of mtDNA-encoded subunits limits assembly of respiratory chain complexes I, III, IV and V.

Show evidence (3 references)

PMID:23541342 SUPPORT Human Clinical

"After HARS2, LARS2 is the second gene encoding mitochondrial tRNA synthetase to be found to harbor mutations leading to Perrault syndrome, further supporting a critical role for mitochondria in the maintenance of ovarian function and hearing."

Establishes mitochondrial tRNA charging, and therefore mitochondrial translation, as the shared mechanism of the two synthetase subtypes.

PMID:34715011 SUPPORT In Vitro

"Fibroblasts from affected individuals in two families demonstrated decreased steady state levels of PRORP, an accumulation of unprocessed mitochondrial transcripts, and decreased steady state levels of mitochondrial-encoded proteins, which were rescued by introduction of the wild-type PRORP cDNA."

Direct patient-cell evidence that a Perrault gene defect blocks mitochondrial RNA maturation and lowers mitochondrial protein output, with rescue confirming causality.

PMID:28449065 SUPPORT In Vitro

"Complexome profiling of the cells showed an overall decrease in the levels of assembled small ribosomal subunit, indicating that the ERAL1 variant affects mitochondrial ribosome assembly."

Patient-fibroblast evidence for the mitoribosome-assembly arm of the same translational axis.

Mitochondrial Matrix Proteostasis Failure

CLPP encodes the peptidase subunit of the CLPXP complex, the principal ATP-dependent protease of the mitochondrial matrix and an effector arm of the mitochondrial unfolded protein response. Perrault-associated substitutions cluster in a short region and are predicted to distort the barrel chamber that captures unfolded substrates. Loss of proteolysis allows damaged and unassembled matrix proteins to accumulate, and in Clpp-null mice the other Perrault proteins ERAL1, Twinkle and HARS2 themselves accumulate, indicating that the proteostatic and translational arms of the disease are mechanistically coupled rather than independent.

mitochondrial unfolded protein response GO:0034514 ⚠ ABNORMAL

mitochondrial matrix GO:0005759

Downstream

Combined Oxidative Phosphorylation Deficiency and Bioenergetic Stress Accumulation of damaged matrix proteins compromises respiratory chain integrity and mitochondrial function.

Show evidence (2 references)

PMID:23541340 SUPPORT Human Clinical

"Together with the previous identification of mutations in HARS2, encoding mitochondrial histidyl-tRNA synthetase, mutations in CLPP expose dysfunction of mitochondrial protein homeostasis as a cause of Perrault syndrome."

States that mitochondrial proteostasis, distinct from translation itself, is a causal mechanism of the syndrome.

PMID:23541340 SUPPORT Computational

"Crystal-structure modeling suggests that both substitutions would alter the structure of the CLPP barrel chamber that captures unfolded proteins and exposes them to proteolysis."

Structural modelling linking the specific substitutions to loss of substrate capture, i.e. loss of function of the protease.

Mitochondrial DNA Maintenance Failure

TWNK encodes Twinkle, the replicative primase-helicase that unwinds mitochondrial DNA at the replication fork, and TFAM packages and transcribes the mitochondrial genome. Biallelic hypomorphic alleles impair mtDNA replication and reduce mtDNA copy number in the tissues that depend most heavily on oxidative metabolism, indirectly limiting the template available for mitochondrial gene expression. This arm is the most reliably neurological, with essentially all reported TWNK Perrault individuals manifesting ataxia or neuropathy.

TWNK hgnc:1160 TFAM hgnc:11741

mitochondrial DNA replication GO:0006264 ↓ DECREASED

Downstream

Combined Oxidative Phosphorylation Deficiency and Bioenergetic Stress Reduced mtDNA template limits expression of the thirteen mtDNA-encoded respiratory chain subunits.

Show evidence (1 reference)

PMID:25355836 SUPPORT Human Clinical

"C10orf2 encodes Twinkle, a primase-helicase essential for replication of mitochondrial DNA."

Identifies the molecular function whose loss constitutes this mechanistic arm.

Peroxisomal Fatty Acid Beta-Oxidation Failure

The first of two metabolic exceptions that reach the Perrault endpoint without acting on mitochondrial gene expression. HSD17B4 encodes D-bifunctional protein, a core enzyme of peroxisomal fatty acid beta-oxidation, and PEX6 is a peroxisome biogenesis factor whose loss impairs import of the matrix enzymes that carry out the same pathway. Hypomorphic genotypes leave enough residual peroxisomal flux for survival beyond infancy, allowing the cochlear and ovarian phenotype to declare itself; severe genotypes instead give D-bifunctional protein deficiency or Zellweger-spectrum disease.

HSD17B4 hgnc:5213 PEX6 hgnc:8859

fatty acid beta-oxidation using acyl-CoA oxidase GO:0033540 ↓ DECREASED

peroxisome GO:0005777

Downstream

Cochlear Hair Cell Mitochondrial Injury and Loss Peroxisomal lipid-handling failure injures the metabolically active cochlear sensory epithelium.

Ovarian Germ Cell Depletion and Follicular Failure Impaired peroxisomal lipid and steroid handling compromises ovarian somatic and germ cell function.

Show evidence (2 references)

PMID:32399598 SUPPORT Human Clinical

"For the first time, we show that pathogenic variants in PEX6 can present clinically as Perrault syndrome. PEX6 encodes a peroxisomal biogenesis factor, and we demonstrate evidence of peroxisomal dysfunction in patient serum."

Establishes the peroxisomal arm as a genuine molecular cause of the Perrault phenotype, with biochemical confirmation of peroxisomal dysfunction.

PMID:20673864 SUPPORT Human Clinical

"HSD17B4/DBP is a multifunctional peroxisomal enzyme involved in fatty acid beta-oxidation and steroid metabolism."

Identifies the peroxisomal beta-oxidation function whose loss constitutes this arm.

Isoprenoid Synthesis and Protein Prenylation Failure

The second metabolic exception, mechanistically unrelated to the peroxisomal arm. GGPS1 encodes geranylgeranyl diphosphate synthase in the mevalonate/isoprenoid pathway; its product geranylgeranyl pyrophosphate is the lipid anchor required to prenylate small GTPases and is separately required for murine folliculogenesis. Loss of prenylation therefore produces a distinctive triad of muscular dystrophy with sensorineural hearing loss and ovarian insufficiency, the muscle component being unique to this arm.

GGPS1 hgnc:4249

protein prenylation GO:0018342 ↓ DECREASED

Downstream

Cochlear Hair Cell Mitochondrial Injury and Loss Loss of prenylation-dependent signalling injures the cochlear sensory epithelium, producing congenital hearing loss in nearly all GGPS1 cases.

Ovarian Germ Cell Depletion and Follicular Failure Geranylgeranyl pyrophosphate is required for folliculogenesis, so its depletion causes ovarian insufficiency.

Proximal Muscle Weakness Impaired prenylation-dependent sarcolemmal membrane repair produces the dystrophic muscle phenotype unique to the GGPS1 arm.

Show evidence (2 references)

PMID:32403198 SUPPORT Human Clinical

"GGPS1 encodes geranylgeranyl diphosphate synthase in the mevalonate/isoprenoid pathway, which catalyzes the synthesis of geranylgeranyl pyrophosphate, the lipid precursor of geranylgeranylated proteins including small guanosine triphosphatases."

Establishes the isoprenoid arm and the specific biochemical step it disrupts.

PMID:32403198 SUPPORT In Vitro

"There was delayed membrane healing after laser injury in patient-derived myogenic cells,"

Functional evidence for the prenylation-dependent membrane-repair defect that gives this arm its muscle phenotype.

Combined Oxidative Phosphorylation Deficiency and Bioenergetic Stress

The convergence point of the mitochondrial arms. Reduced synthesis, maturation or quality control of mtDNA-encoded subunits produces a combined respiratory chain deficiency, most consistently affecting complexes I and IV, with reduced cellular respiration, elevated reactive oxygen species and proteostatic stress. Cell types with high and sustained oxidative demand and little regenerative capacity — cochlear hair cells, oocytes and long peripheral and cerebellar neurons — are selectively vulnerable, which is why a defect in a ubiquitously expressed housekeeping gene produces an organ-selective syndrome.

oxidative phosphorylation GO:0006119 ↓ DECREASED

mitochondrion GO:0005739

Downstream

Cochlear Hair Cell Mitochondrial Injury and Loss Cochlear hair cells have exceptionally high oxidative demand and are postmitotic, so they decompensate first.

Ovarian Germ Cell Depletion and Follicular Failure Oocytes carry the largest mitochondrial complement of any human cell and the non-renewable follicle pool cannot be replaced once depleted.

Neuronal and Axonal Degeneration Long peripheral axons and cerebellar circuits fail when oxidative capacity falls below their sustained demand, producing the type II phenotype.

Chronic Kidney Disease Renal tubular epithelium is oxidative-phosphorylation dependent; renal involvement is characteristic of the RMND1 arm.

Show evidence (2 references)

PMID:28449065 SUPPORT In Vitro

"At the physiological level, mitochondrial respiration was markedly decreased in PS fibroblasts, confirming disturbed mitochondrial function."

Direct patient-cell measurement of the bioenergetic deficit downstream of a Perrault gene defect.

PMID:39371131 SUPPORT In Vitro

"Assessment of respiratory chain function and proteomic profiling of fibroblasts from affected individuals demonstrated reduced MRPS29 protein levels, and consequently decreased levels of additional protein components of the mitoribosomal small subunit, associated with a combined complex I and IV..."

Demonstrates that a mitoribosomal Perrault lesion produces a combined complex I and IV deficiency.

Cochlear Hair Cell Mitochondrial Injury and Loss

Cochlear inner and outer hair cells accumulate morphologically abnormal mitochondria, generate excess reactive oxygen species and activate the mitochondrial apoptotic pathway. Synaptic function deteriorates before frank cell loss: in conditional Hars2-knockout mice, inner hair cells show reduced calcium influx and compromised sustained exocytosis at postnatal day 30, weeks before hair cell death, and outer hair cells ultimately suffer the greater loss. In some genotypes, notably TWNK, the deficit is retrocochlear or synaptic rather than purely sensory, presenting as auditory neuropathy with preserved otoacoustic emissions but absent auditory brainstem responses.

cochlear inner hair cell CL:0000589 cochlear outer hair cell CL:0000601

sensory perception of sound GO:0007605 ↓ DECREASED apoptotic process GO:0006915 ↑ INCREASED

cochlea UBERON:0001844

Downstream

Sensorineural Hearing Loss Loss of hair cell transduction and synaptic output produces the cardinal audiological outcome.

Auditory Neuropathy Pattern Where the lesion is at the inner hair cell synapse or cochlear nerve rather than at the outer hair cell, the audiological signature is auditory neuropathy with preserved otoacoustic emissions.

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PMID:34975414 SUPPORT Model Organism

"Taken together, our results suggest that conditional knockout of Hars2 in mouse cochlear hair cells leads to accumulating mitochondrial dysfunction and ROS stress, triggers progressive hearing loss highlighted by hair cell synaptopathy and apoptosis, and is differentially perceived by inner and..."

Mouse conditional knockout of a Perrault gene establishes hair-cell mitochondrial dysfunction and apoptosis as the cochlear mechanism.

PMID:34975414 SUPPORT Model Organism

"Targeted knockout of Hars2 in mouse hair cells resulted in delayed onset (P30), rapidly progressive hearing loss similar to the PRLTS2 hearing phenotype."

Shows the model recapitulates the delayed-onset, progressive character of human PRLTS2 hearing loss.

Ovarian Germ Cell Depletion and Follicular Failure

Oogonia, oocytes and their granulosa support cells fail to survive or to sustain folliculogenesis. The severity of the germ cell deficit sets the clinical severity: near-complete prenatal or early postnatal germ cell loss yields streak or absent ovaries and primary amenorrhoea, whereas partial depletion leaves a reduced follicle pool that is exhausted prematurely and presents as secondary amenorrhoea after normal menarche. Because the human follicle pool is fixed before birth and not renewed, the loss is irreversible. Cross-species data support the requirement: RNAi knockdown of the C. elegans ERAL1 orthologue almost abolishes egg production.

oocyte CL:0000023 granulosa cell CL:0000501

ovarian follicle development GO:0001541 ↓ DECREASED oocyte development GO:0048599 ↓ DECREASED

ovary UBERON:0000992

Downstream

Sex-Limited Expression of the Gonadal Phenotype The germ cell deficit becomes a clinically recognised gonadal phenotype only in individuals with a 46,XX karyotype.

Ovarian Dysgenesis with Streak Gonads Near-complete developmental germ cell loss leaves dysplastic, streak or absent ovaries.

Show evidence (2 references)

PMID:28449065 SUPPORT Model Organism

"Finally, knockdown of the C. elegans ERAL1 homologue E02H1.2 almost completely blocked egg production in worms, mimicking the compromised fertility in PS-affected women."

Cross-species evidence that the mitoribosomal defect impairs gametogenesis, supporting a germ-cell-autonomous mechanism.

PMID:21464306 SUPPORT Model Organism

"In Caenorhabditis elegans, reduced expression by RNAi of the single essential histydyl tRNA synthetase hars-1 severely compromised fertility."

Independent cross-species evidence that reduced mitochondrial tRNA charging compromises fertility.

Sex-Limited Expression of the Gonadal Phenotype

The defining and most distinctive feature of the disorder. The same biallelic genotype produces hearing loss in both sexes but a clinically manifest gonadal phenotype essentially only in 46,XX individuals. The mechanistic basis is the asymmetry of mammalian gametogenesis: the female germ cell pool is established prenatally, is finite and is not renewed, so a chronic bioenergetic deficit in a non-renewable oocyte population produces irreversible follicular exhaustion and hypergonadotropic hypogonadism at or shortly after puberty. Male germ cells, by contrast, are continuously regenerated from spermatogonial stem cells, so 46,XY individuals with the same genotype usually have normal gonadal function and normal fertility, though azoospermia and undervirilisation are occasionally described and CLPP-null mice have a clear meiotic arrest phenotype. This asymmetry is not a difference in inheritance — transmission is ordinary autosomal recessive — but it has a major ascertainment consequence: affected males and prepubertal girls present with what looks like isolated nonsyndromic deafness, so Perrault syndrome is systematically under-recognised in males and diagnosed late in girls.

oocyte CL:0000023 spermatocyte CL:0000017

Downstream

Hypergonadotropic Ovarian Failure In 46,XX individuals the exhausted follicle pool cannot generate adequate oestradiol or inhibin, releasing pituitary gonadotropin secretion from negative feedback.

Male Infertility In the minority of 46,XY individuals in whom the germ line is affected, the same energetic deficit impairs spermatogenesis; this remains an uncommon, genotype-restricted outcome.

Show evidence (3 references)

PMID:34338890 SUPPORT Human Clinical

"Perrault syndrome is inherited as an autosomal recessive disorder characterized by bilateral mild to severe childhood sensorineural hearing loss with variable age of onset in both sexes and ovarian dysfunction in females who have a 46, XX karyotype."

States the sex-limited expression explicitly: hearing loss in both sexes, ovarian dysfunction restricted to a 46,XX karyotype.

PMID:31827252 SUPPORT Human Clinical

"All affected individuals are either male or prepubertal and as such would not present with POI, a cardinal feature of Perrault syndrome."

Directly demonstrates the ascertainment consequence: individuals with a Perrault genotype who are male or prepubertal present as nonsyndromic hearing loss.

PMID:20673864 SUPPORT Human Clinical

"Perrault syndrome is a recessive disorder characterized by ovarian dysgenesis in females, sensorineural deafness in both males and females, and in some patients, neurological manifestations."

Independent statement of the sex-limited gonadal component alongside sex-independent deafness.

Neuronal and Axonal Degeneration

In the type II form, the bioenergetic deficit additionally compromises neurons with the longest axons and the highest sustained metabolic demand. Cerebellar Purkinje circuits and long peripheral sensory and motor axons degenerate, producing progressive ataxia, distal axonal neuropathy, hyporeflexia and abnormal eye movements; more severe alleles, particularly of LARS2 and PRORP, additionally produce cerebral white-matter abnormality or frank leukodystrophy, and developmental delay or intellectual disability when onset is early.

Purkinje cell CL:0000121

cerebellum UBERON:0002037

Downstream

Cerebellar Ataxia Cerebellar degeneration produces the progressive ataxia of type II disease.

Peripheral Axonal Neuropathy Distal degeneration of long peripheral axons produces a length-dependent neuropathy.

Hyporeflexia Loss of afferent and efferent conduction in degenerating peripheral axons abolishes deep tendon reflexes.

Intellectual Disability Early and severe central involvement impairs cognitive development.

Global Developmental Delay Early-onset central nervous system involvement delays motor, language and cognitive milestones.

Cerebral White Matter Abnormality Oligodendrocyte and axonal energy failure produces white-matter signal change, reaching frank leukodystrophy with severe alleles.

Abnormal Eye Movements Degeneration of cerebellar and brainstem oculomotor circuits produces the abnormal eye movements reported alongside ataxia in type II disease.

Show evidence (2 references)

PMID:31827252 SUPPORT Human Clinical

"In some cases of Perrault syndrome additional neurological features, including peripheral neuropathy, cerebellar ataxia, and intellectual disability have also been identified"

Enumerates the neurological features that constitute the type II arm.

PMID:34715011 SUPPORT Human Clinical

"Affected individuals presented with variable phenotypes comprising sensorineural hearing loss, primary ovarian insufficiency, developmental delay, and brain white matter changes."

Documents developmental delay and cerebral white-matter change as part of the neurological arm.

Sensorineural Hearing Loss

The sex-independent cardinal manifestation. Loss is bilateral and ranges from profound with prelingual onset to moderate with early-childhood or even adult onset; it is frequently progressive. Middle-ear function is normal.

Downstream

Bilateral Sensorineural Hearing Impairment The audiological outcome is recorded clinically as bilateral sensorineural hearing impairment.

Progressive Hearing Loss Continuing hair cell attrition drives progression of the threshold elevation over time.

Show evidence (1 reference)

PMID:42283975 SUPPORT Human Clinical

"Perrault syndrome is a genetically and clinically diverse autosomal recessive disorder characterized by sensorineural hearing loss in both sexes and primary ovarian insufficiency in females."

Establishes hearing loss as a defining, sex-independent outcome.

Hypergonadotropic Ovarian Failure

The 46,XX-restricted cardinal manifestation. Loss of ovarian follicular function removes oestradiol and inhibin feedback, so pituitary FSH and LH rise, producing hypergonadotropic hypogonadism. The clinical presentation depends on how much ovarian tissue was ever functional: absent spontaneous puberty with primary amenorrhoea and streak or absent ovaries at the severe end, or normal menarche followed by irregular menses and secondary amenorrhoea before age 40 at the milder end. Consequences beyond infertility are those of untreated hypo-oestrogenism — reduced bone density and osteoporosis, and adverse cardiovascular and urogenital outcomes.

Downstream

Premature Ovarian Insufficiency Loss of ovarian function before age 40 is the clinical definition of this outcome.

Hypergonadotropic Hypogonadism Loss of ovarian steroid and inhibin feedback raises pituitary gonadotropins.

Primary Amenorrhea When ovarian function was never established, menarche does not occur.

Secondary Amenorrhea When a reduced follicle pool is exhausted after menarche, menses cease.

Female Infertility Follicular depletion removes the oocytes required for conception.

Elevated Serum Follicle-Stimulating Hormone Release of the pituitary from ovarian negative feedback raises circulating FSH, the biochemical marker of the outcome.

Osteoporosis Prolonged oestrogen deficiency accelerates bone resorption and lowers bone mineral density, a preventable complication of untreated ovarian failure.

Show evidence (1 reference)

PMID:32767731 SUPPORT Human Clinical

"The literature review showed that the phenotype for PRLTS4 varies widely, but the sensorineural hearing loss, increased gonadotropin levels, and amenorrhea occurred frequently."

Confirms elevated gonadotropins and amenorrhoea as the recurrent endocrine outcome.

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Pathograph

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Phenotypes

20

Ear 1

Bilateral Sensorineural Hearing Impairment VERY_FREQUENT HP:0000407

Show evidence (1 reference)

PMID:42283975 SUPPORT Human Clinical

"Perrault syndrome is a genetically and clinically diverse autosomal recessive disorder characterized by sensorineural hearing loss in both sexes and primary ovarian insufficiency in females."

Sensorineural hearing loss is definitional and therefore present in essentially all affected individuals, supporting VERY_FREQUENT.

Context-specific annotations (1)

MALE

Hearing loss is fully expressed in 46,XY individuals, who typically have no gonadal phenotype and may therefore be classified as having nonsyndromic deafness.

Show evidence (1 reference)

PMID:34338890 SUPPORT Human Clinical

"Perrault syndrome is inherited as an autosomal recessive disorder characterized by bilateral mild to severe childhood sensorineural hearing loss with variable age of onset in both sexes and ovarian dysfunction in females who have a 46, XX karyotype."

Confirms hearing loss occurs in both sexes.

Endocrine 1

Hypergonadotropic Hypogonadism HP:0000815

Show evidence (1 reference)

PMID:32767731 SUPPORT Human Clinical

"The literature review showed that the phenotype for PRLTS4 varies widely, but the sensorineural hearing loss, increased gonadotropin levels, and amenorrhea occurred frequently."

Documents elevated gonadotropins accompanying amenorrhoea.

Eye 1

Abnormal Eye Movements Abnormality of eye movement HP:0000496

Show evidence (1 reference)

PMID:25355836 SUPPORT Human Clinical

"To identify the genetic cause in 2 families of progressive ataxia, axonal neuropathy, hyporeflexia, and abnormal eye movements, accompanied by progressive hearing loss and ovarian dysgenesis, with a clinical diagnosis of Perrault syndrome."

Lists abnormal eye movements among the neurological features of clinically diagnosed Perrault syndrome.

Genitourinary 6

Premature Ovarian Insufficiency VERY_FREQUENT HP:0008209

Show evidence (1 reference)

PMID:42283975 SUPPORT Human Clinical

"Perrault syndrome is a genetically and clinically diverse autosomal recessive disorder characterized by sensorineural hearing loss in both sexes and primary ovarian insufficiency in females."

Primary ovarian insufficiency is definitional in 46,XX individuals, supporting VERY_FREQUENT within that stratum.

Context-specific annotations (2)

FEMALE VERY_FREQUENT

Restricted to individuals with a 46,XX karyotype; essentially universal in postpubertal 46,XX individuals with a Perrault genotype.

Show evidence (1 reference)

PMID:34338890 SUPPORT Human Clinical

"Perrault syndrome is inherited as an autosomal recessive disorder characterized by bilateral mild to severe childhood sensorineural hearing loss with variable age of onset in both sexes and ovarian dysfunction in females who have a 46, XX karyotype."

Restricts the ovarian phenotype to the 46,XX karyotype stratum.

MALE

Not expressed. 46,XY individuals with the same genotype have hearing loss with generally preserved gonadal function, which is why they present as apparently nonsyndromic deafness.

Show evidence (1 reference)

PMID:31827252 SUPPORT Human Clinical

"All affected individuals are either male or prepubertal and as such would not present with POI, a cardinal feature of Perrault syndrome."

Confirms that male carriers of a Perrault genotype do not manifest the ovarian phenotype.

Primary Amenorrhea HP:0000786

Show evidence (1 reference)

PMID:32911714 SUPPORT Human Clinical

"Evaluation for primary amenorrhea and delayed pubertal development at the age of 18 revealed gonadal dysgenesis with a normal female karyotype 46,XX."

Documents primary amenorrhoea with gonadal dysgenesis and a normal 46,XX karyotype in a genetically confirmed individual.

Secondary Amenorrhea HP:0000869

Show evidence (1 reference)

PMID:31827252 SUPPORT Human Clinical

"They have a similar phenotype of profound SNHL with onset before 3 years of age and secondary amenorrhea presenting at 25 and 26 years of age, respectively."

Documents secondary amenorrhoea as the ovarian presentation in two HARS2-related individuals.

Female Infertility HP:0008222

Show evidence (1 reference)

PMID:32911714 SUPPORT Human Clinical

"Hypergonadotropic hypogonadism and small ovaries and uterus were recognized. Infertility was diagnosed, and hormone replacement therapy was introduced at the age of 28."

Documents infertility as a consequence of the ovarian phenotype in a genetically confirmed individual.

Chronic Kidney Disease HP:0012622

Show evidence (1 reference)

PMID:32911714 SUPPORT Human Clinical

"We performed a thorough clinical investigation and applied a targeted multigene hearing loss panel to reveal the cause of hearing loss, ovarian dysfunction (two cardinal features of Perrault syndrome) and chronic kidney disease in two adult female siblings."

Documents chronic kidney disease alongside the cardinal features in RMND1-related disease.

Male Infertility HP:0003251

Male infertility is a real but genotype-restricted and uncommon finding. A human CLPP case documents non-obstructive azoospermia, while CLPP-null mouse data provide mechanistic evidence for meiotic arrest. Do not generalise male infertility to Perrault syndrome as a whole.

Show evidence (2 references)

PMID:36611846 SUPPORT Human Clinical

"Non-obstructive azoospermia (NOS, the complete absence of sperm from the ejaculate, due to a failure in spermatogenesis, leading to complete infertility) was observed so far in one of the few male individuals with a biallelic missense mutation in the gene encoding the mitochondrial matrix peptidase CLPP"

Documents a human CLPP-associated case of non-obstructive azoospermia, establishing direct clinical support while preserving its rarity and genotype restriction.

PMID:36611846 SUPPORT Model Organism

"No meiotic M-phase cells were detected. Proteome profiles identified strong deficits of proteins involved in male meiotic prophase (HSPA2, SHCBP1L, DMRT7, and HSF5), versus an accumulation of AURKAIP1."

Documents late meiotic arrest in CLPP-null mouse testis, providing mechanistic model evidence for the genotype-restricted male infertility phenotype.

Musculoskeletal 2

Osteoporosis HP:0000939

Show evidence (1 reference)

PMID:32911714 SUPPORT Human Clinical

"Vitamin B12 deficiency anemia and osteoporosis were diagnosed at the age of 26."

Documents early-onset osteoporosis in a genetically confirmed individual with Perrault syndrome and ovarian insufficiency.

Proximal Muscle Weakness HP:0003701

Show evidence (1 reference)

PMID:32403198 SUPPORT Human Clinical

"In addition to proximal weakness, all but one patient presented with congenital sensorineural hearing loss, and all postpubertal females had primary ovarian insufficiency."

Documents proximal weakness together with the cardinal Perrault features in the GGPS1 cohort.

Nervous System 4

Cerebellar Ataxia HP:0001251

Course: PROGRESSIVE

Show evidence (1 reference)

PMID:31827252 SUPPORT Human Clinical

"In some cases of Perrault syndrome additional neurological features, including peripheral neuropathy, cerebellar ataxia, and intellectual disability have also been identified"

Documents cerebellar ataxia as a recognised feature.

Intellectual Disability HP:0001249

Show evidence (1 reference)

PMID:34338890 SUPPORT Human Clinical

"the phenotype of some subjects may additionally involve developmental delay, intellectual deficit and other neurological disabilities, which can vary in severity in part dependent upon the genetic variants and the gene involved"

Documents intellectual deficit in a subset, with genotype-dependent severity.

Global Developmental Delay HP:0001263

Show evidence (1 reference)

PMID:34715011 SUPPORT Human Clinical

"Affected individuals presented with variable phenotypes comprising sensorineural hearing loss, primary ovarian insufficiency, developmental delay, and brain white matter changes."

Documents developmental delay in PRORP-related Perrault syndrome.

Cerebral White Matter Abnormality Abnormal cerebral white matter morphology HP:0002500

Show evidence (1 reference)

PMID:34715011 SUPPORT Human Clinical

"Affected individuals presented with variable phenotypes comprising sensorineural hearing loss, primary ovarian insufficiency, developmental delay, and brain white matter changes."

Documents brain white matter changes as part of the phenotype.

Other 5

Progressive Hearing Loss Progressive sensorineural hearing impairment HP:0000408

Course: PROGRESSIVE

Show evidence (1 reference)

PMID:31827252 SUPPORT Human Clinical

"Here, we report the variant HARS2 c.1439G>A p.(Arg480His) in three unrelated families with prelingual onset, bilateral symmetric progressive SNHL."

Documents progressive bilateral sensorineural hearing loss.

Auditory Neuropathy Pattern Abnormal auditory evoked potentials HP:0006958

Show evidence (1 reference)

PMID:39340975 SUPPORT Human Clinical

"Maximum speech intelligibility score was 95 % with normal otoacoustic emission. However, no auditory brainstem responses were observed, leading to the diagnosis of auditory neuropathy."

Documents the preserved-OAE, absent-ABR auditory neuropathy pattern in TWNK-related Perrault syndrome.

Ovarian Dysgenesis with Streak Gonads Streak ovary HP:0010464

Show evidence (1 reference)

PMID:31827252 SUPPORT Human Clinical

"Ovarian dysgenesis, with amenorrhea and streak gonads"

Records streak gonads with ovarian dysgenesis in a tabulated Perrault syndrome case.

Peripheral Axonal Neuropathy HP:0003477

Show evidence (1 reference)

PMID:25355836 SUPPORT Human Clinical

"To identify the genetic cause in 2 families of progressive ataxia, axonal neuropathy, hyporeflexia, and abnormal eye movements, accompanied by progressive hearing loss and ovarian dysgenesis, with a clinical diagnosis of Perrault syndrome."

Documents axonal neuropathy in clinically diagnosed Perrault syndrome.

Hyporeflexia HP:0001265

Show evidence (1 reference)

PMID:25355836 SUPPORT Human Clinical

"To identify the genetic cause in 2 families of progressive ataxia, axonal neuropathy, hyporeflexia, and abnormal eye movements, accompanied by progressive hearing loss and ovarian dysgenesis, with a clinical diagnosis of Perrault syndrome."

Documents hyporeflexia in the type II presentation.

🧬

Genetic Associations

13

LARS2

Gene: LARS2 hgnc:17095 relationship_type: CAUSATIVE

Show evidence (2 references)

PMID:23541342 SUPPORT Human Clinical

"In two families affected by POF accompanied by hearing loss (together, these symptoms compose Perrault syndrome), exome sequencing revealed mutations in LARS2, encoding mitochondrial leucyl-tRNA synthetase"

Establishes LARS2 causality.

PMID:23541342 SUPPORT In Vitro

"Yeast complementation indicated that LARS2 c.1077delT is nonfunctional and that LARS2 p.Thr522Asn is partially functional."

Functional evidence that pathogenic alleles are hypomorphic or null, supporting a loss-of-function mechanism.

CLPP

Gene: CLPP hgnc:2084 relationship_type: CAUSATIVE

Show evidence (1 reference)

PMID:23541340 SUPPORT Human Clinical

"In each family, affected individuals were homozygous for a different pathogenic CLPP allele: c.433A>C (p.Thr145Pro), c.440G>C (p.Cys147Ser), or an experimentally demonstrated splice-donor-site mutation, c.270+4A>G."

Establishes CLPP causality with three independent homozygous alleles.

HARS2

Gene: HARS2 hgnc:4817 relationship_type: CAUSATIVE

Show evidence (1 reference)

PMID:21464306 SUPPORT In Vitro

"Aminoacylation activity of HARS2 p.V368L and HARS2 p.L200V was reduced and the deletion mutant was not stably expressed in mammalian mitochondria."

Functional evidence that the pathogenic alleles reduce mitochondrial tRNA charging.

HSD17B4

Gene: HSD17B4 hgnc:5213 relationship_type: CAUSATIVE

Show evidence (1 reference)

PMID:20673864 SUPPORT Human Clinical

"These results indicate that Perrault syndrome and DBP deficiency overlap clinically; that Perrault syndrome is genetically heterogeneous; that DBP deficiency may be underdiagnosed; and that whole-exome sequencing can reveal critical genes in small, nonconsanguineous families."

Establishes HSD17B4 causality and the allelic relationship with D-bifunctional protein deficiency.

TWNK

Gene: TWNK hgnc:1160 relationship_type: CAUSATIVE

Show evidence (2 references)

PMID:25355836 SUPPORT Human Clinical

"In family 1, affected individuals were compound heterozygous for chromosome 10 open reading frame 2 (C10orf2) p.Arg391His and p.Asn585Ser."

Documents biallelic (compound heterozygous) TWNK genotypes in Perrault syndrome, establishing the recessive mode for this phenotype.

PMID:25355836 SUPPORT Human Clinical

"The phenotypic heterogeneity of conditions caused by Twinkle mutations and the genetic heterogeneity of Perrault syndrome call for genomic definition of these disorders."

Supports the need to keep the TWNK-associated phenotypes nosologically distinct rather than merged.

PRORP

Gene: PRORP hgnc:19958 relationship_type: CAUSATIVE

Show evidence (1 reference)

PMID:34715011 SUPPORT Human Clinical

"We report four unrelated families with multisystem disease associated with bi-allelic variants in PRORP, the metallonuclease subunit of mt-RNase P."

Establishes PRORP causality in four independent families.

GGPS1

Gene: GGPS1 hgnc:4249 relationship_type: CAUSATIVE

Show evidence (1 reference)

PMID:32403198 SUPPORT Human Clinical

"A total of 11 patients in 6 families carrying 5 different biallelic pathogenic variants in specific domains of GGPS1 were identified."

Establishes GGPS1 causality across six families.

ERAL1

Gene: ERAL1 hgnc:3424 relationship_type: CAUSATIVE

Show evidence (1 reference)

PMID:28449065 SUPPORT In Vitro

"Moreover, levels of the 12S rRNA were reduced in the patients, and were rescued by lentiviral expression of wild type ERAL1."

Rescue experiment confirming that the ERAL1 variant causes the molecular phenotype.

RMND1

Gene: RMND1 hgnc:21176 relationship_type: CAUSATIVE

Show evidence (1 reference)

PMID:32911714 SUPPORT Human Clinical

"Our study presents the mildest, so far reported, RMND1-related phenotype and delivers the first independent confirmation that RMND1 is causally involved in the development of Perrault syndrome with renal involvement."

Provides the independent confirmation establishing RMND1 as a Perrault syndrome gene.

DAP3

Gene: DAP3 hgnc:2673 relationship_type: CAUSATIVE

Show evidence (1 reference)

PMID:39371131 SUPPORT In Vitro

"Lentiviral transduction of fibroblasts from affected individuals with wild-type DAP3 cDNA increased DAP3 mRNA expression, and partially rescued protein levels of MRPS7, MRPS9 and complex I and IV subunits, demonstrating the pathogenicity of the DAP3 variants."

Rescue experiment demonstrating DAP3 variant pathogenicity.

MRPS7

Gene: MRPS7 hgnc:14499 relationship_type: CAUSATIVE

Show evidence (1 reference)

PMID:36421788 SUPPORT Human Clinical

"This second independent report validates that variants in MRPS7 are a cause of syndromic POI/Perrault syndrome."

Provides the second independent report establishing MRPS7 as a Perrault syndrome gene.

TFAM

Gene: TFAM hgnc:11741 relationship_type: UNKNOWN

Show evidence (1 reference)

PMID:32399598 SUPPORT Human Clinical

"The remaining patients had variants in candidate genes such as TFAM, involved in mtDNA transcription, replication, and packaging, and GGPS1 involved in mevalonate/coenzyme Q10 biosynthesis and whose enzymatic product is required for mouse folliculogenesis."

The source explicitly frames TFAM as a candidate gene rather than an established cause, which is why this entry is marked PARTIAL and the relationship_type is UNKNOWN.

PEX6

Gene: PEX6 hgnc:8859 relationship_type: CAUSATIVE

Show evidence (1 reference)

PMID:32399598 SUPPORT Human Clinical

"For the first time, we show that pathogenic variants in PEX6 can present clinically as Perrault syndrome."

Establishes PEX6 as a molecular cause of the Perrault phenotype.

💊

Medical Actions

5

Hearing Aids and Auditory Rehabilitation

Action: Rehabilitation NCIT:C15315

Amplification for aidable hearing loss with speech and language therapy and educational support, fitted early to protect language and cognitive development. Frequently escalated to cochlear implantation as hearing loss progresses. Ototoxic medication, in particular aminoglycosides where an alternative exists, and loud-noise exposure should be avoided in individuals with an already vulnerable cochlea.

Mechanism Target:

BYPASSES Sensorineural Hearing Loss — Amplification compensates for the reduced cochlear output without correcting the underlying hair cell injury.

Show evidence (1 reference)

PMID:32911714 SUPPORT Human Clinical

"She received hearing aids at the age of six; the degree of HL progressed gradually and was accompanied by tinnitus and vertigo from the age of 31."

Documents hearing aid use, and its eventual insufficiency, in a genetically confirmed individual.

Cochlear Implantation

Action: cochlear device implantation Ontology label: Surgical Procedure NCIT:C15329

Surgical implantation of a cochlear implant for severe-to-profound sensorineural hearing loss not adequately served by amplification. Outcomes reported in genetically confirmed Perrault syndrome have been good, including in adults implanted after decades of progressive loss.

Mechanism Target:

BYPASSES Cochlear Hair Cell Mitochondrial Injury and Loss — Direct electrical stimulation of the cochlear nerve bypasses the lost or dysfunctional hair cells entirely.

Show evidence (1 reference)

PMID:32911714 SUPPORT Human Clinical

"Cochlear implantation was performed for the right ear at the age of 34 and for the left ear at the age of 36 with a good outcome."

Documents successful cochlear implantation in genetically confirmed Perrault syndrome.

Oestrogen and Progestogen Replacement Therapy

Action: Hormone Replacement Therapy NCIT:C15599

Agent: oestradiol CHEBI:16469 dydrogesterone CHEBI:31527

Hormone replacement in 46,XX individuals, using incremental oestrogen to induce puberty when required, followed by cyclic oestrogen with a progestogen if the uterus is present. Replacement is continued to the usual age of menopause to limit the bone, cardiovascular and urogenital consequences of prolonged hypo-oestrogenism. This treats the downstream hormone deficiency; it does not restore ovarian reserve.

Mechanism Target:

BYPASSES Hypergonadotropic Ovarian Failure — Exogenous oestrogen and progestogen replace the missing ovarian steroid output, correcting the downstream hypo-oestrogenic state without restoring follicular function.

Show evidence (1 reference)

PMID:32911714 SUPPORT Human Clinical

"Both receive oestradiol and dydrogesterone supplementation to reduce the complications of POI."

Documents combined oestrogen and progestogen replacement given specifically to reduce the complications of premature ovarian insufficiency.

Assisted Reproduction with Donor Oocytes

Action: Assisted Reproductive Technology NCIT:C93282

Donor-oocyte in vitro fertilisation is the most reliable fertility option once the follicle pool is exhausted. Oocyte or embryo cryopreservation may be considered while residual ovarian reserve remains, which requires diagnosis and counselling before reserve is lost — an argument for prepubertal surveillance of girls with unexplained bilateral sensorineural hearing loss.

Mechanism Target:

BYPASSES Female Infertility — Donor oocytes bypass the depleted follicle pool without restoring ovarian function.

Show evidence (1 reference)

PMID:36421788 SUPPORT Human Clinical

"POI is a common cause of infertility, characterised by elevated follicle-stimulating hormone and amenorrhea in women under the age of 40."

Establishes the infertility that assisted reproduction addresses; the specific donor-oocyte recommendation derives from clinical management guidance rather than this report, so support is marked PARTIAL.

Genetic Counselling

Action: Genetic Counseling NCIT:C15240

Counselling for the 25 per cent sibling recurrence risk of an autosomal recessive disorder, with cascade testing of at-risk relatives. Counselling must address the sex-limited expression explicitly: a 46,XY sibling inheriting both alleles is at risk of hearing loss but generally not of gonadal disease, and a 46,XX sibling should be offered pubertal and ovarian-reserve surveillance before reproductive decisions are needed. Preimplantation or prenatal testing is available once familial variants are known.

Show evidence (1 reference)

PMID:34338890 SUPPORT Human Clinical

"Perrault syndrome is inherited as an autosomal recessive disorder characterized by bilateral mild to severe childhood sensorineural hearing loss with variable age of onset in both sexes and ovarian dysfunction in females who have a 46, XX karyotype."

Establishes the recessive inheritance and sex-limited expression that determine the content of counselling.

🔬

Biochemical Markers

1

Elevated Serum Follicle-Stimulating Hormone (INCREASED)

Show evidence (1 reference)

PMID:36421788 SUPPORT Human Clinical

"POI is a common cause of infertility, characterised by elevated follicle-stimulating hormone and amenorrhea in women under the age of 40."

Defines elevated FSH with amenorrhoea as the diagnostic biochemical criterion for the ovarian phenotype.

🔬

Diagnosis

2

Pure-Tone Audiometry with Auditory Brainstem Response

Comprehensive audiological assessment including pure-tone audiometry, tympanometry, otoacoustic emissions, acoustic reflexes and auditory brainstem responses. Brainstem-response testing is essential because a subset of individuals, particularly those with TWNK variants, have an auditory-neuropathy pattern that pure-tone audiometry alone will underestimate. Serial testing is required because hearing loss is often progressive and can be late-onset.

Show evidence (1 reference)

PMID:39340975 SUPPORT Human Clinical

"These cases highlight the importance of detailed hearing tests, including auditory brainstem response and genetic tests in patients with Perrault syndrome, even in cases of mild hearing loss, for accurate diagnosis and appropriate management."

Directly recommends auditory brainstem response testing in suspected Perrault syndrome.

Comprehensive Genomic Sequencing

Because the disorder is caused by at least fifteen genes and known genes explain only about half of clinically diagnosed individuals, a comprehensive hearing-loss / premature-ovarian-insufficiency / mitochondrial gene panel or exome/genome sequencing with copy-number analysis is the appropriate first-line molecular test. Karyotype and FMR1 premutation testing remain part of the wider evaluation of premature ovarian insufficiency to exclude the principal non-Perrault causes.

Show evidence (1 reference)

PMID:34338890 SUPPORT Human Clinical

"Variants of these eight genes only account for approximately half of the individuals with clinical features of Perrault syndrome where the molecular genetic base remains under investigation."

Establishes the incomplete diagnostic yield that motivates broad genomic rather than targeted testing.

📊

Prevalence

1

Worldwide

Point Prevalence Ultra Rare

No reliable population-based prevalence, incidence or carrier frequency has been established. Perrault syndrome is consistently described as rare, with published cases numbering in the low hundreds and drawn from selectively ascertained deafness and premature-ovarian-insufficiency clinics. Under-ascertainment in 46,XY individuals, who lack the gonadal phenotype, means any published figure is a lower bound.

Show evidence (1 reference)

PMID:42283975 SUPPORT Human Clinical

"The cohort demonstrates a distribution of 56.1% homozygous and 43.9% compound heterozygous variants, reflecting diverse ancestral backgrounds and potential selective pressures against deleterious alleles."

The largest synthesis available reports only aggregate genotype proportions across a literature cohort, with no population denominator, supporting the assessment that prevalence is unquantified and the disorder ultra-rare.

🔀

Differential Diagnoses

7

Conditions with similar clinical presentations that must be differentiated from Perrault Syndrome:

46,XX gonadal dysgenesis MONDO:0009299

Overlapping Features The closest ovarian-side boundary and the most important one to draw correctly. Both present with hypergonadotropic ovarian failure in a 46,XX individual, and the dismech entry for 46,XX gonadal dysgenesis already lists Perrault syndrome as a differential; the two entries are deliberately kept separate rather than merged.

Distinguishing Features

Sensorineural hearing loss is required for Perrault syndrome and is absent in isolated 46,XX gonadal dysgenesis.
46,XX gonadal dysgenesis is confined to the gonad; Perrault syndrome is a multisystem mitochondrial disorder that may add ataxia, neuropathy, renal or muscular disease.
The numbered ovarian-dysgenesis gene series is distinct from the Perrault gene set, and NR5A1-related disease belongs with neither.
Male relatives are unaffected in 46,XX gonadal dysgenesis but have hearing loss in Perrault syndrome, so a deaf brother is a strong pointer to Perrault syndrome.

Show evidence (1 reference)

PMID:34338890 SUPPORT Human Clinical

"Perrault syndrome is inherited as an autosomal recessive disorder characterized by bilateral mild to severe childhood sensorineural hearing loss with variable age of onset in both sexes and ovarian dysfunction in females who have a 46, XX karyotype."

The obligatory bilateral hearing loss in both sexes is the discriminating feature against isolated 46,XX gonadal dysgenesis.

Turner syndrome MONDO:0019499

Overlapping Features The commonest cause of hypergonadotropic ovarian failure and a genuine mimic, because a majority of adults with Turner syndrome also develop progressive high-tone sensorineural hearing loss, reproducing both cardinal Perrault features in one individual.

Distinguishing Features

Karyotype is 45,X or a structural X abnormality, not 46,XX; karyotype or chromosomal microarray settles the distinction.
Short stature, lymphoedema, webbed neck, coarctation and bicuspid aortic valve are Turner features not seen in Perrault syndrome.
Turner syndrome is a chromosomal disorder and is generally sporadic; Perrault syndrome is autosomal recessive with a 25 per cent sibling recurrence risk.
Male relatives cannot be affected in Turner syndrome, whereas Perrault syndrome affects 46,XY relatives with hearing loss.

Show evidence (1 reference)

PMID:42283975 SUPPORT Human Clinical

"Perrault syndrome is a genetically and clinically diverse autosomal recessive disorder characterized by sensorineural hearing loss in both sexes and primary ovarian insufficiency in females."

Establishes the autosomal recessive, both-sexes character that separates Perrault syndrome from a sex-chromosome aneuploidy.

FMR1 premutation-associated primary ovarian insufficiency MONDO:0010706

Overlapping Features The commonest single-gene cause of premature ovarian insufficiency and a mandatory exclusion in any woman presenting with it, including one being evaluated for Perrault syndrome.

Distinguishing Features

Caused by an FMR1 CGG repeat premutation, detected by targeted repeat sizing rather than sequencing, so a negative gene panel does not exclude it.
X-linked transmission with premutation carriers in the maternal line, not autosomal recessive.
Sensorineural hearing loss is not a feature; associated findings are fragile X-associated tremor/ataxia syndrome in older carriers and fragile X syndrome in expanded offspring.

Show evidence (1 reference)

PMID:34338890 SUPPORT Human Clinical

"Hearing loss and impaired fertility are common human disorders each with multiple genetic causes."

Frames the central diagnostic problem — each cardinal feature is independently common — which is why the principal isolated causes of premature ovarian insufficiency such as the FMR1 premutation must be excluded before invoking a single recessive syndrome.

Autoimmune polyendocrine syndrome type 1 MONDO:0009411

Overlapping Features The principal autoimmune cause of premature ovarian insufficiency, caused by biallelic AIRE variants. Like Perrault syndrome it is recessive and multisystem, so it is not excluded by inheritance pattern alone.

Distinguishing Features

Chronic mucocutaneous candidiasis and hypoparathyroidism with adrenal insufficiency form the defining triad; none occurs in Perrault syndrome.
Ovarian failure is autoimmune, with detectable steroid-cell and 21-hydroxylase autoantibodies, rather than a primary germ-cell energetic defect.
Sensorineural hearing loss is not a feature.

Show evidence (1 reference)

PMID:36421788 SUPPORT Human Clinical

"Here we describe a patient with POI, sensorineural hearing loss and Hashimoto's disease. The co-occurrence of POI with sensorineural hearing loss indicates Perrault syndrome."

Illustrates the diagnostic trap directly: coexisting autoimmune endocrinopathy can suggest an autoimmune cause, yet the hearing-loss plus ovarian-insufficiency combination still indicated Perrault syndrome on molecular testing.

Usher syndrome MONDO:0019501

Overlapping Features The commonest syndromic form of recessive sensorineural hearing loss and therefore a routine alternative when a deaf proband is investigated, particularly before any ovarian phenotype has declared itself.

Distinguishing Features

Progressive retinitis pigmentosa with night blindness and visual field loss is the defining second feature; retinal disease is not part of Perrault syndrome.
Vestibular areflexia is characteristic of Usher type 1 and is not a Perrault feature.
Gonadal function is normal in Usher syndrome, so ovarian assessment discriminates once a 46,XX proband reaches puberty.

Show evidence (1 reference)

PMID:31827252 SUPPORT Human Clinical

"In the families reported here a diagnosis of SNHL revealed variants in a Perrault syndrome related gene, which would not have been suspected based on clinical presentation alone."

Shows that Perrault genotypes are found among probands ascertained purely as hearing loss, the population in which syndromic deafness alternatives such as Usher syndrome are the working differential.

D-bifunctional protein deficiency MONDO:0009855

Overlapping Features An allelic disorder rather than an unrelated mimic: severe biallelic HSD17B4 variants cause D-bifunctional protein deficiency while hypomorphic variants in the same gene cause Perrault syndrome. Curated as a separate dismech entry; the relationship is one of allelic severity, not of coincidental resemblance.

Distinguishing Features

Neonatal hypotonia, intractable seizures and failure to thrive with death usually within the first two years, versus a chronic disorder compatible with normal lifespan.
Elevated very-long-chain fatty acids are consistently abnormal in D-bifunctional protein deficiency and may be normal or only mildly abnormal in HSD17B4 Perrault syndrome.
No female with D-bifunctional protein deficiency has survived past puberty, so the ovarian phenotype cannot be assessed in that disorder.

Show evidence (1 reference)

PMID:20673864 SUPPORT Human Clinical

"Mutations in HSD17B4 are known to cause DBP deficiency, an autosomal-recessive disorder of peroxisomal fatty acid beta-oxidation that is generally fatal within the first two years of life. No females with DBP deficiency surviving past puberty have been reported, and ovarian dysgenesis has not..."

Documents both the allelic relationship and the clinical features that separate the two HSD17B4 phenotypes.

Autosomal dominant progressive external ophthalmoplegia type 3 Not Yet Curated MONDO:0012241

Overlapping Features The TWNK allelic boundary, and the most important nosological trap in this entry. The same gene that causes Perrault syndrome 5 when biallelic hypomorphic variants are present also causes autosomal DOMINANT progressive external ophthalmoplegia type 3, and, with a different set of recessive variants, mitochondrial DNA depletion syndrome 7. These are separate disorders and their literature must not be imported into the Perrault entry.

Distinguishing Features

Inheritance is autosomal DOMINANT with a single heterozygous missense variant; Perrault syndrome 5 requires two variants in trans.
Ptosis and progressive ophthalmoparesis are the presenting features; ophthalmoplegia is not a cardinal Perrault feature.
Ovarian insufficiency in a 46,XX individual, the defining sex-limited Perrault feature, is not part of the PEOA3 phenotype.
The third TWNK phenotype, mitochondrial DNA depletion syndrome 7, presents as infantile-onset spinocerebellar ataxia with epilepsy rather than as hearing loss with ovarian insufficiency.

Show evidence (1 reference)

PMID:25355836 SUPPORT Human Clinical

"Twinkle is known also to harbor multiple mutations, nearly all missenses, leading to dominant progressive external ophthalmoplegia type 3 and to recessive mitochondrial DNA depletion syndrome 7, also known as infantile-onset spinocerebellar ataxia."

Explicitly separates the dominant PEO and mtDNA-depletion phenotypes from the recessive Perrault presentation of the same gene.

{ }

Source YAML

click to show

name: Perrault Syndrome
creation_date: "2026-08-01T05:20:00Z"
category: Mendelian
disease_term:
  preferred_term: Perrault syndrome
  term:
    id: MONDO:0017312
    label: Perrault syndrome
synonyms:
- Perrault syndrome
- XX gonodal dysgenesis-deafness syndrome
- gonadal dysgenesis, XX type, with deafness
- ovarian dysgenesis-sensorineural deafness syndrome
- PRLTS
classifications:
  mechanistic_category:
  - classification_value: mitochondrial disease
description: >-
  Perrault syndrome is a rare, genetically heterogeneous autosomal recessive
  disorder defined by the co-occurrence of bilateral sensorineural hearing loss,
  which affects individuals of both sexes, with ovarian dysfunction that is
  expressed only in individuals who have a 46,XX karyotype. The gonadal
  phenotype ranges from complete ovarian dysgenesis with streak gonads and
  primary amenorrhoea to premature ovarian insufficiency presenting as secondary
  amenorrhoea after apparently normal puberty; in every case it is
  hypergonadotropic. Individuals with a 46,XY karyotype who carry the same
  biallelic genotype have hearing loss with generally preserved gonadal
  function, so the syndromic diagnosis is systematically missed in males and in
  prepubertal girls, who may instead be labelled as having nonsyndromic
  deafness. The disorder is caused by biallelic variants in nuclear genes of
  mitochondrial gene expression and proteostasis — mitochondrial aminoacyl-tRNA
  synthetases (HARS2, LARS2), mitoribosome assembly and components (ERAL1, DAP3,
  MRPS7), mitochondrial tRNA processing (PRORP), mtDNA maintenance (TWNK, TFAM),
  mitochondrial translation support (RMND1) and matrix proteolysis (CLPP) — plus
  two metabolic exceptions, peroxisomal beta-oxidation (HSD17B4, PEX6) and
  isoprenoid biosynthesis (GGPS1). A neurological form, historically termed type
  II, adds progressive ataxia, peripheral neuropathy, developmental delay and
  intellectual disability to the cardinal features present in the isolated type
  I form. Known genes account for only about half of clinically diagnosed
  individuals.
notes: >-
  Nosological scope. This entry models the recessive Perrault phenotype only.
  TWNK (formerly C10orf2) is pleiotropic: dominant missense variants in the same
  gene cause autosomal dominant progressive external ophthalmoplegia type 3
  (PEOA3), and a distinct set of recessive variants causes mitochondrial DNA
  depletion syndrome 7 (infantile-onset spinocerebellar ataxia). Neither of
  those phenotypes is imported here; only the biallelic Perrault presentation is
  curated, and the distinction is documented in the PRLTS5 subtype, the TWNK
  genetic entry and an explicit differential. Similarly, HSD17B4 and PEX6 are
  allelic with severe D-bifunctional protein deficiency and Zellweger-spectrum
  peroxisome biogenesis disorder respectively; those entries are curated
  separately (D-Bifunctional_Protein_Deficiency, Peroxisome_Biogenesis_Disorder)
  and are handled here as differentials and allelic notes rather than
  duplicated. The boundary with 46_XX_Gonadal_Dysgenesis is reciprocal: that
  entry lists Perrault syndrome as a differential and explicitly declines to
  import hearing phenotypes, and this entry correspondingly lists 46,XX gonadal
  dysgenesis as a differential rather than re-curating the numbered ODG series.

  Independently verified gene-to-subtype mapping (OAK against MONDO, August
  2026): PRLTS1 = HSD17B4 (MONDO:0009300, OMIM 233400); PRLTS2 = HARS2
  (MONDO:0013972, OMIM 614926); PRLTS3 = CLPP (MONDO:0013588, OMIM 614129);
  PRLTS4 = LARS2 (MONDO:0014126, OMIM 615300); PRLTS5 = TWNK (MONDO:0014504,
  OMIM 616138); PRLTS6 = ERAL1 (MONDO:0033047, OMIM 617565); PRLTS7 = DAP3
  (MONDO:0976232, OMIM 621101). Note in particular that CLPP is PRLTS3 and LARS2
  is PRLTS4, not the reverse. PRORP, RMND1, GGPS1, MRPS7, PEX6, TFAM, MRPL49 and
  MRPL50 are established or supported Perrault genes that carry no numbered
  PRLTS designation and are therefore modelled as genetic entries without a
  subtype link.

inheritance:
- name: Autosomal recessive inheritance
  inheritance_term:
    preferred_term: Autosomal recessive inheritance
    term:
      id: HP:0000007
      label: Autosomal recessive inheritance
  expressivity: VARIABLE
  penetrance: UNKNOWN
  description: >-
    All established Perrault syndrome genes act recessively; affected
    individuals carry two pathogenic alleles, most often as compound
    heterozygotes or, in consanguineous families, as homozygotes. Biallelic
    complete loss of function has not been observed for the mitochondrial
    translation genes, consistent with those genes being essential, so genotypes
    combine hypomorphic alleles with each other or with a null allele.
    Expressivity is markedly variable between and within families: hearing-loss
    severity, age of onset, degree of ovarian failure and the presence of
    neurological features differ even among siblings sharing a genotype. Sex
    modifies expression but not transmission: hearing loss occurs in both sexes,
    whereas the ovarian phenotype is confined to 46,XX individuals.
  evidence:
  - reference: PMID:34338890
    reference_title: "New insights into Perrault syndrome, a clinically and genetically heterogeneous disorder."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Perrault syndrome is inherited as an autosomal recessive disorder
      characterized by bilateral mild to severe childhood sensorineural hearing
      loss with variable age of onset in both sexes and ovarian dysfunction in
      females who have a 46, XX karyotype.
    explanation: >-
      States the autosomal recessive mode of inheritance and the sex-limited
      expression of the ovarian component in one sentence.
  - reference: PMID:31827252
    reference_title: "A recurrent missense variant in HARS2 results in variable sensorineural hearing loss in three unrelated families."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      This lack of biallelic loss-of-function variants likely indicates that
      HARS2, along with the other Perrault syndrome associated genes, is
      essential and that complete loss-of-function would result in lethality.
    explanation: >-
      Supports the constraint that surviving genotypes retain partial function,
      explaining why hypomorphic alleles dominate the mutational spectrum.

has_subtypes:
- name: PRLTS1
  display_name: Perrault syndrome 1 (HSD17B4)
  description: >-
    Perrault syndrome caused by biallelic HSD17B4 variants. HSD17B4 encodes
    17-beta-hydroxysteroid dehydrogenase type 4, also called D-bifunctional
    protein, a peroxisomal enzyme of fatty acid beta-oxidation. This was the
    first Perrault syndrome gene identified and is the principal peroxisomal
    exception among predominantly mitochondrial causes. Hypomorphic alleles give
    the Perrault phenotype whereas severe alleles give D-bifunctional protein
    deficiency, an allelic disorder curated separately; neurological features are
    characteristic of the HSD17B4 Perrault presentations reported to date.
  mappings:
    mondo_mappings:
    - term:
        id: MONDO:0009300
        label: Perrault syndrome 1
      mapping_predicate: skos:exactMatch
      mapping_source: MONDO
      mapping_justification: >-
        MONDO defines Perrault syndrome 1 as Perrault syndrome caused by
        mutation in HSD17B4 (verified with OAK).
  genes:
  - preferred_term: HSD17B4
    term:
      id: hgnc:5213
      label: HSD17B4
  evidence:
  - reference: PMID:20673864
    reference_title: "Mutations in the DBP-deficiency protein HSD17B4 cause ovarian dysgenesis, hearing loss, and ataxia of Perrault Syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Whole-exome sequencing of genomic DNA from one of these sisters revealed
      exactly one gene with two rare functional variants: HSD17B4, which encodes
      17beta-hydroxysteroid dehydrogenase type 4 (HSD17B4), also known as
      D-bifunctional protein (DBP).
    explanation: Identifies HSD17B4 as the first Perrault syndrome gene.
- name: PRLTS2
  display_name: Perrault syndrome 2 (HARS2)
  description: >-
    Perrault syndrome caused by biallelic HARS2 variants. HARS2 encodes
    mitochondrial histidyl-tRNA synthetase, which charges mitochondrial
    tRNA-His. Hearing loss is often prelingual and progressive and can be the
    only manifestation in affected males and prepubertal girls, so HARS2
    genotypes are a recognised cause of apparently nonsyndromic deafness.
  mappings:
    mondo_mappings:
    - term:
        id: MONDO:0013972
        label: Perrault syndrome 2
      mapping_predicate: skos:exactMatch
      mapping_source: MONDO
      mapping_justification: >-
        MONDO defines Perrault syndrome 2 as Perrault syndrome caused by
        mutation in HARS2 (verified with OAK).
  genes:
  - preferred_term: HARS2
    term:
      id: hgnc:4817
      label: HARS2
  evidence:
  - reference: PMID:21464306
    reference_title: "Mutations in mitochondrial histidyl tRNA synthetase HARS2 cause ovarian dysgenesis and sensorineural hearing loss of Perrault syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      In a nonconsanguineous family with five affected siblings, linkage
      analysis and genomic sequencing revealed the genetic basis of Perrault
      syndrome to be compound heterozygosity for mutations in the mitochondrial
      histidyl tRNA synthetase HARS2 at two highly conserved amino acids, L200V
      and V368L.
    explanation: Establishes HARS2 as a Perrault syndrome gene.
- name: PRLTS3
  display_name: Perrault syndrome 3 (CLPP)
  description: >-
    Perrault syndrome caused by biallelic CLPP variants. CLPP encodes the
    proteolytic subunit of the mitochondrial ATP-dependent CLPXP chambered
    protease, part of the mitochondrial unfolded protein response. Growth
    restriction, epilepsy and other neurological features are frequently
    reported, and CLPP is the gene for which male reproductive involvement is
    best supported by model-organism data.
  mappings:
    mondo_mappings:
    - term:
        id: MONDO:0013588
        label: Perrault syndrome 3
      mapping_predicate: skos:exactMatch
      mapping_source: MONDO
      mapping_justification: >-
        MONDO defines Perrault syndrome 3 as Perrault syndrome caused by
        mutation in CLPP (verified with OAK).
  genes:
  - preferred_term: CLPP
    term:
      id: hgnc:2084
      label: CLPP
  evidence:
  - reference: PMID:23541340
    reference_title: "Perrault syndrome is caused by recessive mutations in CLPP, encoding a mitochondrial ATP-dependent chambered protease."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      By a combination of linkage analysis, homozygosity mapping, and exome
      sequencing in three families, we identified mutations in CLPP as the
      likely cause of this phenotype.
    explanation: Establishes CLPP as a Perrault syndrome gene.
- name: PRLTS4
  display_name: Perrault syndrome 4 (LARS2)
  description: >-
    Perrault syndrome caused by biallelic LARS2 variants. LARS2 encodes
    mitochondrial leucyl-tRNA synthetase. LARS2 is the single most frequent
    cause in molecularly solved cohorts and has the broadest allelic spectrum,
    extending from isolated hearing loss with ovarian insufficiency to
    leukodystrophy and lethal infantile multisystem disease.
  mappings:
    mondo_mappings:
    - term:
        id: MONDO:0014126
        label: Perrault syndrome 4
      mapping_predicate: skos:exactMatch
      mapping_source: MONDO
      mapping_justification: >-
        MONDO defines Perrault syndrome 4 as Perrault syndrome caused by
        mutation in LARS2 (verified with OAK).
  genes:
  - preferred_term: LARS2
    term:
      id: hgnc:17095
      label: LARS2
  evidence:
  - reference: PMID:23541342
    reference_title: "Mutations in LARS2, encoding mitochondrial leucyl-tRNA synthetase, lead to premature ovarian failure and hearing loss in Perrault syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      In two families affected by POF accompanied by hearing loss (together,
      these symptoms compose Perrault syndrome), exome sequencing revealed
      mutations in LARS2, encoding mitochondrial leucyl-tRNA synthetase
    explanation: Establishes LARS2 as a Perrault syndrome gene.
- name: PRLTS5
  display_name: Perrault syndrome 5 (TWNK)
  description: >-
    Perrault syndrome caused by biallelic TWNK (formerly C10orf2) variants. TWNK
    encodes Twinkle, the mitochondrial DNA primase-helicase. Essentially all
    reported individuals have neurological involvement, making this subtype
    prototypically type II, and auditory neuropathy rather than pure cochlear
    loss has been documented. IMPORTANT NOSOLOGICAL NOTE — TWNK is pleiotropic:
    dominant missense variants cause progressive external ophthalmoplegia type
    3, and a different set of recessive variants causes mitochondrial DNA
    depletion syndrome 7. Only the biallelic Perrault presentation belongs to
    this entry.
  mappings:
    mondo_mappings:
    - term:
        id: MONDO:0014504
        label: Perrault syndrome 5
      mapping_predicate: skos:exactMatch
      mapping_source: MONDO
      mapping_justification: >-
        MONDO defines Perrault syndrome 5 as Perrault syndrome caused by
        mutation in TWNK (verified with OAK).
  genes:
  - preferred_term: TWNK
    term:
      id: hgnc:1160
      label: TWNK
  evidence:
  - reference: PMID:25355836
    reference_title: "Mutations in Twinkle primase-helicase cause Perrault syndrome with neurologic features."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Our study identifies Twinkle mutations as a cause of Perrault syndrome
      accompanied by neurologic features and expands the phenotypic spectrum of
      recessive disease caused by mutations in Twinkle.
    explanation: Establishes recessive TWNK variants as a Perrault syndrome cause.
  - reference: PMID:25355836
    reference_title: "Mutations in Twinkle primase-helicase cause Perrault syndrome with neurologic features."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Twinkle is known also to harbor multiple mutations, nearly all missenses,
      leading to dominant progressive external ophthalmoplegia type 3 and to
      recessive mitochondrial DNA depletion syndrome 7, also known as
      infantile-onset spinocerebellar ataxia.
    explanation: >-
      Documents the allelic disorders that must NOT be conflated with the
      recessive Perrault presentation, in particular dominant PEO type 3.
- name: PRLTS6
  display_name: Perrault syndrome 6 (ERAL1)
  description: >-
    Perrault syndrome caused by biallelic ERAL1 variants. ERAL1 encodes a
    GTPase chaperone that binds mitochondrial 12S rRNA and is required for
    assembly of the small mitoribosomal subunit; patient fibroblasts show
    reduced assembled small subunit, reduced 12S rRNA and impaired mitochondrial
    respiration.
  mappings:
    mondo_mappings:
    - term:
        id: MONDO:0033047
        label: Perrault syndrome 6
      mapping_predicate: skos:exactMatch
      mapping_source: MONDO
      mapping_justification: >-
        MONDO Perrault syndrome 6 carries a gene-association relationship to
        ERAL1 (verified with OAK).
  genes:
  - preferred_term: ERAL1
    term:
      id: hgnc:3424
      label: ERAL1
  evidence:
  - reference: PMID:28449065
    reference_title: "A homozygous missense mutation in ERAL1, encoding a mitochondrial rRNA chaperone, causes Perrault syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      We excluded mutations in the known PS genes, but identified a single
      homozygous mutation in the ERAL1 gene (c.707A > T; p.Asn236Ile).
    explanation: Establishes ERAL1 as a Perrault syndrome gene.
- name: PRLTS7
  display_name: Perrault syndrome 7 (DAP3)
  description: >-
    Perrault syndrome caused by biallelic DAP3 variants. DAP3 encodes
    mitoribosomal small subunit protein 29 (MRPS29). Presentations span a
    Perrault-syndrome spectrum through to a severe childhood-onset
    neurometabolic phenotype with combined complex I and IV deficiency; this is
    the most recently designated numbered subtype.
  mappings:
    mondo_mappings:
    - term:
        id: MONDO:0976232
        label: Perrault syndrome 7
      mapping_predicate: skos:exactMatch
      mapping_source: MONDO
      mapping_justification: >-
        MONDO Perrault syndrome 7 carries a gene-association relationship to
        DAP3 (verified with OAK).
  genes:
  - preferred_term: DAP3
    term:
      id: hgnc:2673
      label: DAP3
  evidence:
  - reference: PMID:39371131
    reference_title: "Biallelic variants in DAP3 result in reduced assembly of the mitoribosomal small subunit with altered intrinsic and extrinsic apoptosis and a Perrault syndrome-spectrum phenotype."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Here, we describe five unrelated individuals with biallelic variants in
      the DAP3 nuclear gene encoding mitoribosomal small subunit 29 (MRPS29)
    explanation: Establishes DAP3 as a Perrault syndrome gene.
- name: Type I
  display_name: Type I (isolated Perrault syndrome)
  description: >-
    The isolated clinical form: sensorineural hearing loss plus ovarian
    dysfunction in 46,XX individuals, without significant neurological disease.
    This is a descriptive clinical split, not a molecular one — the same gene can
    give type I in one individual and type II in another, and the boundary is
    increasingly blurred by multisystem presentations.
  evidence:
  - reference: PMID:34338890
    reference_title: "New insights into Perrault syndrome, a clinically and genetically heterogeneous disorder."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Since the initial clinical description of Perrault syndrome 70 years ago,
      the phenotype of some subjects may additionally involve developmental
      delay, intellectual deficit and other neurological disabilities, which can
      vary in severity in part dependent upon the genetic variants and the gene
      involved.
    explanation: >-
      Establishes that neurological involvement is present in only a subset,
      which is the basis for separating the isolated form from the neurological
      form.
- name: Type II
  display_name: Type II (Perrault syndrome with neurological features)
  description: >-
    The neurological clinical form: the cardinal hearing and ovarian features
    plus progressive cerebellar ataxia, peripheral axonal neuropathy,
    hyporeflexia, abnormal eye movements, developmental delay, intellectual
    disability and, in some individuals, cerebral white-matter abnormality or
    leukodystrophy. TWNK and HSD17B4 genotypes are almost always type II;
    severe LARS2 alleles can add leukodystrophy.
  evidence:
  - reference: PMID:25355836
    reference_title: "Mutations in Twinkle primase-helicase cause Perrault syndrome with neurologic features."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      To identify the genetic cause in 2 families of progressive ataxia, axonal
      neuropathy, hyporeflexia, and abnormal eye movements, accompanied by
      progressive hearing loss and ovarian dysgenesis, with a clinical diagnosis
      of Perrault syndrome.
    explanation: >-
      Enumerates the neurological features that define the type II clinical
      form alongside the cardinal features.

pathophysiology:
- name: Biallelic Loss of Mitochondrial Gene-Expression and Proteostasis Factors
  biological_scale: MOLECULAR
  role: trigger
  description: >-
    The initiating lesion is inheritance of two hypomorphic alleles, or one
    hypomorphic plus one null allele, in a nuclear gene whose product supports
    mitochondrial gene expression or protein quality control. Because these
    genes are essential, complete biallelic loss of function has not been
    observed in surviving individuals; residual activity determines whether the
    phenotype is organ-selective Perrault syndrome or a severe infantile
    multisystem mitochondrial disease. Fifteen genes have now been implicated,
    converging on a small number of mitochondrial processes plus two metabolic
    exceptions.
  genes:
  - preferred_term: LARS2
    term:
      id: hgnc:17095
      label: LARS2
  - preferred_term: HARS2
    term:
      id: hgnc:4817
      label: HARS2
  - preferred_term: CLPP
    term:
      id: hgnc:2084
      label: CLPP
  - preferred_term: TWNK
    term:
      id: hgnc:1160
      label: TWNK
  - preferred_term: HSD17B4
    term:
      id: hgnc:5213
      label: HSD17B4
  - preferred_term: ERAL1
    term:
      id: hgnc:3424
      label: ERAL1
  - preferred_term: DAP3
    term:
      id: hgnc:2673
      label: DAP3
  - preferred_term: PRORP
    term:
      id: hgnc:19958
      label: PRORP
  - preferred_term: RMND1
    term:
      id: hgnc:21176
      label: RMND1
  - preferred_term: GGPS1
    term:
      id: hgnc:4249
      label: GGPS1
  - preferred_term: MRPS7
    term:
      id: hgnc:14499
      label: MRPS7
  - preferred_term: PEX6
    term:
      id: hgnc:8859
      label: PEX6
  evidence:
  - reference: PMID:42283975
    reference_title: "Comprehensive Insights into Perrault Syndrome: Genetic Diversity and Clinical Implications."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      highlighting mutations in fifteen principal genes: HSD17B4, HARS2, CLPP,
      LARS2, TWNK, ERAL1, RMND1, DAP3, PRORP, MRPL50, MRPL49, MRPS7, PEX6,
      GGPS1, and TFAM. Each of these genes plays a critical role either in
      mitochondrial function or peroxisomal processes, central to cellular
      energy metabolism and biosynthesis pathways.
    explanation: >-
      Enumerates the causal gene set and states that all converge on
      mitochondrial or peroxisomal function.
  downstream:
  - target: Impaired Mitochondrial Translation and RNA Maturation
    description: >-
      Loss of aminoacyl-tRNA synthetase, mitoribosome-assembly, tRNA-processing
      or translation-support function directly reduces mitochondrial protein
      synthesis.
    causal_link_type: DIRECT
  - target: Mitochondrial Matrix Proteostasis Failure
    description: >-
      Loss of the CLPP proteolytic subunit removes the degradative arm of
      mitochondrial protein quality control.
    causal_link_type: DIRECT
  - target: Mitochondrial DNA Maintenance Failure
    description: >-
      Loss of Twinkle helicase or TFAM function impairs replication and
      packaging of the mitochondrial genome.
    causal_link_type: DIRECT
  - target: Peroxisomal Fatty Acid Beta-Oxidation Failure
    description: >-
      HSD17B4 and PEX6 lesions act through peroxisomal fatty acid beta-oxidation
      rather than through mitochondrial gene expression.
    causal_link_type: DIRECT
  - target: Isoprenoid Synthesis and Protein Prenylation Failure
    description: >-
      GGPS1 lesions act through the mevalonate/isoprenoid pathway and loss of
      protein prenylation, a mechanism distinct from both mitochondrial gene
      expression and peroxisomal beta-oxidation.
    causal_link_type: DIRECT

- name: Impaired Mitochondrial Translation and RNA Maturation
  biological_scale: MOLECULAR
  role: mediator
  description: >-
    The dominant mechanistic axis. Mitochondrial aminoacyl-tRNA synthetases
    HARS2 and LARS2 charge mitochondrial tRNA-His and tRNA-Leu; PRORP is the
    metallonuclease subunit of mitochondrial RNase P and performs 5' end
    processing of precursor tRNAs; ERAL1, DAP3/MRPS29 and MRPS7 build the small
    mitoribosomal subunit; RMND1 tethers mitoribosomes near sites of transcript
    maturation. Reduced activity in any of these steps lowers the rate or
    fidelity of synthesis of the thirteen mtDNA-encoded oxidative
    phosphorylation subunits.
  biological_processes:
  - preferred_term: mitochondrial translation
    term:
      id: GO:0032543
      label: mitochondrial translation
    modifier: DECREASED
  - preferred_term: tRNA aminoacylation for mitochondrial protein translation
    term:
      id: GO:0070127
      label: tRNA aminoacylation for mitochondrial protein translation
    modifier: DECREASED
  - preferred_term: mitochondrial tRNA processing
    term:
      id: GO:0090646
      label: mitochondrial tRNA processing
    modifier: DECREASED
  - preferred_term: mitochondrial small ribosomal subunit assembly
    term:
      id: GO:0180026
      label: mitochondrial small ribosomal subunit assembly
    modifier: DECREASED
  cellular_components:
  - preferred_term: mitochondrial matrix
    term:
      id: GO:0005759
      label: mitochondrial matrix
  evidence:
  - reference: PMID:23541342
    reference_title: "Mutations in LARS2, encoding mitochondrial leucyl-tRNA synthetase, lead to premature ovarian failure and hearing loss in Perrault syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      After HARS2, LARS2 is the second gene encoding mitochondrial tRNA
      synthetase to be found to harbor mutations leading to Perrault syndrome,
      further supporting a critical role for mitochondria in the maintenance of
      ovarian function and hearing.
    explanation: >-
      Establishes mitochondrial tRNA charging, and therefore mitochondrial
      translation, as the shared mechanism of the two synthetase subtypes.
  - reference: PMID:34715011
    reference_title: "Bi-allelic variants in the mitochondrial RNase P subunit PRORP cause mitochondrial tRNA processing defects and pleiotropic multisystem presentations."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      Fibroblasts from affected individuals in two families demonstrated
      decreased steady state levels of PRORP, an accumulation of unprocessed
      mitochondrial transcripts, and decreased steady state levels of
      mitochondrial-encoded proteins, which were rescued by introduction of the
      wild-type PRORP cDNA.
    explanation: >-
      Direct patient-cell evidence that a Perrault gene defect blocks
      mitochondrial RNA maturation and lowers mitochondrial protein output, with
      rescue confirming causality.
  - reference: PMID:28449065
    reference_title: "A homozygous missense mutation in ERAL1, encoding a mitochondrial rRNA chaperone, causes Perrault syndrome."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      Complexome profiling of the cells showed an overall decrease in the levels
      of assembled small ribosomal subunit, indicating that the ERAL1 variant
      affects mitochondrial ribosome assembly.
    explanation: >-
      Patient-fibroblast evidence for the mitoribosome-assembly arm of the same
      translational axis.
  downstream:
  - target: Combined Oxidative Phosphorylation Deficiency and Bioenergetic Stress
    description: >-
      Reduced synthesis of mtDNA-encoded subunits limits assembly of respiratory
      chain complexes I, III, IV and V.
    causal_link_type: DIRECT

- name: Mitochondrial Matrix Proteostasis Failure
  biological_scale: MOLECULAR
  role: mediator
  description: >-
    CLPP encodes the peptidase subunit of the CLPXP complex, the principal
    ATP-dependent protease of the mitochondrial matrix and an effector arm of
    the mitochondrial unfolded protein response. Perrault-associated
    substitutions cluster in a short region and are predicted to distort the
    barrel chamber that captures unfolded substrates. Loss of proteolysis allows
    damaged and unassembled matrix proteins to accumulate, and in Clpp-null mice
    the other Perrault proteins ERAL1, Twinkle and HARS2 themselves accumulate,
    indicating that the proteostatic and translational arms of the disease are
    mechanistically coupled rather than independent.
  biological_processes:
  - preferred_term: mitochondrial unfolded protein response
    term:
      id: GO:0034514
      label: mitochondrial unfolded protein response
    modifier: ABNORMAL
  cellular_components:
  - preferred_term: mitochondrial matrix
    term:
      id: GO:0005759
      label: mitochondrial matrix
  evidence:
  - reference: PMID:23541340
    reference_title: "Perrault syndrome is caused by recessive mutations in CLPP, encoding a mitochondrial ATP-dependent chambered protease."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Together with the previous identification of mutations in HARS2, encoding
      mitochondrial histidyl-tRNA synthetase, mutations in CLPP expose
      dysfunction of mitochondrial protein homeostasis as a cause of Perrault
      syndrome.
    explanation: >-
      States that mitochondrial proteostasis, distinct from translation itself,
      is a causal mechanism of the syndrome.
  - reference: PMID:23541340
    reference_title: "Perrault syndrome is caused by recessive mutations in CLPP, encoding a mitochondrial ATP-dependent chambered protease."
    supports: SUPPORT
    evidence_source: COMPUTATIONAL
    snippet: >-
      Crystal-structure modeling suggests that both substitutions would alter
      the structure of the CLPP barrel chamber that captures unfolded proteins
      and exposes them to proteolysis.
    explanation: >-
      Structural modelling linking the specific substitutions to loss of
      substrate capture, i.e. loss of function of the protease.
  downstream:
  - target: Combined Oxidative Phosphorylation Deficiency and Bioenergetic Stress
    description: >-
      Accumulation of damaged matrix proteins compromises respiratory chain
      integrity and mitochondrial function.
    causal_link_type: DIRECT

- name: Mitochondrial DNA Maintenance Failure
  biological_scale: MOLECULAR
  role: mediator
  description: >-
    TWNK encodes Twinkle, the replicative primase-helicase that unwinds
    mitochondrial DNA at the replication fork, and TFAM packages and
    transcribes the mitochondrial genome. Biallelic hypomorphic alleles impair
    mtDNA replication and reduce mtDNA copy number in the tissues that depend
    most heavily on oxidative metabolism, indirectly limiting the template
    available for mitochondrial gene expression. This arm is the most reliably
    neurological, with essentially all reported TWNK Perrault individuals
    manifesting ataxia or neuropathy.
  biological_processes:
  - preferred_term: mitochondrial DNA replication
    term:
      id: GO:0006264
      label: mitochondrial DNA replication
    modifier: DECREASED
  genes:
  - preferred_term: TWNK
    term:
      id: hgnc:1160
      label: TWNK
  - preferred_term: TFAM
    term:
      id: hgnc:11741
      label: TFAM
  evidence:
  - reference: PMID:25355836
    reference_title: "Mutations in Twinkle primase-helicase cause Perrault syndrome with neurologic features."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      C10orf2 encodes Twinkle, a primase-helicase essential for replication of
      mitochondrial DNA.
    explanation: >-
      Identifies the molecular function whose loss constitutes this mechanistic
      arm.
  downstream:
  - target: Combined Oxidative Phosphorylation Deficiency and Bioenergetic Stress
    description: >-
      Reduced mtDNA template limits expression of the thirteen mtDNA-encoded
      respiratory chain subunits.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - Reduced mitochondrial DNA copy number
    - Reduced abundance of mitochondrial transcripts available for translation

- name: Peroxisomal Fatty Acid Beta-Oxidation Failure
  biological_scale: MOLECULAR
  role: mediator
  description: >-
    The first of two metabolic exceptions that reach the Perrault endpoint
    without acting on mitochondrial gene expression. HSD17B4 encodes
    D-bifunctional protein, a core enzyme of peroxisomal fatty acid
    beta-oxidation, and PEX6 is a peroxisome biogenesis factor whose loss
    impairs import of the matrix enzymes that carry out the same pathway.
    Hypomorphic genotypes leave enough residual peroxisomal flux for survival
    beyond infancy, allowing the cochlear and ovarian phenotype to declare
    itself; severe genotypes instead give D-bifunctional protein deficiency or
    Zellweger-spectrum disease.
  biological_processes:
  - preferred_term: fatty acid beta-oxidation using acyl-CoA oxidase
    term:
      id: GO:0033540
      label: fatty acid beta-oxidation using acyl-CoA oxidase
    modifier: DECREASED
  cellular_components:
  - preferred_term: peroxisome
    term:
      id: GO:0005777
      label: peroxisome
  genes:
  - preferred_term: HSD17B4
    term:
      id: hgnc:5213
      label: HSD17B4
  - preferred_term: PEX6
    term:
      id: hgnc:8859
      label: PEX6
  evidence:
  - reference: PMID:32399598
    reference_title: "Genomic sequencing highlights the diverse molecular causes of Perrault syndrome: a peroxisomal disorder (PEX6), metabolic disorders (CLPP, GGPS1), and mtDNA maintenance/translation disorders (LARS2, TFAM)."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      For the first time, we show that pathogenic variants in PEX6 can present
      clinically as Perrault syndrome. PEX6 encodes a peroxisomal biogenesis
      factor, and we demonstrate evidence of peroxisomal dysfunction in patient
      serum.
    explanation: >-
      Establishes the peroxisomal arm as a genuine molecular cause of the
      Perrault phenotype, with biochemical confirmation of peroxisomal
      dysfunction.
  - reference: PMID:20673864
    reference_title: "Mutations in the DBP-deficiency protein HSD17B4 cause ovarian dysgenesis, hearing loss, and ataxia of Perrault Syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      HSD17B4/DBP is a multifunctional peroxisomal enzyme involved in fatty acid
      beta-oxidation and steroid metabolism.
    explanation: >-
      Identifies the peroxisomal beta-oxidation function whose loss constitutes
      this arm.
  downstream:
  - target: Cochlear Hair Cell Mitochondrial Injury and Loss
    description: >-
      Peroxisomal lipid-handling failure injures the metabolically active
      cochlear sensory epithelium.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - Accumulation of unoxidised very-long-chain fatty acids in metabolically active sensory tissue
  - target: Ovarian Germ Cell Depletion and Follicular Failure
    description: >-
      Impaired peroxisomal lipid and steroid handling compromises ovarian
      somatic and germ cell function.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - Impaired peroxisomal lipid handling in ovarian somatic and germ cells

- name: Isoprenoid Synthesis and Protein Prenylation Failure
  biological_scale: MOLECULAR
  role: mediator
  description: >-
    The second metabolic exception, mechanistically unrelated to the peroxisomal
    arm. GGPS1 encodes geranylgeranyl diphosphate synthase in the
    mevalonate/isoprenoid pathway; its product geranylgeranyl pyrophosphate is
    the lipid anchor required to prenylate small GTPases and is separately
    required for murine folliculogenesis. Loss of prenylation therefore produces
    a distinctive triad of muscular dystrophy with sensorineural hearing loss
    and ovarian insufficiency, the muscle component being unique to this arm.
  biological_processes:
  - preferred_term: protein prenylation
    term:
      id: GO:0018342
      label: protein prenylation
    modifier: DECREASED
  genes:
  - preferred_term: GGPS1
    term:
      id: hgnc:4249
      label: GGPS1
  evidence:
  - reference: PMID:32403198
    reference_title: "GGPS1 Mutations Cause Muscular Dystrophy/Hearing Loss/Ovarian Insufficiency Syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      GGPS1 encodes geranylgeranyl diphosphate synthase in the
      mevalonate/isoprenoid pathway, which catalyzes the synthesis of
      geranylgeranyl pyrophosphate, the lipid precursor of geranylgeranylated
      proteins including small guanosine triphosphatases.
    explanation: >-
      Establishes the isoprenoid arm and the specific biochemical step it
      disrupts.
  - reference: PMID:32403198
    reference_title: "GGPS1 Mutations Cause Muscular Dystrophy/Hearing Loss/Ovarian Insufficiency Syndrome."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      There was delayed membrane healing after laser injury in patient-derived
      myogenic cells,
    explanation: >-
      Functional evidence for the prenylation-dependent membrane-repair defect
      that gives this arm its muscle phenotype.
  downstream:
  - target: Cochlear Hair Cell Mitochondrial Injury and Loss
    description: >-
      Loss of prenylation-dependent signalling injures the cochlear sensory
      epithelium, producing congenital hearing loss in nearly all GGPS1 cases.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - Loss of prenylation-dependent small GTPase signalling
  - target: Ovarian Germ Cell Depletion and Follicular Failure
    description: >-
      Geranylgeranyl pyrophosphate is required for folliculogenesis, so its
      depletion causes ovarian insufficiency.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - Loss of geranylgeranyl pyrophosphate required for folliculogenesis
  - target: Proximal Muscle Weakness
    description: >-
      Impaired prenylation-dependent sarcolemmal membrane repair produces the
      dystrophic muscle phenotype unique to the GGPS1 arm.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - Impaired sarcolemmal membrane repair in prenylation-deficient myofibres

- name: Combined Oxidative Phosphorylation Deficiency and Bioenergetic Stress
  biological_scale: CELLULAR
  role: central_effector
  description: >-
    The convergence point of the mitochondrial arms. Reduced synthesis,
    maturation or quality control of mtDNA-encoded subunits produces a combined
    respiratory chain deficiency, most consistently affecting complexes I and
    IV, with reduced cellular respiration, elevated reactive oxygen species and
    proteostatic stress. Cell types with high and sustained oxidative demand and
    little regenerative capacity — cochlear hair cells, oocytes and long
    peripheral and cerebellar neurons — are selectively vulnerable, which is why
    a defect in a ubiquitously expressed housekeeping gene produces an
    organ-selective syndrome.
  biological_processes:
  - preferred_term: oxidative phosphorylation
    term:
      id: GO:0006119
      label: oxidative phosphorylation
    modifier: DECREASED
  cellular_components:
  - preferred_term: mitochondrion
    term:
      id: GO:0005739
      label: mitochondrion
  evidence:
  - reference: PMID:28449065
    reference_title: "A homozygous missense mutation in ERAL1, encoding a mitochondrial rRNA chaperone, causes Perrault syndrome."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      At the physiological level, mitochondrial respiration was markedly
      decreased in PS fibroblasts, confirming disturbed mitochondrial function.
    explanation: >-
      Direct patient-cell measurement of the bioenergetic deficit downstream of
      a Perrault gene defect.
  - reference: PMID:39371131
    reference_title: "Biallelic variants in DAP3 result in reduced assembly of the mitoribosomal small subunit with altered intrinsic and extrinsic apoptosis and a Perrault syndrome-spectrum phenotype."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      Assessment of respiratory chain function and proteomic profiling of
      fibroblasts from affected individuals demonstrated reduced MRPS29 protein
      levels, and consequently decreased levels of additional protein components
      of the mitoribosomal small subunit, associated with a combined complex I
      and IV deficiency.
    explanation: >-
      Demonstrates that a mitoribosomal Perrault lesion produces a combined
      complex I and IV deficiency.
  downstream:
  - target: Cochlear Hair Cell Mitochondrial Injury and Loss
    description: >-
      Cochlear hair cells have exceptionally high oxidative demand and are
      postmitotic, so they decompensate first.
    causal_link_type: DIRECT
  - target: Ovarian Germ Cell Depletion and Follicular Failure
    description: >-
      Oocytes carry the largest mitochondrial complement of any human cell and
      the non-renewable follicle pool cannot be replaced once depleted.
    causal_link_type: DIRECT
  - target: Neuronal and Axonal Degeneration
    description: >-
      Long peripheral axons and cerebellar circuits fail when oxidative capacity
      falls below their sustained demand, producing the type II phenotype.
    causal_link_type: DIRECT
  - target: Chronic Kidney Disease
    description: >-
      Renal tubular epithelium is oxidative-phosphorylation dependent; renal
      involvement is characteristic of the RMND1 arm.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - Energy failure in oxidative-phosphorylation-dependent renal tubular epithelium

- name: Cochlear Hair Cell Mitochondrial Injury and Loss
  biological_scale: CELLULAR
  role: effector
  conforms_to: "sensorineural_hair_cell_loss#Hair Cell Mechanotransduction Failure and Death"
  description: >-
    Cochlear inner and outer hair cells accumulate morphologically abnormal
    mitochondria, generate excess reactive oxygen species and activate the
    mitochondrial apoptotic pathway. Synaptic function deteriorates before
    frank cell loss: in conditional Hars2-knockout mice, inner hair cells show
    reduced calcium influx and compromised sustained exocytosis at postnatal day
    30, weeks before hair cell death, and outer hair cells ultimately suffer the
    greater loss. In some genotypes, notably TWNK, the deficit is
    retrocochlear or synaptic rather than purely sensory, presenting as auditory
    neuropathy with preserved otoacoustic emissions but absent auditory brainstem
    responses.
  cell_types:
  - preferred_term: cochlear inner hair cell
    term:
      id: CL:0000589
      label: cochlear inner hair cell
  - preferred_term: cochlear outer hair cell
    term:
      id: CL:0000601
      label: cochlear outer hair cell
  locations:
  - preferred_term: cochlea
    term:
      id: UBERON:0001844
      label: cochlea
  biological_processes:
  - preferred_term: sensory perception of sound
    term:
      id: GO:0007605
      label: sensory perception of sound
    modifier: DECREASED
  - preferred_term: apoptotic process
    term:
      id: GO:0006915
      label: apoptotic process
    modifier: INCREASED
  evidence:
  - reference: PMID:34975414
    reference_title: "Disruption of Hars2 in Cochlear Hair Cells Causes Progressive Mitochondrial Dysfunction and Hearing Loss in Mice."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      Taken together, our results suggest that conditional knockout of Hars2 in
      mouse cochlear hair cells leads to accumulating mitochondrial dysfunction
      and ROS stress, triggers progressive hearing loss highlighted by hair cell
      synaptopathy and apoptosis, and is differentially perceived by inner and
      outer hair cells.
    explanation: >-
      Mouse conditional knockout of a Perrault gene establishes hair-cell
      mitochondrial dysfunction and apoptosis as the cochlear mechanism.
  - reference: PMID:34975414
    reference_title: "Disruption of Hars2 in Cochlear Hair Cells Causes Progressive Mitochondrial Dysfunction and Hearing Loss in Mice."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      Targeted knockout of Hars2 in mouse hair cells resulted in delayed onset
      (P30), rapidly progressive hearing loss similar to the PRLTS2 hearing
      phenotype.
    explanation: >-
      Shows the model recapitulates the delayed-onset, progressive character of
      human PRLTS2 hearing loss.
  downstream:
  - target: Sensorineural Hearing Loss
    description: >-
      Loss of hair cell transduction and synaptic output produces the cardinal
      audiological outcome.
    causal_link_type: DIRECT
  - target: Auditory Neuropathy Pattern
    description: >-
      Where the lesion is at the inner hair cell synapse or cochlear nerve
      rather than at the outer hair cell, the audiological signature is auditory
      neuropathy with preserved otoacoustic emissions.
    causal_link_type: DIRECT

- name: Ovarian Germ Cell Depletion and Follicular Failure
  biological_scale: CELLULAR
  role: effector
  description: >-
    Oogonia, oocytes and their granulosa support cells fail to survive or to
    sustain folliculogenesis. The severity of the germ cell deficit sets the
    clinical severity: near-complete prenatal or early postnatal germ cell loss
    yields streak or absent ovaries and primary amenorrhoea, whereas partial
    depletion leaves a reduced follicle pool that is exhausted prematurely and
    presents as secondary amenorrhoea after normal menarche. Because the human
    follicle pool is fixed before birth and not renewed, the loss is
    irreversible. Cross-species data support the requirement: RNAi knockdown of
    the C. elegans ERAL1 orthologue almost abolishes egg production.
  cell_types:
  - preferred_term: oocyte
    term:
      id: CL:0000023
      label: oocyte
  - preferred_term: granulosa cell
    term:
      id: CL:0000501
      label: granulosa cell
  locations:
  - preferred_term: ovary
    term:
      id: UBERON:0000992
      label: ovary
  biological_processes:
  - preferred_term: ovarian follicle development
    term:
      id: GO:0001541
      label: ovarian follicle development
    modifier: DECREASED
  - preferred_term: oocyte development
    term:
      id: GO:0048599
      label: oocyte development
    modifier: DECREASED
  evidence:
  - reference: PMID:28449065
    reference_title: "A homozygous missense mutation in ERAL1, encoding a mitochondrial rRNA chaperone, causes Perrault syndrome."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      Finally, knockdown of the C. elegans ERAL1 homologue E02H1.2 almost
      completely blocked egg production in worms, mimicking the compromised
      fertility in PS-affected women.
    explanation: >-
      Cross-species evidence that the mitoribosomal defect impairs
      gametogenesis, supporting a germ-cell-autonomous mechanism.
  - reference: PMID:21464306
    reference_title: "Mutations in mitochondrial histidyl tRNA synthetase HARS2 cause ovarian dysgenesis and sensorineural hearing loss of Perrault syndrome."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      In Caenorhabditis elegans, reduced expression by RNAi of the single
      essential histydyl tRNA synthetase hars-1 severely compromised fertility.
    explanation: >-
      Independent cross-species evidence that reduced mitochondrial tRNA
      charging compromises fertility.
  downstream:
  - target: Sex-Limited Expression of the Gonadal Phenotype
    description: >-
      The germ cell deficit becomes a clinically recognised gonadal phenotype
      only in individuals with a 46,XX karyotype.
    causal_link_type: DIRECT
  - target: Ovarian Dysgenesis with Streak Gonads
    description: >-
      Near-complete developmental germ cell loss leaves dysplastic, streak or
      absent ovaries.
    causal_link_type: DIRECT

- name: Sex-Limited Expression of the Gonadal Phenotype
  biological_scale: ORGANISM
  role: modifier
  description: >-
    The defining and most distinctive feature of the disorder. The same
    biallelic genotype produces hearing loss in both sexes but a clinically
    manifest gonadal phenotype essentially only in 46,XX individuals. The
    mechanistic basis is the asymmetry of mammalian gametogenesis: the female
    germ cell pool is established prenatally, is finite and is not renewed, so a
    chronic bioenergetic deficit in a non-renewable oocyte population produces
    irreversible follicular exhaustion and hypergonadotropic hypogonadism at or
    shortly after puberty. Male germ cells, by contrast, are continuously
    regenerated from spermatogonial stem cells, so 46,XY individuals with the
    same genotype usually have normal gonadal function and normal fertility,
    though azoospermia and undervirilisation are occasionally described and
    CLPP-null mice have a clear meiotic arrest phenotype. This asymmetry is not
    a difference in inheritance — transmission is ordinary autosomal recessive —
    but it has a major ascertainment consequence: affected males and prepubertal
    girls present with what looks like isolated nonsyndromic deafness, so
    Perrault syndrome is systematically under-recognised in males and diagnosed
    late in girls.
  cell_types:
  - preferred_term: oocyte
    term:
      id: CL:0000023
      label: oocyte
  - preferred_term: spermatocyte
    term:
      id: CL:0000017
      label: spermatocyte
  evidence:
  - reference: PMID:34338890
    reference_title: "New insights into Perrault syndrome, a clinically and genetically heterogeneous disorder."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Perrault syndrome is inherited as an autosomal recessive disorder
      characterized by bilateral mild to severe childhood sensorineural hearing
      loss with variable age of onset in both sexes and ovarian dysfunction in
      females who have a 46, XX karyotype.
    explanation: >-
      States the sex-limited expression explicitly: hearing loss in both sexes,
      ovarian dysfunction restricted to a 46,XX karyotype.
  - reference: PMID:31827252
    reference_title: "A recurrent missense variant in HARS2 results in variable sensorineural hearing loss in three unrelated families."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      All affected individuals are either male or prepubertal and as such would
      not present with POI, a cardinal feature of Perrault syndrome.
    explanation: >-
      Directly demonstrates the ascertainment consequence: individuals with a
      Perrault genotype who are male or prepubertal present as nonsyndromic
      hearing loss.
  - reference: PMID:20673864
    reference_title: "Mutations in the DBP-deficiency protein HSD17B4 cause ovarian dysgenesis, hearing loss, and ataxia of Perrault Syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Perrault syndrome is a recessive disorder characterized by ovarian
      dysgenesis in females, sensorineural deafness in both males and females,
      and in some patients, neurological manifestations.
    explanation: >-
      Independent statement of the sex-limited gonadal component alongside
      sex-independent deafness.
  downstream:
  - target: Hypergonadotropic Ovarian Failure
    description: >-
      In 46,XX individuals the exhausted follicle pool cannot generate adequate
      oestradiol or inhibin, releasing pituitary gonadotropin secretion from
      negative feedback.
    causal_link_type: DIRECT
  - target: Male Infertility
    description: >-
      In the minority of 46,XY individuals in whom the germ line is affected,
      the same energetic deficit impairs spermatogenesis; this remains an
      uncommon, genotype-restricted outcome.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - Genotype-restricted meiotic arrest of spermatocytes, best documented for CLPP

- name: Neuronal and Axonal Degeneration
  biological_scale: TISSUE
  role: effector
  description: >-
    In the type II form, the bioenergetic deficit additionally compromises
    neurons with the longest axons and the highest sustained metabolic demand.
    Cerebellar Purkinje circuits and long peripheral sensory and motor axons
    degenerate, producing progressive ataxia, distal axonal neuropathy,
    hyporeflexia and abnormal eye movements; more severe alleles, particularly
    of LARS2 and PRORP, additionally produce cerebral white-matter abnormality
    or frank leukodystrophy, and developmental delay or intellectual disability
    when onset is early.
  cell_types:
  - preferred_term: Purkinje cell
    term:
      id: CL:0000121
      label: Purkinje cell
  locations:
  - preferred_term: cerebellum
    term:
      id: UBERON:0002037
      label: cerebellum
  evidence:
  - reference: PMID:31827252
    reference_title: "A recurrent missense variant in HARS2 results in variable sensorineural hearing loss in three unrelated families."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      In some cases of Perrault syndrome additional neurological features,
      including peripheral neuropathy, cerebellar ataxia, and intellectual
      disability have also been identified
    explanation: >-
      Enumerates the neurological features that constitute the type II arm.
  - reference: PMID:34715011
    reference_title: "Bi-allelic variants in the mitochondrial RNase P subunit PRORP cause mitochondrial tRNA processing defects and pleiotropic multisystem presentations."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Affected individuals presented with variable phenotypes comprising
      sensorineural hearing loss, primary ovarian insufficiency, developmental
      delay, and brain white matter changes.
    explanation: >-
      Documents developmental delay and cerebral white-matter change as part of
      the neurological arm.
  downstream:
  - target: Cerebellar Ataxia
    description: >-
      Cerebellar degeneration produces the progressive ataxia of type II
      disease.
    causal_link_type: DIRECT
  - target: Peripheral Axonal Neuropathy
    description: >-
      Distal degeneration of long peripheral axons produces a length-dependent
      neuropathy.
    causal_link_type: DIRECT
  - target: Hyporeflexia
    description: >-
      Loss of afferent and efferent conduction in degenerating peripheral axons
      abolishes deep tendon reflexes.
    causal_link_type: DIRECT
  - target: Intellectual Disability
    description: >-
      Early and severe central involvement impairs cognitive development.
    causal_link_type: DIRECT
  - target: Global Developmental Delay
    description: >-
      Early-onset central nervous system involvement delays motor, language and
      cognitive milestones.
    causal_link_type: DIRECT
  - target: Cerebral White Matter Abnormality
    description: >-
      Oligodendrocyte and axonal energy failure produces white-matter signal
      change, reaching frank leukodystrophy with severe alleles.
    causal_link_type: DIRECT
  - target: Abnormal Eye Movements
    description: >-
      Degeneration of cerebellar and brainstem oculomotor circuits produces the
      abnormal eye movements reported alongside ataxia in type II disease.
    causal_link_type: DIRECT

- name: Sensorineural Hearing Loss
  biological_scale: ORGANISM
  role: outcome
  conforms_to: "sensorineural_hair_cell_loss#Progressive Sensorineural Hearing Loss"
  description: >-
    The sex-independent cardinal manifestation. Loss is bilateral and ranges
    from profound with prelingual onset to moderate with early-childhood or even
    adult onset; it is frequently progressive. Middle-ear function is normal.
  evidence:
  - reference: PMID:42283975
    reference_title: "Comprehensive Insights into Perrault Syndrome: Genetic Diversity and Clinical Implications."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Perrault syndrome is a genetically and clinically diverse autosomal
      recessive disorder characterized by sensorineural hearing loss in both
      sexes and primary ovarian insufficiency in females.
    explanation: Establishes hearing loss as a defining, sex-independent outcome.
  downstream:
  - target: Bilateral Sensorineural Hearing Impairment
    description: >-
      The audiological outcome is recorded clinically as bilateral sensorineural
      hearing impairment.
    causal_link_type: DIRECT
  - target: Progressive Hearing Loss
    description: >-
      Continuing hair cell attrition drives progression of the threshold
      elevation over time.
    causal_link_type: DIRECT

- name: Hypergonadotropic Ovarian Failure
  biological_scale: ORGANISM
  role: outcome
  description: >-
    The 46,XX-restricted cardinal manifestation. Loss of ovarian follicular
    function removes oestradiol and inhibin feedback, so pituitary FSH and LH
    rise, producing hypergonadotropic hypogonadism. The clinical presentation
    depends on how much ovarian tissue was ever functional: absent spontaneous
    puberty with primary amenorrhoea and streak or absent ovaries at the severe
    end, or normal menarche followed by irregular menses and secondary
    amenorrhoea before age 40 at the milder end. Consequences beyond infertility
    are those of untreated hypo-oestrogenism — reduced bone density and
    osteoporosis, and adverse cardiovascular and urogenital outcomes.
  evidence:
  - reference: PMID:32767731
    reference_title: "Perrault syndrome: Clinical report and retrospective analysis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The literature review showed that the phenotype for PRLTS4 varies widely,
      but the sensorineural hearing loss, increased gonadotropin levels, and
      amenorrhea occurred frequently.
    explanation: >-
      Confirms elevated gonadotropins and amenorrhoea as the recurrent endocrine
      outcome.
  downstream:
  - target: Premature Ovarian Insufficiency
    description: >-
      Loss of ovarian function before age 40 is the clinical definition of this
      outcome.
    causal_link_type: DIRECT
  - target: Hypergonadotropic Hypogonadism
    description: >-
      Loss of ovarian steroid and inhibin feedback raises pituitary
      gonadotropins.
    causal_link_type: DIRECT
  - target: Primary Amenorrhea
    description: >-
      When ovarian function was never established, menarche does not occur.
    causal_link_type: DIRECT
  - target: Secondary Amenorrhea
    description: >-
      When a reduced follicle pool is exhausted after menarche, menses cease.
    causal_link_type: DIRECT
  - target: Female Infertility
    description: >-
      Follicular depletion removes the oocytes required for conception.
    causal_link_type: DIRECT
  - target: Elevated Serum Follicle-Stimulating Hormone
    description: >-
      Release of the pituitary from ovarian negative feedback raises circulating
      FSH, the biochemical marker of the outcome.
    causal_link_type: DIRECT
  - target: Osteoporosis
    description: >-
      Prolonged oestrogen deficiency accelerates bone resorption and lowers bone
      mineral density, a preventable complication of untreated ovarian failure.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - Chronic hypo-oestrogenism releasing the brake on osteoclastic bone resorption

phenotypes:
- category: Auditory
  name: Bilateral Sensorineural Hearing Impairment
  description: >-
    Bilateral sensorineural hearing loss present in affected individuals of both
    sexes and required for the diagnosis. Severity ranges from profound with
    prelingual onset to moderate with early-childhood onset; middle-ear function
    is normal. Audiograms characteristically show steeply sloping high-frequency
    threshold elevation.
  phenotype_term:
    preferred_term: Sensorineural hearing impairment
    term:
      id: HP:0000407
      label: Sensorineural hearing impairment
  frequency: VERY_FREQUENT
  diagnostic: true
  evidence:
  - reference: PMID:42283975
    reference_title: "Comprehensive Insights into Perrault Syndrome: Genetic Diversity and Clinical Implications."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Perrault syndrome is a genetically and clinically diverse autosomal
      recessive disorder characterized by sensorineural hearing loss in both
      sexes and primary ovarian insufficiency in females.
    explanation: >-
      Sensorineural hearing loss is definitional and therefore present in
      essentially all affected individuals, supporting VERY_FREQUENT.
  phenotype_contexts:
  - sex: MALE
    notes: >-
      Hearing loss is fully expressed in 46,XY individuals, who typically have
      no gonadal phenotype and may therefore be classified as having
      nonsyndromic deafness.
    evidence:
    - reference: PMID:34338890
      reference_title: "New insights into Perrault syndrome, a clinically and genetically heterogeneous disorder."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        Perrault syndrome is inherited as an autosomal recessive disorder
        characterized by bilateral mild to severe childhood sensorineural
        hearing loss with variable age of onset in both sexes and ovarian
        dysfunction in females who have a 46, XX karyotype.
      explanation: Confirms hearing loss occurs in both sexes.
- category: Auditory
  name: Progressive Hearing Loss
  description: >-
    Hearing thresholds frequently deteriorate over time, so a mild or moderate
    initial loss can progress to severe or profound impairment and require
    escalation from hearing aids to cochlear implantation. Serial audiometry is
    therefore recommended after diagnosis.
  phenotype_term:
    preferred_term: Progressive sensorineural hearing impairment
    term:
      id: HP:0000408
      label: Progressive sensorineural hearing impairment
    clinical_course: PROGRESSIVE
  evidence:
  - reference: PMID:31827252
    reference_title: "A recurrent missense variant in HARS2 results in variable sensorineural hearing loss in three unrelated families."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Here, we report the variant HARS2 c.1439G>A p.(Arg480His) in three
      unrelated families with prelingual onset, bilateral symmetric progressive
      SNHL.
    explanation: Documents progressive bilateral sensorineural hearing loss.
- category: Auditory
  name: Auditory Neuropathy Pattern
  description: >-
    A retrocochlear or synaptic pattern in which otoacoustic emissions are
    preserved but auditory brainstem responses are absent, indicating a lesion
    at the inner hair cell synapse or cochlear nerve rather than at the outer
    hair cell. Documented in TWNK-related disease and detectable only if
    brainstem-response testing is performed, so it can be missed when hearing
    loss appears mild on pure-tone audiometry.
  phenotype_term:
    preferred_term: Abnormal auditory evoked potentials
    term:
      id: HP:0006958
      label: Abnormal auditory evoked potentials
  subtype: PRLTS5
  evidence:
  - reference: PMID:39340975
    reference_title: "Detailed characterization of auditory neuropathy in perrault syndrome with TWNK variants."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Maximum speech intelligibility score was 95 % with normal otoacoustic
      emission. However, no auditory brainstem responses were observed, leading
      to the diagnosis of auditory neuropathy.
    explanation: >-
      Documents the preserved-OAE, absent-ABR auditory neuropathy pattern in
      TWNK-related Perrault syndrome.
- category: Endocrine
  name: Premature Ovarian Insufficiency
  description: >-
    Loss of ovarian function before age 40 in individuals with a 46,XX
    karyotype, presenting as primary amenorrhoea with absent spontaneous puberty
    at the severe end or as secondary amenorrhoea after normal menarche at the
    milder end. This phenotype is sex-limited: 46,XY individuals with the same
    biallelic genotype generally have normal gonadal function.
  phenotype_term:
    preferred_term: Premature ovarian insufficiency
    term:
      id: HP:0008209
      label: Premature ovarian insufficiency
  frequency: VERY_FREQUENT
  diagnostic: true
  evidence:
  - reference: PMID:42283975
    reference_title: "Comprehensive Insights into Perrault Syndrome: Genetic Diversity and Clinical Implications."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Perrault syndrome is a genetically and clinically diverse autosomal
      recessive disorder characterized by sensorineural hearing loss in both
      sexes and primary ovarian insufficiency in females.
    explanation: >-
      Primary ovarian insufficiency is definitional in 46,XX individuals,
      supporting VERY_FREQUENT within that stratum.
  phenotype_contexts:
  - sex: FEMALE
    frequency: VERY_FREQUENT
    notes: >-
      Restricted to individuals with a 46,XX karyotype; essentially universal in
      postpubertal 46,XX individuals with a Perrault genotype.
    evidence:
    - reference: PMID:34338890
      reference_title: "New insights into Perrault syndrome, a clinically and genetically heterogeneous disorder."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        Perrault syndrome is inherited as an autosomal recessive disorder
        characterized by bilateral mild to severe childhood sensorineural
        hearing loss with variable age of onset in both sexes and ovarian
        dysfunction in females who have a 46, XX karyotype.
      explanation: >-
        Restricts the ovarian phenotype to the 46,XX karyotype stratum.
  - sex: MALE
    notes: >-
      Not expressed. 46,XY individuals with the same genotype have hearing loss
      with generally preserved gonadal function, which is why they present as
      apparently nonsyndromic deafness.
    evidence:
    - reference: PMID:31827252
      reference_title: "A recurrent missense variant in HARS2 results in variable sensorineural hearing loss in three unrelated families."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        All affected individuals are either male or prepubertal and as such
        would not present with POI, a cardinal feature of Perrault syndrome.
      explanation: >-
        Confirms that male carriers of a Perrault genotype do not manifest the
        ovarian phenotype.
- category: Endocrine
  name: Hypergonadotropic Hypogonadism
  description: >-
    Elevated FSH and LH with low oestradiol in 46,XX individuals, the endocrine
    signature that distinguishes the primary ovarian defect of Perrault syndrome
    from central (hypogonadotropic) causes of amenorrhoea.
  phenotype_term:
    preferred_term: Hypergonadotropic hypogonadism
    term:
      id: HP:0000815
      label: Hypergonadotropic hypogonadism
  evidence:
  - reference: PMID:32767731
    reference_title: "Perrault syndrome: Clinical report and retrospective analysis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The literature review showed that the phenotype for PRLTS4 varies widely,
      but the sensorineural hearing loss, increased gonadotropin levels, and
      amenorrhea occurred frequently.
    explanation: Documents elevated gonadotropins accompanying amenorrhoea.
- category: Endocrine
  name: Primary Amenorrhea
  description: >-
    Absence of menarche with absent or incomplete spontaneous pubertal
    development, seen at the severe end of the ovarian spectrum where germ cell
    loss is near-complete and the gonads are streak or absent.
  phenotype_term:
    preferred_term: Primary amenorrhea
    term:
      id: HP:0000786
      label: Primary amenorrhea
  evidence:
  - reference: PMID:32911714
    reference_title: "Two Novel Pathogenic Variants Confirm RMND1 Causative Role in Perrault Syndrome with Renal Involvement."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Evaluation for primary amenorrhea and delayed pubertal development at the
      age of 18 revealed gonadal dysgenesis with a normal female karyotype
      46,XX.
    explanation: >-
      Documents primary amenorrhoea with gonadal dysgenesis and a normal 46,XX
      karyotype in a genetically confirmed individual.
- category: Endocrine
  name: Secondary Amenorrhea
  description: >-
    Cessation of menses after apparently normal menarche and pubertal
    development, the presentation at the milder end of the ovarian spectrum
    where a reduced but functional follicle pool is exhausted prematurely.
  phenotype_term:
    preferred_term: Secondary amenorrhea
    term:
      id: HP:0000869
      label: Secondary amenorrhea
  evidence:
  - reference: PMID:31827252
    reference_title: "A recurrent missense variant in HARS2 results in variable sensorineural hearing loss in three unrelated families."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      They have a similar phenotype of profound SNHL with onset before 3 years
      of age and secondary amenorrhea presenting at 25 and 26 years of age,
      respectively.
    explanation: >-
      Documents secondary amenorrhoea as the ovarian presentation in two
      HARS2-related individuals.
- category: Reproductive
  name: Ovarian Dysgenesis with Streak Gonads
  description: >-
    Dysplastic, streak or absent ovaries reflecting near-complete loss of germ
    and supporting cells during ovarian development, at the developmental end of
    the ovarian phenotypic spectrum.
  phenotype_term:
    preferred_term: Streak ovary
    term:
      id: HP:0010464
      label: Streak ovary
  evidence:
  - reference: PMID:31827252
    reference_title: "A recurrent missense variant in HARS2 results in variable sensorineural hearing loss in three unrelated families."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Ovarian dysgenesis, with amenorrhea and streak gonads
    explanation: >-
      Records streak gonads with ovarian dysgenesis in a tabulated Perrault
      syndrome case.
- category: Reproductive
  name: Female Infertility
  description: >-
    Infertility in 46,XX individuals resulting from follicular depletion.
    Spontaneous conception is possible but unpredictable when residual ovarian
    reserve remains; oocyte or embryo cryopreservation is only feasible if
    performed before reserve is exhausted, and donor-oocyte IVF is the most
    reliable established option thereafter.
  phenotype_term:
    preferred_term: Female infertility
    term:
      id: HP:0008222
      label: Female infertility
  evidence:
  - reference: PMID:32911714
    reference_title: "Two Novel Pathogenic Variants Confirm RMND1 Causative Role in Perrault Syndrome with Renal Involvement."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Hypergonadotropic hypogonadism and small ovaries and uterus were
      recognized. Infertility was diagnosed, and hormone replacement therapy was
      introduced at the age of 28.
    explanation: >-
      Documents infertility as a consequence of the ovarian phenotype in a
      genetically confirmed individual.
- category: Neurologic
  name: Cerebellar Ataxia
  description: >-
    Progressive gait and limb ataxia, a defining feature of the type II
    neurological form. Essentially universal in TWNK-related disease and
    reported in HSD17B4-, LARS2- and HARS2-related disease.
  phenotype_term:
    preferred_term: Ataxia
    term:
      id: HP:0001251
      label: Ataxia
    clinical_course: PROGRESSIVE
  subtype: Type II
  evidence:
  - reference: PMID:31827252
    reference_title: "A recurrent missense variant in HARS2 results in variable sensorineural hearing loss in three unrelated families."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      In some cases of Perrault syndrome additional neurological features,
      including peripheral neuropathy, cerebellar ataxia, and intellectual
      disability have also been identified
    explanation: Documents cerebellar ataxia as a recognised feature.
- category: Neurologic
  name: Peripheral Axonal Neuropathy
  description: >-
    Length-dependent axonal sensorimotor neuropathy with distal weakness,
    sensory loss and hyporeflexia, contributing to gait impairment and falls in
    the type II form.
  phenotype_term:
    preferred_term: Peripheral axonal neuropathy
    term:
      id: HP:0003477
      label: Peripheral axonal neuropathy
  subtype: Type II
  evidence:
  - reference: PMID:25355836
    reference_title: "Mutations in Twinkle primase-helicase cause Perrault syndrome with neurologic features."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      To identify the genetic cause in 2 families of progressive ataxia, axonal
      neuropathy, hyporeflexia, and abnormal eye movements, accompanied by
      progressive hearing loss and ovarian dysgenesis, with a clinical diagnosis
      of Perrault syndrome.
    explanation: Documents axonal neuropathy in clinically diagnosed Perrault syndrome.
- category: Neurologic
  name: Hyporeflexia
  description: >-
    Reduced or absent deep tendon reflexes, a clinical sign of the peripheral
    axonal neuropathy of type II disease.
  phenotype_term:
    preferred_term: Hyporeflexia
    term:
      id: HP:0001265
      label: Hyporeflexia
  subtype: Type II
  evidence:
  - reference: PMID:25355836
    reference_title: "Mutations in Twinkle primase-helicase cause Perrault syndrome with neurologic features."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      To identify the genetic cause in 2 families of progressive ataxia, axonal
      neuropathy, hyporeflexia, and abnormal eye movements, accompanied by
      progressive hearing loss and ovarian dysgenesis, with a clinical diagnosis
      of Perrault syndrome.
    explanation: Documents hyporeflexia in the type II presentation.
- category: Neurologic
  name: Intellectual Disability
  description: >-
    Cognitive impairment reported in a minority of individuals, genotype
    dependent and part of the type II neurological spectrum.
  phenotype_term:
    preferred_term: Intellectual disability
    term:
      id: HP:0001249
      label: Intellectual disability
  subtype: Type II
  evidence:
  - reference: PMID:34338890
    reference_title: "New insights into Perrault syndrome, a clinically and genetically heterogeneous disorder."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      the phenotype of some subjects may additionally involve developmental
      delay, intellectual deficit and other neurological disabilities, which can
      vary in severity in part dependent upon the genetic variants and the gene
      involved
    explanation: >-
      Documents intellectual deficit in a subset, with genotype-dependent
      severity.
- category: Neurologic
  name: Global Developmental Delay
  description: >-
    Delayed attainment of motor, language and cognitive milestones in
    early-onset type II disease, particularly in PRORP- and DAP3-related
    presentations.
  phenotype_term:
    preferred_term: Global developmental delay
    term:
      id: HP:0001263
      label: Global developmental delay
  subtype: Type II
  evidence:
  - reference: PMID:34715011
    reference_title: "Bi-allelic variants in the mitochondrial RNase P subunit PRORP cause mitochondrial tRNA processing defects and pleiotropic multisystem presentations."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Affected individuals presented with variable phenotypes comprising
      sensorineural hearing loss, primary ovarian insufficiency, developmental
      delay, and brain white matter changes.
    explanation: Documents developmental delay in PRORP-related Perrault syndrome.
- category: Neurologic
  name: Cerebral White Matter Abnormality
  description: >-
    Abnormal cerebral white matter signal on MRI, ranging from limited
    white-matter change to frank leukodystrophy in severe LARS2- and
    PRORP-related disease.
  phenotype_term:
    preferred_term: Abnormal cerebral white matter morphology
    term:
      id: HP:0002500
      label: Abnormal cerebral white matter morphology
  subtype: Type II
  evidence:
  - reference: PMID:34715011
    reference_title: "Bi-allelic variants in the mitochondrial RNase P subunit PRORP cause mitochondrial tRNA processing defects and pleiotropic multisystem presentations."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Affected individuals presented with variable phenotypes comprising
      sensorineural hearing loss, primary ovarian insufficiency, developmental
      delay, and brain white matter changes.
    explanation: Documents brain white matter changes as part of the phenotype.
- category: Musculoskeletal
  name: Osteoporosis
  description: >-
    Reduced bone mineral density secondary to prolonged hypo-oestrogenism in
    46,XX individuals with untreated or late-treated ovarian insufficiency. It
    is a preventable complication rather than a primary manifestation, which is
    the rationale for oestrogen replacement continued to the usual age of
    menopause and for periodic bone-density surveillance.
  phenotype_term:
    preferred_term: Osteoporosis
    term:
      id: HP:0000939
      label: Osteoporosis
  evidence:
  - reference: PMID:32911714
    reference_title: "Two Novel Pathogenic Variants Confirm RMND1 Causative Role in Perrault Syndrome with Renal Involvement."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Vitamin B12 deficiency anemia and osteoporosis were diagnosed at the age
      of 26.
    explanation: >-
      Documents early-onset osteoporosis in a genetically confirmed individual
      with Perrault syndrome and ovarian insufficiency.
- category: Neurologic
  name: Abnormal Eye Movements
  description: >-
    Abnormal eye movements reported together with ataxia, axonal neuropathy and
    hyporeflexia in the type II neurological form, reflecting cerebellar and
    brainstem oculomotor involvement. Note that this is distinct from the
    ophthalmoparesis of the allelic dominant TWNK disorder PEOA3, which is not
    part of Perrault syndrome.
  phenotype_term:
    preferred_term: Abnormality of eye movement
    term:
      id: HP:0000496
      label: Abnormality of eye movement
  subtype: Type II
  evidence:
  - reference: PMID:25355836
    reference_title: "Mutations in Twinkle primase-helicase cause Perrault syndrome with neurologic features."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      To identify the genetic cause in 2 families of progressive ataxia, axonal
      neuropathy, hyporeflexia, and abnormal eye movements, accompanied by
      progressive hearing loss and ovarian dysgenesis, with a clinical diagnosis
      of Perrault syndrome.
    explanation: >-
      Lists abnormal eye movements among the neurological features of
      clinically diagnosed Perrault syndrome.
- category: Renal
  name: Chronic Kidney Disease
  description: >-
    Chronic kidney disease reported specifically in RMND1-related Perrault
    syndrome, where it accompanies hearing loss and ovarian dysfunction and
    represents a milder, organ-shifted expression of the RMND1 spectrum than
    classic combined oxidative phosphorylation deficiency 11.
  phenotype_term:
    preferred_term: Chronic kidney disease
    term:
      id: HP:0012622
      label: Chronic kidney disease
  evidence:
  - reference: PMID:32911714
    reference_title: "Two Novel Pathogenic Variants Confirm RMND1 Causative Role in Perrault Syndrome with Renal Involvement."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      We performed a thorough clinical investigation and applied a targeted
      multigene hearing loss panel to reveal the cause of hearing loss, ovarian
      dysfunction (two cardinal features of Perrault syndrome) and chronic
      kidney disease in two adult female siblings.
    explanation: >-
      Documents chronic kidney disease alongside the cardinal features in
      RMND1-related disease.
- category: Musculoskeletal
  name: Proximal Muscle Weakness
  description: >-
    Proximal weakness with dystrophic muscle histology, characteristic of
    GGPS1-related disease, which presents as a muscular dystrophy combined with
    congenital hearing loss and ovarian insufficiency.
  phenotype_term:
    preferred_term: Proximal muscle weakness
    term:
      id: HP:0003701
      label: Proximal muscle weakness
  evidence:
  - reference: PMID:32403198
    reference_title: "GGPS1 Mutations Cause Muscular Dystrophy/Hearing Loss/Ovarian Insufficiency Syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      In addition to proximal weakness, all but one patient presented with
      congenital sensorineural hearing loss, and all postpubertal females had
      primary ovarian insufficiency.
    explanation: >-
      Documents proximal weakness together with the cardinal Perrault features
      in the GGPS1 cohort.
- category: Reproductive
  name: Male Infertility
  description: >-
    Male reproductive impairment, including azoospermia and undervirilisation,
    is occasionally reported and is under-ascertained because affected 46,XY
    individuals are rarely investigated for it. Model-organism data are
    strongest for CLPP, where null mice show meiotic arrest and azoospermia. In
    contrast to the female phenotype, most 46,XY individuals with a Perrault
    genotype are fertile.
  phenotype_term:
    preferred_term: Male infertility
    term:
      id: HP:0003251
      label: Male infertility
  notes: >-
    Male infertility is a real but genotype-restricted and uncommon finding.
    A human CLPP case documents non-obstructive azoospermia, while CLPP-null
    mouse data provide mechanistic evidence for meiotic arrest. Do not
    generalise male infertility to Perrault syndrome as a whole.
  evidence:
  - reference: PMID:36611846
    reference_title: "CLPP Depletion Causes Diplotene Arrest; Underlying Testis Mitochondrial Dysfunction Occurs with Accumulation of Perrault Proteins ERAL1, PEO1, and HARS2."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Non-obstructive azoospermia (NOS, the complete absence of sperm from the
      ejaculate, due to a failure in spermatogenesis, leading to complete
      infertility) was observed so far in one of the few male individuals with
      a biallelic missense mutation in the gene encoding the mitochondrial
      matrix peptidase CLPP
    explanation: >-
      Documents a human CLPP-associated case of non-obstructive azoospermia,
      establishing direct clinical support while preserving its rarity and
      genotype restriction.
  - reference: PMID:36611846
    reference_title: "CLPP Depletion Causes Diplotene Arrest; Underlying Testis Mitochondrial Dysfunction Occurs with Accumulation of Perrault Proteins ERAL1, PEO1, and HARS2."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      No meiotic M-phase cells were detected. Proteome profiles identified
      strong deficits of proteins involved in male meiotic prophase (HSPA2,
      SHCBP1L, DMRT7, and HSF5), versus an accumulation of AURKAIP1.
    explanation: >-
      Documents late meiotic arrest in CLPP-null mouse testis, providing
      mechanistic model evidence for the genotype-restricted male infertility
      phenotype.

biochemical:
- name: Elevated Serum Follicle-Stimulating Hormone
  biomarker_term:
    preferred_term: Elevated circulating follicle stimulating hormone level
    term:
      id: HP:0008232
      label: Elevated circulating follicle stimulating hormone level
  presence: INCREASED
  notes: >-
    Raised serum FSH in 46,XX individuals is the biochemical hallmark of the
    primary ovarian defect and is what makes the hypogonadism
    hypergonadotropic. Repeated measurement of FSH with oestradiol, supported by
    anti-Mullerian hormone and antral follicle count, is the standard means of
    establishing premature ovarian insufficiency.
  evidence:
  - reference: PMID:36421788
    reference_title: "Integral Role of the Mitochondrial Ribosome in Supporting Ovarian Function: MRPS7 Variants in Syndromic Premature Ovarian Insufficiency."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      POI is a common cause of infertility, characterised by elevated
      follicle-stimulating hormone and amenorrhea in women under the age of 40.
    explanation: >-
      Defines elevated FSH with amenorrhoea as the diagnostic biochemical
      criterion for the ovarian phenotype.

genetic:
- name: LARS2
  gene_term:
    preferred_term: LARS2
    term:
      id: hgnc:17095
      label: LARS2
  relationship_type: CAUSATIVE
  subtype: PRLTS4
  notes: >-
    Mitochondrial leucyl-tRNA synthetase. The most frequent single cause in
    molecularly solved Perrault cohorts. Pathogenic variants reduce
    aminoacylation efficiency; severity tracks residual activity, with the
    mildest alleles giving isolated hearing loss and ovarian insufficiency and
    the most severe giving leukodystrophy or lethal infantile multisystem
    disease.
  case_fractions:
  - population: Molecularly diagnosed Perrault syndrome (GeneReviews overview cohort)
    case_fraction_percent: 21.0
    notes: >-
      Highest single-gene share among molecularly solved individuals in the
      GeneReviews Perrault Syndrome Overview gene table (PMID:25254289, full
      chapter). The PubMed abstract for that chapter is a scope summary and does
      not carry the table, so this figure is recorded without a
      snippet-quotable source.
  evidence:
  - reference: PMID:23541342
    reference_title: "Mutations in LARS2, encoding mitochondrial leucyl-tRNA synthetase, lead to premature ovarian failure and hearing loss in Perrault syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      In two families affected by POF accompanied by hearing loss (together,
      these symptoms compose Perrault syndrome), exome sequencing revealed
      mutations in LARS2, encoding mitochondrial leucyl-tRNA synthetase
    explanation: Establishes LARS2 causality.
  - reference: PMID:23541342
    reference_title: "Mutations in LARS2, encoding mitochondrial leucyl-tRNA synthetase, lead to premature ovarian failure and hearing loss in Perrault syndrome."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      Yeast complementation indicated that LARS2 c.1077delT is nonfunctional and
      that LARS2 p.Thr522Asn is partially functional.
    explanation: >-
      Functional evidence that pathogenic alleles are hypomorphic or null,
      supporting a loss-of-function mechanism.
- name: CLPP
  gene_term:
    preferred_term: CLPP
    term:
      id: hgnc:2084
      label: CLPP
  relationship_type: CAUSATIVE
  subtype: PRLTS3
  notes: >-
    Proteolytic subunit of the mitochondrial CLPXP protease and effector of the
    mitochondrial unfolded protein response. Perrault-associated substitutions
    cluster in a short region of the protein and are predicted to distort the
    proteolytic barrel chamber. GeneReviews places CLPP second by case share
    (about 18 per cent of solved cases).
  evidence:
  - reference: PMID:23541340
    reference_title: "Perrault syndrome is caused by recessive mutations in CLPP, encoding a mitochondrial ATP-dependent chambered protease."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      In each family, affected individuals were homozygous for a different
      pathogenic CLPP allele: c.433A>C (p.Thr145Pro), c.440G>C (p.Cys147Ser), or
      an experimentally demonstrated splice-donor-site mutation, c.270+4A>G.
    explanation: Establishes CLPP causality with three independent homozygous alleles.
- name: HARS2
  gene_term:
    preferred_term: HARS2
    term:
      id: hgnc:4817
      label: HARS2
  relationship_type: CAUSATIVE
  subtype: PRLTS2
  notes: >-
    Mitochondrial histidyl-tRNA synthetase. Genotypes typically combine a
    hypomorphic missense allele with a second hypomorphic or loss-of-function
    allele; biallelic loss of function has not been observed and is presumed
    lethal. A recurrent p.Arg480His allele has been reported in multiple
    unrelated families. GeneReviews places HARS2 third by case share (about 14
    per cent of solved cases).
  evidence:
  - reference: PMID:21464306
    reference_title: "Mutations in mitochondrial histidyl tRNA synthetase HARS2 cause ovarian dysgenesis and sensorineural hearing loss of Perrault syndrome."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      Aminoacylation activity of HARS2 p.V368L and HARS2 p.L200V was reduced and
      the deletion mutant was not stably expressed in mammalian mitochondria.
    explanation: >-
      Functional evidence that the pathogenic alleles reduce mitochondrial tRNA
      charging.
- name: HSD17B4
  gene_term:
    preferred_term: HSD17B4
    term:
      id: hgnc:5213
      label: HSD17B4
  relationship_type: CAUSATIVE
  subtype: PRLTS1
  notes: >-
    Peroxisomal D-bifunctional protein of fatty acid beta-oxidation, and the
    first Perrault syndrome gene identified. Allelic with D-bifunctional protein
    deficiency, a severe and usually fatal infantile peroxisomal disorder
    curated as a separate dismech entry; the Perrault presentation corresponds
    to hypomorphic genotypes with residual enzyme activity. Neurological
    features are characteristic of the reported HSD17B4 Perrault cases.
  evidence:
  - reference: PMID:20673864
    reference_title: "Mutations in the DBP-deficiency protein HSD17B4 cause ovarian dysgenesis, hearing loss, and ataxia of Perrault Syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      These results indicate that Perrault syndrome and DBP deficiency overlap
      clinically; that Perrault syndrome is genetically heterogeneous; that DBP
      deficiency may be underdiagnosed; and that whole-exome sequencing can
      reveal critical genes in small, nonconsanguineous families.
    explanation: >-
      Establishes HSD17B4 causality and the allelic relationship with
      D-bifunctional protein deficiency.
- name: TWNK
  gene_term:
    preferred_term: TWNK
    term:
      id: hgnc:1160
      label: TWNK
  relationship_type: CAUSATIVE
  subtype: PRLTS5
  notes: >-
    Twinkle mitochondrial DNA primase-helicase (formerly C10orf2). Biallelic
    variants cause Perrault syndrome, essentially always with neurological
    features. PLEIOTROPY WARNING — dominant missense variants in TWNK cause
    progressive external ophthalmoplegia type 3 (PEOA3, MONDO:0012241), and a
    distinct set of recessive variants causes mitochondrial DNA depletion
    syndrome 7 (infantile-onset spinocerebellar ataxia). Literature about the
    dominant PEO phenotype must not be imported into this recessive entry.
  evidence:
  - reference: PMID:25355836
    reference_title: "Mutations in Twinkle primase-helicase cause Perrault syndrome with neurologic features."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      In family 1, affected individuals were compound heterozygous for
      chromosome 10 open reading frame 2 (C10orf2) p.Arg391His and p.Asn585Ser.
    explanation: >-
      Documents biallelic (compound heterozygous) TWNK genotypes in Perrault
      syndrome, establishing the recessive mode for this phenotype.
  - reference: PMID:25355836
    reference_title: "Mutations in Twinkle primase-helicase cause Perrault syndrome with neurologic features."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The phenotypic heterogeneity of conditions caused by Twinkle mutations and
      the genetic heterogeneity of Perrault syndrome call for genomic definition
      of these disorders.
    explanation: >-
      Supports the need to keep the TWNK-associated phenotypes nosologically
      distinct rather than merged.
- name: PRORP
  gene_term:
    preferred_term: PRORP
    term:
      id: hgnc:19958
      label: PRORP
  relationship_type: CAUSATIVE
  notes: >-
    Metallonuclease subunit of mitochondrial RNase P (formerly KIAA0391),
    responsible for 5' end processing of mitochondrial precursor tRNAs. Not
    assigned a numbered PRLTS designation in MONDO or OMIM; presentations are
    multisystem and often include developmental delay and white-matter change.
  evidence:
  - reference: PMID:34715011
    reference_title: "Bi-allelic variants in the mitochondrial RNase P subunit PRORP cause mitochondrial tRNA processing defects and pleiotropic multisystem presentations."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      We report four unrelated families with multisystem disease associated with
      bi-allelic variants in PRORP, the metallonuclease subunit of mt-RNase P.
    explanation: Establishes PRORP causality in four independent families.
- name: GGPS1
  gene_term:
    preferred_term: GGPS1
    term:
      id: hgnc:4249
      label: GGPS1
  relationship_type: CAUSATIVE
  notes: >-
    Geranylgeranyl diphosphate synthase of the mevalonate/isoprenoid pathway.
    Biallelic variants cause a muscular dystrophy / hearing loss / ovarian
    insufficiency syndrome that overlaps Perrault syndrome; the mechanism is
    loss of protein prenylation rather than of mitochondrial gene expression.
    No numbered PRLTS designation.
  evidence:
  - reference: PMID:32403198
    reference_title: "GGPS1 Mutations Cause Muscular Dystrophy/Hearing Loss/Ovarian Insufficiency Syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      A total of 11 patients in 6 families carrying 5 different biallelic
      pathogenic variants in specific domains of GGPS1 were identified.
    explanation: Establishes GGPS1 causality across six families.
- name: ERAL1
  gene_term:
    preferred_term: ERAL1
    term:
      id: hgnc:3424
      label: ERAL1
  relationship_type: CAUSATIVE
  subtype: PRLTS6
  notes: >-
    GTPase chaperone that binds mitochondrial 12S rRNA and is required for
    assembly of the small mitoribosomal subunit. An uncommon cause, at about 2
    per cent of solved cases in the GeneReviews gene table.
  evidence:
  - reference: PMID:28449065
    reference_title: "A homozygous missense mutation in ERAL1, encoding a mitochondrial rRNA chaperone, causes Perrault syndrome."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      Moreover, levels of the 12S rRNA were reduced in the patients, and were
      rescued by lentiviral expression of wild type ERAL1.
    explanation: >-
      Rescue experiment confirming that the ERAL1 variant causes the molecular
      phenotype.
- name: RMND1
  gene_term:
    preferred_term: RMND1
    term:
      id: hgnc:21176
      label: RMND1
  relationship_type: CAUSATIVE
  notes: >-
    Mitochondrial inner-membrane factor that tethers mitoribosomes near sites of
    transcript maturation, supporting translation of mtDNA-encoded polypeptides.
    Allelic with combined oxidative phosphorylation deficiency 11; the Perrault
    presentation is the mild end of that spectrum and is distinguished by
    chronic kidney disease with little or no neurological involvement. No
    numbered PRLTS designation.
  evidence:
  - reference: PMID:32911714
    reference_title: "Two Novel Pathogenic Variants Confirm RMND1 Causative Role in Perrault Syndrome with Renal Involvement."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Our study presents the mildest, so far reported, RMND1-related phenotype
      and delivers the first independent confirmation that RMND1 is causally
      involved in the development of Perrault syndrome with renal involvement.
    explanation: >-
      Provides the independent confirmation establishing RMND1 as a Perrault
      syndrome gene.
- name: DAP3
  gene_term:
    preferred_term: DAP3
    term:
      id: hgnc:2673
      label: DAP3
  relationship_type: CAUSATIVE
  subtype: PRLTS7
  notes: >-
    Encodes mitoribosomal small subunit protein 29 (MRPS29). Biallelic variants
    reduce small subunit assembly and cause combined complex I and IV
    deficiency, with presentations spanning Perrault syndrome to a severe
    neurometabolic phenotype.
  evidence:
  - reference: PMID:39371131
    reference_title: "Biallelic variants in DAP3 result in reduced assembly of the mitoribosomal small subunit with altered intrinsic and extrinsic apoptosis and a Perrault syndrome-spectrum phenotype."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      Lentiviral transduction of fibroblasts from affected individuals with
      wild-type DAP3 cDNA increased DAP3 mRNA expression, and partially rescued
      protein levels of MRPS7, MRPS9 and complex I and IV subunits,
      demonstrating the pathogenicity of the DAP3 variants.
    explanation: Rescue experiment demonstrating DAP3 variant pathogenicity.
- name: MRPS7
  gene_term:
    preferred_term: MRPS7
    term:
      id: hgnc:14499
      label: MRPS7
  relationship_type: CAUSATIVE
  notes: >-
    Mitoribosomal small subunit protein. Reported in two independent families
    with syndromic premature ovarian insufficiency and sensorineural hearing
    loss; no numbered PRLTS designation.
  evidence:
  - reference: PMID:36421788
    reference_title: "Integral Role of the Mitochondrial Ribosome in Supporting Ovarian Function: MRPS7 Variants in Syndromic Premature Ovarian Insufficiency."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      This second independent report validates that variants in MRPS7 are a
      cause of syndromic POI/Perrault syndrome.
    explanation: >-
      Provides the second independent report establishing MRPS7 as a Perrault
      syndrome gene.
- name: TFAM
  gene_term:
    preferred_term: TFAM
    term:
      id: hgnc:11741
      label: TFAM
  relationship_type: UNKNOWN
  notes: >-
    Mitochondrial transcription factor A, required for mtDNA transcription,
    replication and nucleoid packaging. Deliberately curated at a LOWER evidence
    tier than the other genes in this section. Tucker et al. 2020 name TFAM
    among "candidate genes" in patients who remained unsolved after the
    confirmed diagnoses, whereas the same paper states positively that PEX6
    variants "can present clinically as Perrault syndrome" with supporting
    serum biochemistry. TFAM is therefore mechanistically plausible - it sits in
    the same mtDNA-maintenance arm as TWNK - and is listed among Perrault genes
    by review articles, but it has not been established with the segregation and
    functional evidence available for the numbered subtypes, and it carries no
    PRLTS designation. relationship_type is UNKNOWN rather than CAUSATIVE to
    record that distinction rather than flatten it. MRPL49 and MRPL50, which
    appear in the same review gene list, are omitted for the same reason and
    with less supporting evidence still.
  evidence:
  - reference: PMID:32399598
    reference_title: "Genomic sequencing highlights the diverse molecular causes of Perrault syndrome: a peroxisomal disorder (PEX6), metabolic disorders (CLPP, GGPS1), and mtDNA maintenance/translation disorders (LARS2, TFAM)."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The remaining patients had variants in candidate genes such as TFAM,
      involved in mtDNA transcription, replication, and packaging, and GGPS1
      involved in mevalonate/coenzyme Q10 biosynthesis and whose enzymatic
      product is required for mouse folliculogenesis.
    explanation: >-
      The source explicitly frames TFAM as a candidate gene rather than an
      established cause, which is why this entry is marked PARTIAL and the
      relationship_type is UNKNOWN.
- name: PEX6
  gene_term:
    preferred_term: PEX6
    term:
      id: hgnc:8859
      label: PEX6
  relationship_type: CAUSATIVE
  notes: >-
    Peroxisome biogenesis factor. Allelic with Zellweger-spectrum peroxisome
    biogenesis disorder, curated separately; hypomorphic genotypes can present
    clinically as Perrault syndrome with demonstrable peroxisomal dysfunction.
    A rare cause, at about 1 per cent of solved cases. No numbered PRLTS
    designation.
  evidence:
  - reference: PMID:32399598
    reference_title: "Genomic sequencing highlights the diverse molecular causes of Perrault syndrome: a peroxisomal disorder (PEX6), metabolic disorders (CLPP, GGPS1), and mtDNA maintenance/translation disorders (LARS2, TFAM)."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      For the first time, we show that pathogenic variants in PEX6 can present
      clinically as Perrault syndrome.
    explanation: Establishes PEX6 as a molecular cause of the Perrault phenotype.

prevalence:
- population: Worldwide
  measure_type: POINT_PREVALENCE
  prevalence_class: ULTRA_RARE
  notes: >-
    No reliable population-based prevalence, incidence or carrier frequency has
    been established. Perrault syndrome is consistently described as rare, with
    published cases numbering in the low hundreds and drawn from selectively
    ascertained deafness and premature-ovarian-insufficiency clinics.
    Under-ascertainment in 46,XY individuals, who lack the gonadal phenotype,
    means any published figure is a lower bound.
  evidence:
  - reference: PMID:42283975
    reference_title: "Comprehensive Insights into Perrault Syndrome: Genetic Diversity and Clinical Implications."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The cohort demonstrates a distribution of 56.1% homozygous and 43.9%
      compound heterozygous variants, reflecting diverse ancestral backgrounds
      and potential selective pressures against deleterious alleles.
    explanation: >-
      The largest synthesis available reports only aggregate genotype
      proportions across a literature cohort, with no population denominator,
      supporting the assessment that prevalence is unquantified and the disorder
      ultra-rare.

diagnosis:
- name: Pure-Tone Audiometry with Auditory Brainstem Response
  description: >-
    Comprehensive audiological assessment including pure-tone audiometry,
    tympanometry, otoacoustic emissions, acoustic reflexes and auditory
    brainstem responses. Brainstem-response testing is essential because a
    subset of individuals, particularly those with TWNK variants, have an
    auditory-neuropathy pattern that pure-tone audiometry alone will
    underestimate. Serial testing is required because hearing loss is often
    progressive and can be late-onset.
  evidence:
  - reference: PMID:39340975
    reference_title: "Detailed characterization of auditory neuropathy in perrault syndrome with TWNK variants."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      These cases highlight the importance of detailed hearing tests, including
      auditory brainstem response and genetic tests in patients with Perrault
      syndrome, even in cases of mild hearing loss, for accurate diagnosis and
      appropriate management.
    explanation: >-
      Directly recommends auditory brainstem response testing in suspected
      Perrault syndrome.
- name: Comprehensive Genomic Sequencing
  description: >-
    Because the disorder is caused by at least fifteen genes and known genes
    explain only about half of clinically diagnosed individuals, a comprehensive
    hearing-loss / premature-ovarian-insufficiency / mitochondrial gene panel or
    exome/genome sequencing with copy-number analysis is the appropriate
    first-line molecular test. Karyotype and FMR1 premutation testing remain
    part of the wider evaluation of premature ovarian insufficiency to exclude
    the principal non-Perrault causes.
  evidence:
  - reference: PMID:34338890
    reference_title: "New insights into Perrault syndrome, a clinically and genetically heterogeneous disorder."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Variants of these eight genes only account for approximately half of the
      individuals with clinical features of Perrault syndrome where the
      molecular genetic base remains under investigation.
    explanation: >-
      Establishes the incomplete diagnostic yield that motivates broad genomic
      rather than targeted testing.

treatments:
- name: Hearing Aids and Auditory Rehabilitation
  description: >-
    Amplification for aidable hearing loss with speech and language therapy and
    educational support, fitted early to protect language and cognitive
    development. Frequently escalated to cochlear implantation as hearing loss
    progresses. Ototoxic medication, in particular aminoglycosides where an
    alternative exists, and loud-noise exposure should be avoided in individuals
    with an already vulnerable cochlea.
  therapeutic_modality: DEVICE
  treatment_term:
    preferred_term: Rehabilitation
    term:
      id: NCIT:C15315
      label: Rehabilitation
  target_mechanisms:
  - target: Sensorineural Hearing Loss
    treatment_effect: BYPASSES
    description: >-
      Amplification compensates for the reduced cochlear output without
      correcting the underlying hair cell injury.
  evidence:
  - reference: PMID:32911714
    reference_title: "Two Novel Pathogenic Variants Confirm RMND1 Causative Role in Perrault Syndrome with Renal Involvement."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      She received hearing aids at the age of six; the degree of HL progressed
      gradually and was accompanied by tinnitus and vertigo from the age of 31.
    explanation: >-
      Documents hearing aid use, and its eventual insufficiency, in a
      genetically confirmed individual.
- name: Cochlear Implantation
  description: >-
    Surgical implantation of a cochlear implant for severe-to-profound
    sensorineural hearing loss not adequately served by amplification. Outcomes
    reported in genetically confirmed Perrault syndrome have been good,
    including in adults implanted after decades of progressive loss.
  therapeutic_modality: DEVICE
  treatment_term:
    preferred_term: cochlear device implantation
    term:
      id: NCIT:C15329
      label: Surgical Procedure
  target_mechanisms:
  - target: Cochlear Hair Cell Mitochondrial Injury and Loss
    treatment_effect: BYPASSES
    description: >-
      Direct electrical stimulation of the cochlear nerve bypasses the lost or
      dysfunctional hair cells entirely.
  evidence:
  - reference: PMID:32911714
    reference_title: "Two Novel Pathogenic Variants Confirm RMND1 Causative Role in Perrault Syndrome with Renal Involvement."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Cochlear implantation was performed for the right ear at the age of 34 and
      for the left ear at the age of 36 with a good outcome.
    explanation: >-
      Documents successful cochlear implantation in genetically confirmed
      Perrault syndrome.
- name: Oestrogen and Progestogen Replacement Therapy
  description: >-
    Hormone replacement in 46,XX individuals, using incremental oestrogen to
    induce puberty when required, followed by cyclic oestrogen with a
    progestogen if the uterus is present. Replacement is continued to the usual
    age of menopause to limit the bone, cardiovascular and urogenital
    consequences of prolonged hypo-oestrogenism. This treats the downstream
    hormone deficiency; it does not restore ovarian reserve.
  therapeutic_modality: SMALL_MOLECULE
  treatment_term:
    preferred_term: Hormone Replacement Therapy
    term:
      id: NCIT:C15599
      label: Hormone Replacement Therapy
    therapeutic_agent:
    - preferred_term: oestradiol
      term:
        id: CHEBI:16469
        label: 17beta-estradiol
    - preferred_term: dydrogesterone
      term:
        id: CHEBI:31527
        label: dydrogesterone
  target_mechanisms:
  - target: Hypergonadotropic Ovarian Failure
    treatment_effect: BYPASSES
    description: >-
      Exogenous oestrogen and progestogen replace the missing ovarian steroid
      output, correcting the downstream hypo-oestrogenic state without
      restoring follicular function.
  evidence:
  - reference: PMID:32911714
    reference_title: "Two Novel Pathogenic Variants Confirm RMND1 Causative Role in Perrault Syndrome with Renal Involvement."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Both receive oestradiol and dydrogesterone supplementation to reduce the
      complications of POI.
    explanation: >-
      Documents combined oestrogen and progestogen replacement given
      specifically to reduce the complications of premature ovarian
      insufficiency.
- name: Assisted Reproduction with Donor Oocytes
  description: >-
    Donor-oocyte in vitro fertilisation is the most reliable fertility option
    once the follicle pool is exhausted. Oocyte or embryo cryopreservation may
    be considered while residual ovarian reserve remains, which requires
    diagnosis and counselling before reserve is lost — an argument for
    prepubertal surveillance of girls with unexplained bilateral sensorineural
    hearing loss.
  therapeutic_modality: OTHER
  treatment_term:
    preferred_term: Assisted Reproductive Technology
    term:
      id: NCIT:C93282
      label: Assisted Reproductive Technology
  target_mechanisms:
  - target: Female Infertility
    treatment_effect: BYPASSES
    description: >-
      Donor oocytes bypass the depleted follicle pool without restoring ovarian
      function.
  evidence:
  - reference: PMID:36421788
    reference_title: "Integral Role of the Mitochondrial Ribosome in Supporting Ovarian Function: MRPS7 Variants in Syndromic Premature Ovarian Insufficiency."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      POI is a common cause of infertility, characterised by elevated
      follicle-stimulating hormone and amenorrhea in women under the age of 40.
    explanation: >-
      Establishes the infertility that assisted reproduction addresses; the
      specific donor-oocyte recommendation derives from clinical management
      guidance rather than this report, so support is marked PARTIAL.
- name: Genetic Counselling
  description: >-
    Counselling for the 25 per cent sibling recurrence risk of an autosomal
    recessive disorder, with cascade testing of at-risk relatives. Counselling
    must address the sex-limited expression explicitly: a 46,XY sibling
    inheriting both alleles is at risk of hearing loss but generally not of
    gonadal disease, and a 46,XX sibling should be offered pubertal and
    ovarian-reserve surveillance before reproductive decisions are needed.
    Preimplantation or prenatal testing is available once familial variants are
    known.
  therapeutic_modality: BEHAVIORAL
  treatment_term:
    preferred_term: Genetic Counseling
    term:
      id: NCIT:C15240
      label: Genetic Counseling
  evidence:
  - reference: PMID:34338890
    reference_title: "New insights into Perrault syndrome, a clinically and genetically heterogeneous disorder."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Perrault syndrome is inherited as an autosomal recessive disorder
      characterized by bilateral mild to severe childhood sensorineural hearing
      loss with variable age of onset in both sexes and ovarian dysfunction in
      females who have a 46, XX karyotype.
    explanation: >-
      Establishes the recessive inheritance and sex-limited expression that
      determine the content of counselling.

differential_diagnoses:
- name: 46,XX gonadal dysgenesis
  disease_term:
    preferred_term: 46,XX gonadal dysgenesis
    term:
      id: MONDO:0009299
      label: 46 XX gonadal dysgenesis
  description: >-
    The closest ovarian-side boundary and the most important one to draw
    correctly. Both present with hypergonadotropic ovarian failure in a 46,XX
    individual, and the dismech entry for 46,XX gonadal dysgenesis already lists
    Perrault syndrome as a differential; the two entries are deliberately kept
    separate rather than merged.
  distinguishing_features:
  - Sensorineural hearing loss is required for Perrault syndrome and is absent in isolated 46,XX gonadal dysgenesis.
  - 46,XX gonadal dysgenesis is confined to the gonad; Perrault syndrome is a multisystem mitochondrial disorder that may add ataxia, neuropathy, renal or muscular disease.
  - The numbered ovarian-dysgenesis gene series is distinct from the Perrault gene set, and NR5A1-related disease belongs with neither.
  - Male relatives are unaffected in 46,XX gonadal dysgenesis but have hearing loss in Perrault syndrome, so a deaf brother is a strong pointer to Perrault syndrome.
  evidence:
  - reference: PMID:34338890
    reference_title: "New insights into Perrault syndrome, a clinically and genetically heterogeneous disorder."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Perrault syndrome is inherited as an autosomal recessive disorder
      characterized by bilateral mild to severe childhood sensorineural hearing
      loss with variable age of onset in both sexes and ovarian dysfunction in
      females who have a 46, XX karyotype.
    explanation: >-
      The obligatory bilateral hearing loss in both sexes is the discriminating
      feature against isolated 46,XX gonadal dysgenesis.
- name: Turner syndrome
  disease_term:
    preferred_term: Turner syndrome
    term:
      id: MONDO:0019499
      label: Turner syndrome
  description: >-
    The commonest cause of hypergonadotropic ovarian failure and a genuine
    mimic, because a majority of adults with Turner syndrome also develop
    progressive high-tone sensorineural hearing loss, reproducing both cardinal
    Perrault features in one individual.
  distinguishing_features:
  - Karyotype is 45,X or a structural X abnormality, not 46,XX; karyotype or chromosomal microarray settles the distinction.
  - Short stature, lymphoedema, webbed neck, coarctation and bicuspid aortic valve are Turner features not seen in Perrault syndrome.
  - Turner syndrome is a chromosomal disorder and is generally sporadic; Perrault syndrome is autosomal recessive with a 25 per cent sibling recurrence risk.
  - Male relatives cannot be affected in Turner syndrome, whereas Perrault syndrome affects 46,XY relatives with hearing loss.
  evidence:
  - reference: PMID:42283975
    reference_title: "Comprehensive Insights into Perrault Syndrome: Genetic Diversity and Clinical Implications."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Perrault syndrome is a genetically and clinically diverse autosomal
      recessive disorder characterized by sensorineural hearing loss in both
      sexes and primary ovarian insufficiency in females.
    explanation: >-
      Establishes the autosomal recessive, both-sexes character that separates
      Perrault syndrome from a sex-chromosome aneuploidy.
- name: FMR1 premutation-associated primary ovarian insufficiency
  disease_term:
    preferred_term: premature ovarian failure 1
    term:
      id: MONDO:0010706
      label: premature ovarian failure 1
  description: >-
    The commonest single-gene cause of premature ovarian insufficiency and a
    mandatory exclusion in any woman presenting with it, including one being
    evaluated for Perrault syndrome.
  distinguishing_features:
  - Caused by an FMR1 CGG repeat premutation, detected by targeted repeat sizing rather than sequencing, so a negative gene panel does not exclude it.
  - X-linked transmission with premutation carriers in the maternal line, not autosomal recessive.
  - Sensorineural hearing loss is not a feature; associated findings are fragile X-associated tremor/ataxia syndrome in older carriers and fragile X syndrome in expanded offspring.
  evidence:
  - reference: PMID:34338890
    reference_title: "New insights into Perrault syndrome, a clinically and genetically heterogeneous disorder."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Hearing loss and impaired fertility are common human disorders each with
      multiple genetic causes.
    explanation: >-
      Frames the central diagnostic problem — each cardinal feature is
      independently common — which is why the principal isolated causes of
      premature ovarian insufficiency such as the FMR1 premutation must be
      excluded before invoking a single recessive syndrome.
- name: Autoimmune polyendocrine syndrome type 1
  disease_term:
    preferred_term: autoimmune polyendocrine syndrome type 1
    term:
      id: MONDO:0009411
      label: autoimmune polyendocrine syndrome type 1
  description: >-
    The principal autoimmune cause of premature ovarian insufficiency, caused by
    biallelic AIRE variants. Like Perrault syndrome it is recessive and
    multisystem, so it is not excluded by inheritance pattern alone.
  distinguishing_features:
  - Chronic mucocutaneous candidiasis and hypoparathyroidism with adrenal insufficiency form the defining triad; none occurs in Perrault syndrome.
  - Ovarian failure is autoimmune, with detectable steroid-cell and 21-hydroxylase autoantibodies, rather than a primary germ-cell energetic defect.
  - Sensorineural hearing loss is not a feature.
  evidence:
  - reference: PMID:36421788
    reference_title: "Integral Role of the Mitochondrial Ribosome in Supporting Ovarian Function: MRPS7 Variants in Syndromic Premature Ovarian Insufficiency."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Here we describe a patient with POI, sensorineural hearing loss and
      Hashimoto's disease. The co-occurrence of POI with sensorineural hearing
      loss indicates Perrault syndrome.
    explanation: >-
      Illustrates the diagnostic trap directly: coexisting autoimmune
      endocrinopathy can suggest an autoimmune cause, yet the hearing-loss plus
      ovarian-insufficiency combination still indicated Perrault syndrome on
      molecular testing.
- name: Usher syndrome
  disease_term:
    preferred_term: Usher syndrome
    term:
      id: MONDO:0019501
      label: Usher syndrome
  description: >-
    The commonest syndromic form of recessive sensorineural hearing loss and
    therefore a routine alternative when a deaf proband is investigated,
    particularly before any ovarian phenotype has declared itself.
  distinguishing_features:
  - Progressive retinitis pigmentosa with night blindness and visual field loss is the defining second feature; retinal disease is not part of Perrault syndrome.
  - Vestibular areflexia is characteristic of Usher type 1 and is not a Perrault feature.
  - Gonadal function is normal in Usher syndrome, so ovarian assessment discriminates once a 46,XX proband reaches puberty.
  evidence:
  - reference: PMID:31827252
    reference_title: "A recurrent missense variant in HARS2 results in variable sensorineural hearing loss in three unrelated families."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      In the families reported here a diagnosis of SNHL revealed variants in a
      Perrault syndrome related gene, which would not have been suspected based
      on clinical presentation alone.
    explanation: >-
      Shows that Perrault genotypes are found among probands ascertained purely
      as hearing loss, the population in which syndromic deafness alternatives
      such as Usher syndrome are the working differential.
- name: D-bifunctional protein deficiency
  disease_term:
    preferred_term: d-bifunctional protein deficiency
    term:
      id: MONDO:0009855
      label: d-bifunctional protein deficiency
  description: >-
    An allelic disorder rather than an unrelated mimic: severe biallelic
    HSD17B4 variants cause D-bifunctional protein deficiency while hypomorphic
    variants in the same gene cause Perrault syndrome. Curated as a separate
    dismech entry; the relationship is one of allelic severity, not of
    coincidental resemblance.
  distinguishing_features:
  - Neonatal hypotonia, intractable seizures and failure to thrive with death usually within the first two years, versus a chronic disorder compatible with normal lifespan.
  - Elevated very-long-chain fatty acids are consistently abnormal in D-bifunctional protein deficiency and may be normal or only mildly abnormal in HSD17B4 Perrault syndrome.
  - No female with D-bifunctional protein deficiency has survived past puberty, so the ovarian phenotype cannot be assessed in that disorder.
  evidence:
  - reference: PMID:20673864
    reference_title: "Mutations in the DBP-deficiency protein HSD17B4 cause ovarian dysgenesis, hearing loss, and ataxia of Perrault Syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Mutations in HSD17B4 are known to cause DBP deficiency, an
      autosomal-recessive disorder of peroxisomal fatty acid beta-oxidation that
      is generally fatal within the first two years of life. No females with DBP
      deficiency surviving past puberty have been reported, and ovarian
      dysgenesis has not previously been associated with this illness.
    explanation: >-
      Documents both the allelic relationship and the clinical features that
      separate the two HSD17B4 phenotypes.
- name: Autosomal dominant progressive external ophthalmoplegia type 3
  disease_term:
    preferred_term: progressive external ophthalmoplegia with mitochondrial DNA deletions, autosomal dominant 3
    term:
      id: MONDO:0012241
      label: progressive external ophthalmoplegia with mitochondrial DNA deletions, autosomal dominant 3
  description: >-
    The TWNK allelic boundary, and the most important nosological trap in this
    entry. The same gene that causes Perrault syndrome 5 when biallelic
    hypomorphic variants are present also causes autosomal DOMINANT progressive
    external ophthalmoplegia type 3, and, with a different set of recessive
    variants, mitochondrial DNA depletion syndrome 7. These are separate
    disorders and their literature must not be imported into the Perrault entry.
  distinguishing_features:
  - Inheritance is autosomal DOMINANT with a single heterozygous missense variant; Perrault syndrome 5 requires two variants in trans.
  - Ptosis and progressive ophthalmoparesis are the presenting features; ophthalmoplegia is not a cardinal Perrault feature.
  - Ovarian insufficiency in a 46,XX individual, the defining sex-limited Perrault feature, is not part of the PEOA3 phenotype.
  - The third TWNK phenotype, mitochondrial DNA depletion syndrome 7, presents as infantile-onset spinocerebellar ataxia with epilepsy rather than as hearing loss with ovarian insufficiency.
  evidence:
  - reference: PMID:25355836
    reference_title: "Mutations in Twinkle primase-helicase cause Perrault syndrome with neurologic features."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Twinkle is known also to harbor multiple mutations, nearly all missenses,
      leading to dominant progressive external ophthalmoplegia type 3 and to
      recessive mitochondrial DNA depletion syndrome 7, also known as
      infantile-onset spinocerebellar ataxia.
    explanation: >-
      Explicitly separates the dominant PEO and mtDNA-depletion phenotypes from
      the recessive Perrault presentation of the same gene.

references:
- reference: PMID:25254289
  title: "Perrault Syndrome Overview."
  tags:
  - GeneReviews
- reference: PMID:34338890
  title: "New insights into Perrault syndrome, a clinically and genetically heterogeneous disorder."
- reference: PMID:42283975
  title: "Comprehensive Insights into Perrault Syndrome: Genetic Diversity and Clinical Implications."

📚

References & Deep Research

References

3

PMID:25254289

Perrault Syndrome Overview.

No top-level findings curated for this source.

PMID:34338890

New insights into Perrault syndrome, a clinically and genetically heterogeneous disorder.

No top-level findings curated for this source.

PMID:42283975

Comprehensive Insights into Perrault Syndrome: Genetic Diversity and Clinical Implications.

No top-level findings curated for this source.

Deep Research

1

Falcon ▸

Perrault Syndrome: Disease-Characteristics Research Report

Edison Scientific Literature 30 citations 2026-08-01T05:22:07.035063

Perrault Syndrome: Disease-Characteristics Research Report

Executive summary

Perrault syndrome is a rare, clinically and genetically heterogeneous autosomal-recessive, sex-influenced Mendelian disorder. Its defining manifestations are bilateral sensorineural hearing loss (SNHL) in 46,XX and 46,XY individuals and hypergonadotropic ovarian insufficiency/dysgenesis in 46,XX individuals. Hearing loss ranges from congenital severe/profound disease to milder adult-onset loss; ovarian disease ranges from secondary amenorrhea to absent/streak ovaries, failed puberty, and primary amenorrhea. Neurologic, renal, growth, muscular, and other mitochondrial-system manifestations occur variably. The literature commonly distinguishes type 1 disease without neurologic involvement from type 2 disease with neurologic manifestations, but these clinical categories must not be confused with numbered OMIM molecular subtypes. (faridi2022newinsightsinto pages 1-3, kline2022integralroleof pages 1-2)

The best-supported 2022 core genes were CLPP, ERAL1, GGPS1, HARS2, HSD17B4, LARS2, RMND1, and TWNK. Depending on cohort definition, these explained only approximately 40–50% of clinically diagnosed cases. More recent work supports an expanded mitochondrial/peroxisomal spectrum involving PRORP, TFAM, PEX6, MRPS7, MRPL50, and—reported online in December 2024—DAP3/MRPS29. These expanded associations are not all equally curated and should not automatically be treated as equivalent to the core eight-gene set. (faridi2022newinsightsinto pages 1-3, kline2022integralroleof pages 1-2, smith2025biallelicvariantsin pages 1-2)

No disease-modifying treatment, approved targeted therapy, validated preventive medication, or Perrault-specific interventional trial was identified. Current implementation is multidisciplinary and supportive: hearing aids or cochlear implantation, estrogen/progestogen replacement when indicated, bone and cardiovascular protection, fertility counseling/assisted reproduction, rehabilitation, and genotype-directed neurologic, renal, hepatic, cardiac, and metabolic surveillance. (faridi2022newinsightsinto pages 11-13, oziebło2020twonovelpathogenic pages 1-3)

1. Disease information

Definition and terminology

Perrault syndrome is also called ovarian dysgenesis with sensorineural deafness, XX gonadal dysgenesis with deafness, or hearing loss–ovarian insufficiency syndrome. The defining association is not merely infertility plus deafness: in 46,XX individuals, laboratory evidence generally demonstrates hypergonadotropic hypogonadism, reflecting primary ovarian rather than hypothalamic/pituitary failure. A succinct exact statement from Faridi et al. is: “Perrault syndrome is inherited as an autosomal recessive disorder characterized by bilateral mild to severe childhood sensorineural hearing loss with variable age of onset in both sexes and ovarian dysfunction in females who have a 46, XX karyotype.” (faridi2022newinsightsinto pages 1-3)

Identifiers

MONDO: MONDO:0017312 (Perrault syndrome). Open Targets maps this entity to 12 associated targets, while retaining separate molecular subtype entries. (OpenTargets Search: Perrault syndrome)
OMIM clinical/molecular series: commonly cited entries include PRLTS1 #233400, PRLTS2 #614926, PRLTS4 #615300, PRLTS5 #616138, and PRLTS6 #617565. The numbered subtype scheme is gene-based and is distinct from clinical “type 1/type 2” classification. (faridi2022newinsightsinto pages 1-3, forli2021ararecase pages 1-2)
Orphanet: an Orphanet disease record exists, but its precise ORPHA number was not verified in the retrieved primary-text evidence and should be checked directly against the current Orphanet nomenclature release before database ingestion.
ICD-10/ICD-11: no highly specific Perrault syndrome code was established in the retrieved evidence. Real-world coding generally requires component codes for congenital/hereditary SNHL, primary ovarian insufficiency/gonadal dysgenesis, and the relevant genetic syndrome.
MeSH: no dedicated MeSH descriptor was verified; indexing commonly uses Sensorineural Hearing Loss, Primary Ovarian Insufficiency, Gonadal Dysgenesis, and mitochondrial/peroxisomal disease terms.

Evidence provenance

The syndrome-level definition and gene lists are aggregated disease-level knowledge synthesized from literature and databases. Most frequencies and genotype–phenotype observations, however, derive from individual pedigrees, case reports, small case series, and sequencing cohorts—not EHR-scale population studies. Accordingly, ascertainment and publication bias are substantial.

2. Etiology, risk, protective factors, and gene–environment interaction

Primary cause

The primary cause is biallelic germline pathogenic or likely pathogenic variation in genes governing mitochondrial translation, mitoribosome assembly, mitochondrial RNA processing, mtDNA maintenance, mitochondrial proteostasis/metabolism, or peroxisomal function. Somatic causation is not characteristic. (faridi2022newinsightsinto pages 1-3, kline2022integralroleof pages 1-2)

Genetic risk factors

An affected individual usually inherits one pathogenic allele from each heterozygous parent.
Consanguinity increases the probability that both parents carry the same rare pathogenic allele and is represented in several reported families, but is not necessary; compound-heterozygous disease is well documented. (hochberg2021biallelicvariantsin pages 1-2, oziebło2020twonovelpathogenic pages 1-3)
For two carrier parents, standard autosomal-recessive recurrence probabilities are 25% affected, 50% carrier, and 25% unaffected/non-carrier for each pregnancy. Ovarian manifestations are sex/karyotype influenced, whereas hearing and neurologic manifestations can occur in either sex.
Variant severity can influence expressivity. More disruptive alleles in mitochondrial genes may produce broader combined oxidative-phosphorylation disease rather than the relatively restricted Perrault phenotype. (kline2022integralroleof pages 8-9, faridi2022newinsightsinto pages 1-3)

Environmental, lifestyle, and infectious risks

No toxin, infection, radiation exposure, smoking pattern, diet, occupation, or lifestyle factor has been established as a cause of Mendelian Perrault syndrome. The 2022 review explicitly notes that environmental etiologies remain to be identified for unresolved cases, which is a research gap rather than evidence for a known environmental cause. There are no established protective alleles, diets, supplements, vaccines, or exposure modifications that prevent the syndrome. (faridi2022newinsightsinto pages 1-3)

Gene–environment interaction

No reproducible Perrault-specific gene–environment interaction is known. General mitochondrial stressors could plausibly modify clinical expression, but this remains unproven. The 2024 CLPP-null metabolomics study proposed arginine/histidine supplementation as a hypothesis for growth deficits; this was model-derived and is not clinical efficacy evidence. (key2024clppnulleukaryoteswith pages 1-2)

3. Phenotypes

Manifestation	Type, onset, course, frequency	Suggested HPO terms
Bilateral SNHL	Defining sign in both sexes; congenital to adult onset; mild to profound; often childhood-onset and may be progressive. A recent CLPP literature synthesis reported hearing loss in 31/32 evaluable patients (97%), but this is gene-specific, not syndrome-wide.	HP:0000407 Sensorineural hearing impairment; HP:0000365 Hearing impairment; HP:0008619 Bilateral sensorineural hearing impairment; HP:0001730 Progressive hearing impairment
Auditory neuropathy	Uncommon; documented with TWNK, HARS2, and CLPP. Newborn screening may initially be normal before progressive disease.	HP:0012716 Auditory neuropathy
Primary ovarian insufficiency	Defining in affected 46,XX individuals; may become apparent during pubertal development or reproductive life.	HP:0008209 Premature ovarian insufficiency; HP:0000134 Female hypogonadism
Ovarian dysgenesis/streak or absent ovaries	Congenital developmental manifestation; variable from small ovaries to complete failure of development.	HP:0000133 Gonadal dysgenesis; HP:0008724 Hypoplasia of the ovary
Primary/secondary amenorrhea	Primary amenorrhea with failed puberty in severe disease; secondary amenorrhea in milder disease.	HP:0000786 Primary amenorrhea; HP:0000869 Secondary amenorrhea
Hypergonadotropic hypogonadism	Elevated FSH/LH and low estradiol. One MRPS7 case had FSH 102 IU/mL and estradiol 29 pg/mL.	HP:0008213 Hypergonadotropic hypogonadism; HP:0002925 Elevated circulating gonadotropin level; HP:0003230 Decreased circulating estrogen level
Infertility	Common consequence of ovarian failure; CLPP-associated male azoospermia has also been reported, although normal XY reproductive development is typical in classic definitions.	HP:0000789 Infertility; HP:0000027 Azoospermia
Neurologic disease	Variable: developmental delay/intellectual disability, ataxia, peripheral/motor neuropathy, muscle weakness/atrophy, nystagmus/limited eye movement, seizures, leukodystrophy or cerebellar atrophy. May be progressive. CLPP synthesis: 16/29 (55%) neurologic disease.	HP:0001250 Seizure; HP:0001251 Ataxia; HP:0001263 Global developmental delay; HP:0000762 Decreased nerve conduction velocity; HP:0001272 Cerebellar atrophy; HP:0002415 Leukodystrophy
Renal disease	Genotype-dependent, especially RMND1 and severe mitoribosomal disease; chronic kidney disease or renal failure.	HP:0012622 Chronic kidney disease; HP:0000083 Renal insufficiency
Growth and multisystem disease	Short stature/growth restriction, hepatic disease, cardiomyopathy, lactic acidosis, muscular disease, cataract or neutropenia occur in selected expanded-spectrum genotypes.	HP:0004322 Short stature; HP:0003128 Lactic acidosis; HP:0001638 Cardiomyopathy; HP:0001392 Abnormal liver morphology

The clinical impact is substantial: hearing loss affects communication, education, language development and employment; ovarian failure affects puberty, fertility, bone density, sexual health and psychosocial well-being; neurologic disease can impair gait and independent living. Nevertheless, no Perrault-specific EQ-5D, SF-36, PROMIS, or disease-specific quality-of-life cohort was identified. (faridi2022newinsightsinto pages 1-3, kline2022integralroleof pages 1-2, oziebło2020twonovelpathogenic pages 1-3, forli2021ararecase pages 1-2)

4. Genetic and molecular information

The following evidence-tiered table is appropriate for knowledge-base curation. “Expanded-spectrum/candidate” means that convincing case or functional evidence exists but the relationship may not yet have the same replication or expert-panel status as the core genes.

Gene	Molecular role / compartment	Evidence status	Representative phenotype or variant evidence	Key source DOI / PMID
CLPP	Mitochondrial matrix peptidase; mitochondrial protein quality control	Core established (2022 core set)	Biallelic CLPP variants cause Perrault syndrome type 3 with SNHL and POI; human and mouse loss causes infertility/deafness/ataxia; recent Chinese series summarized 33 PRLTS3 patients, with 97% hearing loss, 55% neurologic disease, 71% of females POI (faridi2022newinsightsinto pages 1-3, key2024clppnulleukaryoteswith pages 1-2, key2022clppdepletioncauses pages 1-2)	Faridi 2022 DOI: 10.1007/s00439-021-02319-7; Key 2024 DOI: 10.3390/biom14020241; Key 2022/Cells 2023 DOI: 10.3390/cells12010052
ERAL1	Mitochondrial 12S rRNA chaperone; small mitoribosomal subunit assembly	Core established (2022 core set)	Included among the eight genes with supporting evidence in the 2022 review; implicated in mitochondrial translation/ribosome assembly dysfunction in Perrault syndrome (faridi2022newinsightsinto pages 1-3, faridi2022newinsightsinto pages 11-13)	Faridi 2022 DOI: 10.1007/s00439-021-02319-7
GGPS1	Lipid/isoprenoid synthesis; geranylgeranyl diphosphate synthase	Core established (2022 core set)	Included in the eight-gene core set; genomic sequencing review classified it among metabolic causes of Perrault syndrome (faridi2022newinsightsinto pages 1-3, tucker2020genomicsequencinghighlights pages 1-7)	Faridi 2022 DOI: 10.1007/s00439-021-02319-7; Tucker 2020 DOI: 10.1007/s00439-020-02176-w
HARS2	Mitochondrial histidyl-tRNA synthetase; mitochondrial translation	Core established (2022 core set)	Included in the eight-gene core set; Perrault syndrome review notes HARS2-associated disease often lacks neurologic features relative to other genes (faridi2022newinsightsinto pages 1-3, faridi2022newinsightsinto pages 11-13)	Faridi 2022 DOI: 10.1007/s00439-021-02319-7
HSD17B4	Peroxisomal fatty-acid oxidation / steroid metabolism; peroxisome	Core established (2022 core set)	Included in the eight-gene core set; distinguished as a peroxisomal contributor to Perrault syndrome rather than a primary mitochondrial translation defect (faridi2022newinsightsinto pages 1-3, faridi2022newinsightsinto pages 11-13)	Faridi 2022 DOI: 10.1007/s00439-021-02319-7
LARS2	Mitochondrial leucyl-tRNA synthetase; mitochondrial translation	Core established (2022 core set)	Biallelic LARS2 mutations linked to premature ovarian failure and hearing loss in Perrault syndrome; repeatedly cited as a core mitochondrial translation gene (faridi2022newinsightsinto pages 1-3, key2022clppdepletioncauses pages 1-2)	Pierce 2013 DOI: 10.1016/j.ajhg.2013.03.007; Faridi 2022 DOI: 10.1007/s00439-021-02319-7
RMND1	Mitochondrial inner-membrane translation factor; couples mitochondrial transcript handling to translation	Core established (2022 core set)	Two adult sisters with compound heterozygous RMND1 variants c.583G>A (p.Gly195Arg) and c.818A>C (p.Tyr273Ser) had SNHL, ovarian dysfunction, and chronic kidney disease, providing independent confirmation of causality (oziebło2020twonovelpathogenic pages 1-3, oziebło2020twonovelpathogenic pages 3-5)	Oziębło 2020 DOI: 10.3390/genes11091060
TWNK	Twinkle mtDNA helicase; mitochondrial DNA maintenance / nucleoid	Core established (2022 core set)	Included in the eight-gene core set; recognized as an mtDNA maintenance cause of Perrault syndrome and auditory neuropathy-spectrum presentations in literature review (faridi2022newinsightsinto pages 1-3, forli2021ararecase pages 1-2)	Faridi 2022 DOI: 10.1007/s00439-021-02319-7
PRORP	Mitochondrial RNase P catalytic subunit; mitochondrial tRNA 5′-processing	Expanded-spectrum / newer established beyond 2022 core set	Bi-allelic PRORP variants caused impaired mitochondrial tRNA processing with decreased protein levels, rescue by WT cDNA, and multisystem presentations including SNHL and POI; earlier family had ~35–45% reduction in 5′-processed tRNA in RNase P assays (hochberg2021biallelicvariantsin pages 1-2)	Hochberg 2021 DOI: 10.1016/j.ajhg.2021.10.002; preprint DOI: 10.1101/168252
TFAM	Mitochondrial transcription factor A; mtDNA packaging/maintenance	Expanded-spectrum / candidate	Genomic sequencing paper highlighted TFAM among mtDNA maintenance/translation causes in Perrault syndrome pedigrees, but it was not part of the 2022 eight-gene core set (tucker2020genomicsequencinghighlights pages 1-7, kline2022integralroleof pages 1-2)	Tucker 2020 DOI: 10.1007/s00439-020-02176-w
PEX6	Peroxisome biogenesis ATPase; peroxisome	Expanded-spectrum / candidate	Genomic sequencing study identified PEX6 as a peroxisomal molecular cause in individuals labeled Perrault syndrome, supporting expansion beyond classic mitochondrial genes (tucker2020genomicsequencinghighlights pages 1-7, faridi2022newinsightsinto pages 11-13)	Tucker 2020 DOI: 10.1007/s00439-020-02176-w
MRPS7	Mitochondrial ribosomal small-subunit protein 7; mitoribosome	Expanded-spectrum / candidate	Compound heterozygous MRPS7 variants *c.373A>T (p.Lys125) and c.536G>A (p.Arg179His)** in a 25-year-old woman with hearing loss and POI; authors state this “validates” MRPS7 as a cause of syndromic POI/Perrault syndrome (kline2022integralroleof pages 1-2, kline2022integralroleof pages 5-8, kline2022integralroleof pages 8-9)	Kline 2022 DOI: 10.3390/genes13112113
MRPL50	Mitochondrial ribosomal large-subunit protein; mitoribosome	Expanded-spectrum / candidate	Mentioned in the 2025 DAP3 study summary as part of the broader Perrault-spectrum literature involving mitochondrial ribosomal defects, but detailed primary evidence was not retrieved here (smith2025biallelicvariantsin pages 15-16)	Cited in summary as Bakhshalizadeh 2023 DOI: 10.1007/s00439-023-02563-z
DAP3 / MRPS29	Mitoribosomal small-subunit protein / GTPase-related apoptosis factor; mitochondrion	Expanded-spectrum / candidate	Five unrelated individuals with bi-allelic DAP3 variants had phenotypes ranging from classic Perrault syndrome (SNHL + ovarian insufficiency) to childhood neurometabolic disease; fibroblasts showed reduced MRPS29 and combined complex I/IV deficiency (smith2025biallelicvariantsin pages 1-2, smith2025biallelicvariantsin pages 15-16)	Smith 2025 DOI: 10.1016/j.ajhg.2024.11.007
MRPL43	Mitochondrial ribosomal large-subunit protein; mitoribosome	Possible emerging association only	Listed by Open Targets disease-target mapping for Perrault syndrome, but no supporting primary paper was retrieved in the present evidence set (OpenTargets Search: Perrault syndrome)	No primary source retrieved here
MRPL49	Mitochondrial ribosomal large-subunit protein; mitoribosome	Possible emerging association only	Listed by Open Targets disease-target mapping for Perrault syndrome, but no supporting primary paper was retrieved in the present evidence set (OpenTargets Search: Perrault syndrome)	No primary source retrieved here

Table: This table separates the 2022 eight-gene core Perrault syndrome set from expanded-spectrum and candidate genes supported by later mitochondrial/peroxisomal studies. It is useful for knowledge-base curation because it links each gene to its molecular role, evidence tier, representative phenotype evidence, and source citations.

Variant characteristics

The reported disease alleles include missense, nonsense, frameshift, splice-site, small indel, and large deletion variants. Examples include:

MRPS7: compound heterozygous c.373A>T, p.(Lys125*) and c.536G>A, p.(Arg179His). The nonsense allele is predicted to undergo nonsense-mediated decay; structural analysis suggested p.Arg179His disrupts salt bridges and protein stability. (kline2022integralroleof pages 5-8, kline2022integralroleof pages 8-9)
RMND1: compound heterozygous c.583G>A, p.(Gly195Arg) and c.818A>C, p.(Tyr273Ser), classified as likely pathogenic in the reported family; each was seen only in isolated heterozygous individuals in gnomAD. (oziebło2020twonovelpathogenic pages 3-5, oziebło2020twonovelpathogenic pages 1-3)
PRORP: biallelic missense, duplication/frameshift and other alleles caused reduced protein, impaired mt-tRNA processing and downstream mitochondrial protein deficiency. (hochberg2021biallelicvariantsin pages 1-2)
CLPP: both missense and truncating/splice/deletion alleles occur. Functional consequences include reduced or absent protease activity and failure of mitochondrial protein-quality control. (key2024clppnulleukaryoteswith pages 1-2, key2022clppdepletioncauses pages 1-2)

Exact gnomAD frequencies must be recorded per genomic build, transcript and variant; they should not be inferred from case reports. Pathogenic variants are expected to be absent or very rare and compatible with recessive disease. Variant interpretation should follow ACMG/AMP criteria using segregation, population frequency, phenotype specificity, computational/structural evidence and functional data. No validated somatic mechanism, repeat expansion, recurrent aneuploidy, or characteristic balanced translocation is known.

Modifier and epigenetic information

No confirmed modifier gene or protective allele has been established. No reproducible disease-specific DNA-methylation episignature, histone signature, or chromatin abnormality is currently used diagnostically. Model findings of histone H3 cleavage and altered one-carbon metabolism are mechanistic observations, not a validated human epigenetic biomarker. (key2024clppnulleukaryoteswith pages 1-2, key2022clppdepletioncauses pages 1-2)

5. Environmental information

Perrault syndrome is not infectious, toxic, occupational, radiation induced, or lifestyle caused. No pathogen or zoonotic mechanism applies. General measures such as avoiding ototoxic exposure and optimizing nutrition may protect residual function or general health but do not prevent the inherited disorder. No Perrault-specific evidence links tobacco, alcohol, exercise, pollution, or diet to penetrance.

6. Mechanism and pathophysiology

Unifying causal chain

Biallelic germline variant → impaired mitochondrial/peroxisomal protein function → defective mtRNA processing, mitoribosome assembly/translation, mtDNA maintenance, proteostasis, lipid/fatty-acid metabolism, or peroxisome biogenesis → impaired oxidative phosphorylation and cellular stress → selective vulnerability of cochlear auditory cells/neurons and ovarian germ/follicular cells → SNHL and ovarian insufficiency; greater residual dysfunction produces neurologic, renal, muscular, hepatic, cardiac, or developmental disease. (kline2022integralroleof pages 1-2, smith2025biallelicvariantsin pages 1-2, hochberg2021biallelicvariantsin pages 1-2)

Upstream molecular modules

Mitochondrial translation and mitoribosome assembly: HARS2 and LARS2 aminoacylate mitochondrial tRNAs; ERAL1 supports 12S-rRNA/small-subunit assembly; MRPS7, MRPL50 and DAP3 are mitoribosomal proteins; RMND1 supports mitochondrial translation near the inner membrane. Deficiency decreases synthesis of the 13 mtDNA-encoded oxidative-phosphorylation subunits. (smith2025biallelicvariantsin pages 1-2, kline2022integralroleof pages 1-2, oziebło2020twonovelpathogenic pages 1-3)
mtRNA processing: PRORP is the metallonuclease subunit of mitochondrial RNase P and processes mitochondrial precursor-tRNA 5′ ends. Patient fibroblasts accumulated unprocessed transcripts and lost mitochondrial-encoded proteins; wild-type cDNA rescued these defects. (hochberg2021biallelicvariantsin pages 1-2)
mtDNA maintenance: TWNK helicase and TFAM support mtDNA replication, packaging and transcription.
Proteostasis: CLPP is the proteolytic component of the mitochondrial CLPXP complex. Its loss causes CLPX and nucleoid-associated protein accumulation, mtDNA/protein mispackaging, stress signaling and metabolic disruption. (key2024clppnulleukaryoteswith pages 1-2, key2022clppdepletioncauses pages 1-2)
Peroxisomal/metabolic pathways: HSD17B4 affects peroxisomal fatty-acid oxidation/steroid metabolism; PEX6 affects peroxisome biogenesis; GGPS1 affects isoprenoid/lipid metabolism. These findings show that Perrault is a convergent phenotype, not a single-pathway disorder. (kline2022integralroleof pages 1-2, tucker2020genomicsequencinghighlights pages 1-7)

Downstream processes and tissue injury

Downstream mechanisms include combined respiratory-chain deficiency, ATP limitation, altered redox and metabolite homeostasis, mitochondrial stress, inappropriate apoptosis or altered apoptotic sensitivity, and—in CLPP models—mtDNA extrusion and cGAS–STING-related innate signaling. Deleting downstream STING/IFNAR did not rescue CLPP-null mouse infertility, indicating that inflammatory signaling is not the sole upstream driver. (smith2025biallelicvariantsin pages 1-2, key2022clppdepletioncauses pages 1-2)

Molecular profiling and recent research

Proteomics/transcriptomics: CLPP-null testis showed loss of meiotic proteins HSPA2, SHCBP1L, DMRT7 and HSF5, accumulation of AURKAIP1 and Perrault proteins ERAL1, PEO1/TWNK and HARS2, and no meiotic M-phase cells. (key2022clppdepletioncauses pages 1-2)
Metabolomics, 2024: CLPP-null Podospora anserina and mouse cerebellum showed reduced arginine/histidine; mouse cerebellum additionally had reduced citrulline and accumulated protoporphyrin IX, supporting dysregulated CLPX–ALAS/OAT and heme/amino-acid metabolism. Translation to patients is unproven. Publication: 19 February 2024; DOI: https://doi.org/10.3390/biom14020241. (key2024clppnulleukaryoteswith pages 1-2)
Functional genomics, late 2024: five unrelated individuals with biallelic DAP3 variants ranged from classic Perrault syndrome to childhood neurometabolic disease. Fibroblasts showed reduced MRPS29/DAP3, destabilization of the small mitoribosomal subunit and combined complex I/IV deficiency; wild-type DAP3 partially rescued molecular defects. Online publication was in December 2024; issue date 2 January 2025; DOI: https://doi.org/10.1016/j.ajhg.2024.11.007. (smith2025biallelicvariantsin pages 1-2)
No mature Perrault-specific single-cell atlas, spatial-transcriptomic study, patient multi-omics classifier, CRISPR screen, proteomic diagnostic or metabolomic diagnostic was identified. The 2022 review did examine single-cell RNA-seq expression patterns for the eight core genes, but this remains mechanistic rather than diagnostic evidence. (faridi2022newinsightsinto pages 1-3)

Suggested GO and Cell Ontology annotations

GO biological processes: mitochondrial translation (GO:0032543); mitochondrial RNA processing (GO:0000963); mitochondrial DNA replication (GO:0006264/mitochondrial child term); protein quality control; oxidative phosphorylation (GO:0006119); peroxisome organization (GO:0007031); fatty-acid beta-oxidation (GO:0006635); apoptotic process (GO:0006915); meiotic cell cycle (GO:0051321).
GO cellular components: mitochondrion (GO:0005739); mitochondrial matrix (GO:0005759); mitochondrial inner membrane (GO:0005743); mitochondrial ribosome (GO:0005761); peroxisome (GO:0005777); mitochondrial nucleoid (GO:0042645).
Candidate CL terms: cochlear inner/outer hair cell, auditory neuron/spiral-ganglion neuron, ovarian granulosa cell, oocyte, germ cell, spermatocyte, renal tubular epithelial cell, cerebellar Purkinje cell and peripheral neuron. Exact current CL identifiers should be validated against the ontology release before loading.

7. Anatomical structures affected

Primary anatomy

Inner ear/auditory system: bilateral cochlear sensory epithelium, hair-cell synapses, auditory nerve/spiral ganglion; auditory neuropathy indicates that pre- or postsynaptic neural components can also be involved. Suggested UBERON: inner ear, cochlea, organ of Corti, vestibulocochlear nerve.
Ovary/reproductive axis: ovaries, ovarian follicles/germ cells and secondary estrogen-dependent tissues. The endocrine defect is peripheral ovarian failure, not primarily pituitary disease. Suggested UBERON: ovary, ovarian follicle, uterus.

Secondary/genotype-specific anatomy

Cerebellum, cerebral white matter, peripheral nerves, skeletal muscle, kidneys, liver, heart and testes can be involved. MRI may show leukodystrophy or cerebellar atrophy; kidney disease is particularly important in RMND1 or severe mitochondrial-ribosomal phenotypes. (oziebło2020twonovelpathogenic pages 1-3, forli2021ararecase pages 1-2)

Localization and lateralization

Hearing impairment is characteristically bilateral, although severity can be asymmetric. Ovarian involvement is generally bilateral/systemic. Subcellular compartments are predominantly the mitochondrial matrix, inner membrane, mitoribosome, mtRNA-processing machinery and nucleoid; HSD17B4/PEX6 disease additionally implicates peroxisomes.

8. Temporal development

SNHL is often the first recognized feature and may be congenital, detected in childhood, or appear later. It may be stable or progressive. A CLPP case passed newborn otoacoustic-emission and automated auditory-brainstem screening but later developed progressive auditory neuropathy, showing that a normal newborn screen does not exclude Perrault syndrome. (forli2021ararecase pages 1-2)

Ovarian dysfunction is biologically developmental but often becomes clinically apparent at puberty through delayed/absent pubertal development and primary amenorrhea, or later through irregular menses, secondary amenorrhea and infertility. Neurologic disease can emerge later and progress. In one RMND1 family, hearing loss was diagnosed at ages 3–4, reproductive abnormalities at 17–18, and chronic kidney disease in the fourth decade. (oziebło2020twonovelpathogenic pages 1-3)

The condition is chronic and lifelong. There is no recognized spontaneous or treatment-induced molecular remission. Critical intervention windows include early hearing/language rehabilitation, prepubertal or early-pubertal endocrine evaluation, timely sex-steroid replacement, fertility preservation discussion before follicular reserve is exhausted, and early surveillance for genotype-specific organ disease.

9. Inheritance and population

Epidemiology

Perrault syndrome is extremely rare, but no reliable population prevalence, incidence per 100,000, mortality rate, carrier frequency, or sex ratio has been established. Published evidence consists predominantly of small pedigrees and selected sequencing cohorts. Therefore, disease burden cannot responsibly be extrapolated from the gene-specific CLPP series or from the proportion of molecularly unresolved cases.

Inheritance characteristics

Autosomal recessive, with sex-influenced reproductive expression.
Penetrance of the defining phenotype appears high in reported biallelic cases, but precise age-adjusted penetrance is unknown.
Expressivity is markedly variable both across and within genes.
No anticipation has been reported.
Germline mosaicism is theoretically possible but not established as a recurrent mechanism.
Founder alleles may exist in particular pedigrees/populations, but no single global founder mutation explains the disease.
Consanguinity is relevant to homozygous cases; compound heterozygosity is also common.
There is no known endemic region or established ethnicity-specific prevalence. Apparent geographic clustering reflects ascertainment and consanguinity more than proven population risk.

10. Diagnostics

Clinical recognition

Perrault syndrome should be considered in:

any 46,XX person with SNHL plus delayed puberty, amenorrhea, hypergonadotropic hypogonadism, small/streak ovaries or infertility;
siblings of either sex with unexplained bilateral SNHL when a sister has ovarian insufficiency;
SNHL plus ataxia, neuropathy, leukodystrophy, renal disease or other mitochondrial signs.

Clinical testing

Audiology: pure-tone audiometry, tympanometry, otoacoustic emissions, auditory brainstem responses and speech testing; evaluate auditory neuropathy and progression.
Endocrine/reproductive: FSH, LH, estradiol, anti-Müllerian hormone where informative; menstrual and pubertal assessment; pelvic ultrasound for uterine/ovarian size; karyotype to document 46,XX and exclude sex-chromosome causes.
Neurology: examination, nerve-conduction/EMG studies where indicated, brain MRI for white-matter or cerebellar abnormalities.
Organ surveillance: creatinine/eGFR, urinalysis and blood pressure; liver enzymes, lactate, glucose, CK, cardiac assessment and ophthalmology guided by genotype/phenotype.
Biopsy: muscle biopsy may show mitochondrial pathology but is not required when molecular diagnosis is obtained and should not be routine.

Genetic-testing strategy

Use a comprehensive hearing-loss/POI/mitochondrial-peroxisomal panel that includes at minimum the eight core genes and validated expanded-spectrum genes.
If negative, proceed to trio WES or WGS with copy-number and mitochondrial-disease-aware analysis. WGS is advantageous for exon-level/large deletions, noncoding splice variants and structural variants.
Confirm candidate variants and phase by parental testing/Sanger or equivalent methods.
Apply RNA studies/minigene assays for splice variants and functional studies where gene–disease validity or variant interpretation is uncertain.
CMA/karyotype is useful principally for differential diagnosis of POI or syndromic disease, not as the highest-yield test for classic Perrault syndrome. FISH and repeat-expansion testing are not routine. mtDNA sequencing may be warranted for broader mitochondrial differentials, but classic Perrault genes are nuclear encoded.

A real-world 237-gene hearing-loss panel successfully identified compound-heterozygous RMND1 variants after analysis against gnomAD, ClinVar, HGMD and ACMG/AMP criteria. (oziebło2020twonovelpathogenic pages 3-5, oziebło2020twonovelpathogenic pages 1-3)

Differential diagnosis

Important alternatives include nonsyndromic hereditary deafness coinciding with unrelated POI; Turner syndrome or X-chromosome abnormalities; FMR1 premutation-associated POI; autoimmune or iatrogenic POI; congenital infection; ototoxic injury; Zellweger-spectrum/D-bifunctional protein deficiency; combined oxidative-phosphorylation disorders; Woodhouse–Sakati syndrome; Gordon Holmes/Boucher–Neuhäuser and other ataxia-hypogonadism syndromes; and syndromic hearing-loss disorders such as Alström or mitochondrial cytopathies. The possibility of two independent monogenic diagnoses should be retained when phenotype or segregation is discordant. (faridi2022newinsightsinto pages 11-13)

Screening

Perrault syndrome is not on routine newborn biochemical screening panels. Universal newborn hearing screening can detect congenital disease but can miss later-onset/progressive auditory neuropathy. Cascade testing of relatives is appropriate after molecular diagnosis. Reproductive options include carrier testing, prenatal diagnosis and preimplantation genetic testing for a known familial genotype.

11. Outcome and prognosis

There are no robust 5- or 10-year survival estimates or disease-specific mortality rates. Classic type 1 disease is not generally considered life-shortening, but morbidity from deafness, infertility, estrogen deficiency and osteoporosis is important. Severe alleles in RMND1, MRPS7, DAP3 and other mitochondrial genes can cause renal/hepatic failure, cardiomyopathy, encephalopathy or early death; thus prognosis is genotype- and residual-function dependent. One previously reported MRPS7-affected sister died in early adolescence from liver and renal failure, illustrating the expanded spectrum rather than the expected course of every patient. (kline2022integralroleof pages 8-9, kline2022integralroleof pages 1-2)

Hearing loss generally does not spontaneously recover, although assistive technology can substantially improve communication. Ovarian reserve is not restored by hormone replacement; spontaneous ovarian activity may occur in POI generally, but no Perrault-specific recovery rate is known. Neurologic progression is variable. Prognostic biomarkers beyond genotype, baseline organ involvement and longitudinal audiologic/endocrine measures are not validated.

12. Treatment and real-world implementation

Hearing management

Early hearing aids, speech/language therapy, educational support and sign-language access should be offered according to patient preference and auditory phenotype. Cochlear implantation is appropriate for severe/profound loss or poor aided speech recognition, including selected auditory-neuropathy cases. In RMND1-associated disease, bilateral implantation at ages 34 and 36 produced a reported “good outcome.” (oziebło2020twonovelpathogenic pages 1-3)

Suggested NCIt concepts: Hearing Aid, Cochlear Implantation, Speech Therapy, Rehabilitation Therapy.

Endocrine, bone and reproductive care

Physiologic estrogen replacement with cyclic progestogen when a uterus is present supports pubertal development, menstrual management, bone health and cardiovascular/urogenital health. Monitor bone mineral density, vitamin D/calcium status and cardiovascular risk. In the RMND1 family, both affected sisters received estradiol plus dydrogesterone; one had osteoporosis. (oziebło2020twonovelpathogenic pages 1-3)

Fertility counseling should occur early. Depending on residual ovarian function, options may include fertility preservation, assisted reproduction, donor oocytes/embryos, gestational or adoption pathways consistent with local law and patient goals. No genotype-specific response rate is available.

Suggested NCIt concepts: Hormone Replacement Therapy, Estradiol, Progesterone, In Vitro Fertilization, Oocyte Donation, Fertility Preservation Procedure.

Neurologic and multisystem management

Physical/occupational therapy, mobility aids, seizure treatment, neuropathy management and educational support are individualized. Genotype-directed renal, hepatic, cardiac and metabolic surveillance is essential. There is no established Perrault pharmacogenomic rule or approved mitochondrial cocktail.

Advanced/experimental therapies and trials

No approved gene replacement, CRISPR, cell therapy, antisense/siRNA, mRNA or targeted small-molecule therapy exists. The clinical-trial search identified a broad observational deafness genetics study (NCT00341874), not a Perrault-specific therapeutic trial. The 2024 arginine/histidine supplementation proposal is preclinical and should not be presented as treatment. No response rates or controlled adverse-event data exist for disease-modifying therapy. (key2024clppnulleukaryoteswith pages 1-2)

13. Prevention

Primary prevention

The inherited molecular defect cannot currently be prevented through lifestyle change, vaccination or prophylactic medication. The applicable primary-prevention strategy is reproductive genetic counseling with optional carrier, prenatal or preimplantation testing after familial variants are established.

Secondary prevention

Cascade testing and baseline audiology/endocrine evaluation of at-risk siblings.
Serial hearing assessment despite a normal newborn screen.
Early FSH/LH/estradiol and pubertal assessment in girls with unexplained SNHL.
Early fertility counseling before established ovarian failure where feasible.

Tertiary prevention

Early auditory rehabilitation reduces language/educational consequences; hormone replacement and bone surveillance reduce estrogen-deficiency complications; organ surveillance may identify renal, hepatic, cardiac or neurologic complications before irreversible decline. No vaccine, antimicrobial prophylaxis, public-health sanitation measure or environmental remediation is disease-specific.

14. Other species and natural disease

There is no evidence that Perrault syndrome is transmissible, zoonotic or infectious. Orthologs of the causal genes are broadly conserved across eukaryotes, particularly genes governing mitochondrial translation and CLP proteostasis. Relevant experimental taxa include:

Mus musculus, NCBI Taxon 10090—CLPP-null and other engineered models.
Podospora anserina, a filamentous ascomycete—CLPP-null comparative aging/metabolism model.
Human patient fibroblasts and recombinant-protein systems.

No well-established naturally occurring companion-animal breed syndrome equivalent to human Perrault syndrome was identified in the retrieved literature. Veterinary breed/VBO annotations and natural-disease transmission are therefore not applicable on current evidence.

15. Model organisms and experimental systems

CLPP-null mouse

CLPP loss in mice reproduces growth deficits, infertility, deafness and ataxia, providing a strong multisystem model of PRLTS3. In male testis, chromosome pairing occurred, but crossover-marker abnormalities, persistent γH2AX, premature desynapsis, absence of meiotic M-phase cells and cell death indicated late-prophase/diplotene arrest. mtDNA extrusion and cGAMP increased, but STING/IFNAR deletion failed to rescue pathology. Strengths are organism-level auditory, neurologic and reproductive phenotypes; limitations include especially severe male infertility and incomplete correspondence to variable human alleles. (key2022clppdepletioncauses pages 1-2)

Fungal CLPP-null model

P. anserina CLPP loss produces longevity rather than the mammalian syndrome, but provides experimentally tractable proteomic/metabolomic evidence concerning CLPX, ALAS/OAT, heme synthesis and arginine/histidine depletion. It is useful for conserved mitochondrial proteostasis, not for human ovarian or auditory anatomy. (key2024clppnulleukaryoteswith pages 1-2)

Patient fibroblasts and rescue systems

PRORP patient fibroblasts demonstrated accumulated unprocessed mitochondrial transcripts and reduced mitochondrial proteins, rescued by wild-type PRORP cDNA. Recombinant RNase-P assays confirmed diminished tRNA processing. These systems strongly establish variant mechanism but cannot reproduce tissue-selective ovarian or cochlear degeneration. (hochberg2021biallelicvariantsin pages 1-2)

DAP3 patient fibroblasts and recombinant-protein assays showed reduced mitoribosomal small-subunit assembly, complex I/IV deficiency, altered thermal stability/GTPase function and altered apoptotic sensitivity; wild-type DAP3 partly rescued molecular abnormalities. This is compelling functional evidence for an emerging Perrault-spectrum gene but needs larger cohorts and longitudinal phenotype data. (smith2025biallelicvariantsin pages 1-2)

No mature Perrault-specific organoid, humanized knock-in, spatial-transcriptomic, or therapeutic CRISPR model was identified.

Key recent developments, 2023–2024

Mitoribosomal expansion: a 2023 report implicated MRPL50 deficiency in the Perrault spectrum, strengthening the view that both large and small mitoribosomal subunits are critical to ovarian and auditory function; detailed primary evidence should be independently curated before assigning definitive status. DOI: https://doi.org/10.1007/s00439-023-02563-z. (smith2025biallelicvariantsin pages 15-16)
CLPP meiotic mechanism: the 2023 Cells study localized CLPP-null germ-cell failure to late meiotic prophase and showed that downstream STING/IFNAR removal did not rescue infertility. DOI: https://doi.org/10.3390/cells12010052. (key2022clppdepletioncauses pages 1-2)
CLPP metabolic mechanism, 2024: cross-species metabolomics linked CLPP loss to altered heme biosynthesis and reduced arginine/histidine/citrulline, generating a testable—but not yet clinical—nutritional hypothesis. DOI: https://doi.org/10.3390/biom14020241. (key2024clppnulleukaryoteswith pages 1-2)
DAP3 discovery, December 2024: biallelic DAP3 variants in five unrelated individuals established a mitoribosomal-small-subunit/combined-OXPHOS Perrault-spectrum disorder through genetic, proteomic, rescue and biochemical evidence. DOI: https://doi.org/10.1016/j.ajhg.2024.11.007. (smith2025biallelicvariantsin pages 1-2)

Selected exact abstract quotations and source metadata

Faridi et al., accepted 14 July 2021; Human Genetics 2022: “Variants of these eight genes only account for approximately half of the individuals with clinical features of Perrault syndrome where the molecular genetic base remains under investigation.” DOI: https://doi.org/10.1007/s00439-021-02319-7. (faridi2022newinsightsinto pages 1-3)
Kline et al., published 14 November 2022: “This second independent report validates that variants in MRPS7 are a cause of syndromic POI/Perrault syndrome.” DOI: https://doi.org/10.3390/genes13112113. (kline2022integralroleof pages 1-2)
Hochberg et al., published 4 November 2021: “Fibroblasts from affected individuals in two families demonstrated decreased steady state levels of PRORP, an accumulation of unprocessed mitochondrial transcripts, and decreased steady state levels of mitochondrial-encoded proteins, which were rescued by introduction of the wild-type PRORP cDNA.” DOI: https://doi.org/10.1016/j.ajhg.2021.10.002; PMID 34715011, https://pubmed.ncbi.nlm.nih.gov/34715011/. (hochberg2021biallelicvariantsin pages 1-2)
Oziębło et al., published 8 September 2020: “Our study presents the mildest, so far reported, RMND1-related phenotype and delivers the first independent confirmation that RMND1 is causally involved in the development of Perrault syndrome with renal involvement.” DOI: https://doi.org/10.3390/genes11091060. (oziebło2020twonovelpathogenic pages 1-3)
Smith et al., online December 2024/issue 2 January 2025: “Here, we describe five unrelated individuals with bi-allelic variants in death-associated protein 3 (DAP3) … with variable clinical presentations ranging from Perrault syndrome … to an early childhood neurometabolic phenotype.” DOI: https://doi.org/10.1016/j.ajhg.2024.11.007. (smith2025biallelicvariantsin pages 1-2)

Evidence limitations

The central limitations are extreme rarity, retrospective ascertainment, small pedigrees, inconsistent historical gene lists, incomplete follow-up of 46,XY individuals, and frequent use of “Perrault-like” or “Perrault-spectrum” for broader mitochondrial disorders. Syndrome-wide phenotype percentages, penetrance, prevalence, life expectancy, quality-of-life scores, carrier frequencies, and treatment-response rates are not currently robust. Knowledge-base curation should therefore preserve evidence tier, publication date, exact genotype, sex/karyotype, phenotype age, functional evidence and whether the source represents classic Perrault syndrome or an expanded multisystem spectrum.

References

(faridi2022newinsightsinto pages 1-3): Rabia Faridi, Alessandro Rea, Cristina Fenollar-Ferrer, Raymond T. O’Keefe, Shoujun Gu, Zunaira Munir, Asma Ali Khan, Sheikh Riazuddin, Michael Hoa, Sadaf Naz, William G. Newman, and Thomas B. Friedman. New insights into perrault syndrome, a clinically and genetically heterogeneous disorder. Human Genetics, 141:805-819, Aug 2022. URL: https://doi.org/10.1007/s00439-021-02319-7, doi:10.1007/s00439-021-02319-7. This article has 51 citations and is from a peer-reviewed journal.
(kline2022integralroleof pages 1-2): Brianna L. Kline, Sylvie Jaillard, Katrina M. Bell, Shabnam Bakhshalizadeh, Gorjana Robevska, Jocelyn van den Bergen, Jérôme Dulon, Katie L. Ayers, John Christodoulou, Michel C. Tchan, Philippe Touraine, Andrew H. Sinclair, and Elena J. Tucker. Integral role of the mitochondrial ribosome in supporting ovarian function: mrps7 variants in syndromic premature ovarian insufficiency. Genes, 13:2113, Nov 2022. URL: https://doi.org/10.3390/genes13112113, doi:10.3390/genes13112113. This article has 18 citations.
(smith2025biallelicvariantsin pages 1-2): Thomas B. Smith, Robert Kopajtich, Leigh A.M. Demain, Alessandro Rea, Huw B. Thomas, Manuel Schiff, Christian Beetz, Shelagh Joss, Gerard S. Conway, Anju Shukla, Mayuri Yeole, Periyasamy Radhakrishnan, Hatem Azzouz, Amel Ben Chehida, Monique Elmaleh-Bergès, Ruth I.C. Glasgow, Kyle Thompson, Monika Oláhová, Langping He, Emma M. Jenkinson, Amir Jahic, Inna A. Belyantseva, Melanie Barzik, Jill E. Urquhart, James O’Sullivan, Simon G. Williams, Sanjeev S. Bhaskar, Samantha Carrera, Alexander J.M. Blakes, Siddharth Banka, Wyatt W. Yue, Jamie M. Ellingford, Henry Houlden, Kevin J. Munro, Thomas B. Friedman, Robert W. Taylor, Holger Prokisch, Raymond T. O’Keefe, and William G. Newman. Bi-allelic variants in dap3 result in reduced assembly of the mitoribosomal small subunit with altered apoptosis and a perrault-syndrome-spectrum phenotype. Jan 2025. URL: https://doi.org/10.1016/j.ajhg.2024.11.007, doi:10.1016/j.ajhg.2024.11.007. This article has 11 citations.
(faridi2022newinsightsinto pages 11-13): Rabia Faridi, Alessandro Rea, Cristina Fenollar-Ferrer, Raymond T. O’Keefe, Shoujun Gu, Zunaira Munir, Asma Ali Khan, Sheikh Riazuddin, Michael Hoa, Sadaf Naz, William G. Newman, and Thomas B. Friedman. New insights into perrault syndrome, a clinically and genetically heterogeneous disorder. Human Genetics, 141:805-819, Aug 2022. URL: https://doi.org/10.1007/s00439-021-02319-7, doi:10.1007/s00439-021-02319-7. This article has 51 citations and is from a peer-reviewed journal.
(oziebło2020twonovelpathogenic pages 1-3): Dominika Oziębło, Joanna Pazik, Iwona Stępniak, Henryk Skarżyński, and Monika Ołdak. Two novel pathogenic variants confirm rmnd1 causative role in perrault syndrome with renal involvement. Genes, 11:1060, Sep 2020. URL: https://doi.org/10.3390/genes11091060, doi:10.3390/genes11091060. This article has 30 citations.
(OpenTargets Search: Perrault syndrome): Open Targets Query (Perrault syndrome, 31 results). Buniello, A. et al. (2025). Open Targets Platform: facilitating therapeutic hypotheses building in drug discovery. Nucleic Acids Research.
(forli2021ararecase pages 1-2): Francesca Forli, Luca Bruschini, Beatrice Franciosi, Roberta Battini, Gemma Marinella, Stefano Berrettini, and Francesco Lazzerini. A rare case of perrault syndrome with auditory neuropathy spectrum disorder: cochlear implantation treatment and literature review. Audiology Research, 11:609-617, Nov 2021. URL: https://doi.org/10.3390/audiolres11040055, doi:10.3390/audiolres11040055. This article has 13 citations.
(hochberg2021biallelicvariantsin pages 1-2): Irit Hochberg, Leigh A.M. Demain, Julie Richer, Kyle Thompson, Jill E. Urquhart, Alessandro Rea, Waheeda Pagarkar, Agustí Rodríguez-Palmero, Agatha Schlüter, Edgard Verdura, Aurora Pujol, Pilar Quijada-Fraile, Albert Amberger, Andrea J. Deutschmann, Sandra Demetz, Meredith Gillespie, Inna A. Belyantseva, Hugh J. McMillan, Melanie Barzik, Glenda M. Beaman, Reeya Motha, Kah Ying Ng, James O’Sullivan, Simon G. Williams, Sanjeev S. Bhaskar, Isabella R. Lawrence, Emma M. Jenkinson, Jessica L. Zambonin, Zeev Blumenfeld, Sergey Yalonetsky, Stephanie Oerum, Walter Rossmanith, Wyatt W. Yue, Johannes Zschocke, Kevin J. Munro, Brendan J. Battersby, Thomas B. Friedman, Robert W. Taylor, Raymond T. O’Keefe, and William G. Newman. Bi-allelic variants in the mitochondrial rnase p subunit prorp cause mitochondrial trna processing defects and pleiotropic multisystem presentations. The American Journal of Human Genetics, 108:2195-2204, Nov 2021. URL: https://doi.org/10.1016/j.ajhg.2021.10.002, doi:10.1016/j.ajhg.2021.10.002. This article has 53 citations.
(kline2022integralroleof pages 8-9): Brianna L. Kline, Sylvie Jaillard, Katrina M. Bell, Shabnam Bakhshalizadeh, Gorjana Robevska, Jocelyn van den Bergen, Jérôme Dulon, Katie L. Ayers, John Christodoulou, Michel C. Tchan, Philippe Touraine, Andrew H. Sinclair, and Elena J. Tucker. Integral role of the mitochondrial ribosome in supporting ovarian function: mrps7 variants in syndromic premature ovarian insufficiency. Genes, 13:2113, Nov 2022. URL: https://doi.org/10.3390/genes13112113, doi:10.3390/genes13112113. This article has 18 citations.
(key2024clppnulleukaryoteswith pages 1-2): Jana Key, Suzana Gispert, Arvind Reddy Kandi, Daniela Heinz, Andrea Hamann, Heinz D. Osiewacz, David Meierhofer, and Georg Auburger. Clpp-null eukaryotes with excess heme biosynthesis show reduced l-arginine levels, probably via clpx-mediated oat activation. Biomolecules, 14:241, Feb 2024. URL: https://doi.org/10.3390/biom14020241, doi:10.3390/biom14020241. This article has 4 citations.
(key2022clppdepletioncauses pages 1-2): Jana Key, Suzana Gispert, Lieke Koornneef, Esther Sleddens-Linkels, Aneesha Kohli, Sylvia Torres-Odio, Gabriele Koepf, Shady Amr, Marina Reichlmeir, Patrick N. Harter, Andrew Phillip West, Christian Münch, Willy M. Baarends, and Georg Auburger. Clpp depletion causes diplotene arrest; underlying testis mitochondrial dysfunction occurs with accumulation of perrault proteins eral1, peo1, and hars2. Cells, 12:52, Dec 2022. URL: https://doi.org/10.3390/cells12010052, doi:10.3390/cells12010052. This article has 15 citations.
(tucker2020genomicsequencinghighlights pages 1-7): Elena J. Tucker, Rocio Rius, Sylvie Jaillard, Katrina Bell, Phillipa J. Lamont, André Travessa, Juliette Dupont, Lurdes Sampaio, Jérôme Dulon, Sandrine Vuillaumier-Barrot, Sandra Whalen, Arnaud Isapof, Tanya Stojkovic, Susana Quijano-Roy, Gorjana Robevska, Jocelyn van den Bergen, Chloe Hanna, Andrea Simpson, Katie Ayers, David R. Thorburn, John Christodoulou, Philippe Touraine, and Andrew H. Sinclair. Genomic sequencing highlights the diverse molecular causes of perrault syndrome: a peroxisomal disorder (pex6), metabolic disorders (clpp, ggps1), and mtdna maintenance/translation disorders (lars2, tfam). Human Genetics, 139:1325-1343, May 2020. URL: https://doi.org/10.1007/s00439-020-02176-w, doi:10.1007/s00439-020-02176-w. This article has 48 citations and is from a peer-reviewed journal.
(oziebło2020twonovelpathogenic pages 3-5): Dominika Oziębło, Joanna Pazik, Iwona Stępniak, Henryk Skarżyński, and Monika Ołdak. Two novel pathogenic variants confirm rmnd1 causative role in perrault syndrome with renal involvement. Genes, 11:1060, Sep 2020. URL: https://doi.org/10.3390/genes11091060, doi:10.3390/genes11091060. This article has 30 citations.
(kline2022integralroleof pages 5-8): Brianna L. Kline, Sylvie Jaillard, Katrina M. Bell, Shabnam Bakhshalizadeh, Gorjana Robevska, Jocelyn van den Bergen, Jérôme Dulon, Katie L. Ayers, John Christodoulou, Michel C. Tchan, Philippe Touraine, Andrew H. Sinclair, and Elena J. Tucker. Integral role of the mitochondrial ribosome in supporting ovarian function: mrps7 variants in syndromic premature ovarian insufficiency. Genes, 13:2113, Nov 2022. URL: https://doi.org/10.3390/genes13112113, doi:10.3390/genes13112113. This article has 18 citations.
(smith2025biallelicvariantsin pages 15-16): Thomas B. Smith, Robert Kopajtich, Leigh A.M. Demain, Alessandro Rea, Huw B. Thomas, Manuel Schiff, Christian Beetz, Shelagh Joss, Gerard S. Conway, Anju Shukla, Mayuri Yeole, Periyasamy Radhakrishnan, Hatem Azzouz, Amel Ben Chehida, Monique Elmaleh-Bergès, Ruth I.C. Glasgow, Kyle Thompson, Monika Oláhová, Langping He, Emma M. Jenkinson, Amir Jahic, Inna A. Belyantseva, Melanie Barzik, Jill E. Urquhart, James O’Sullivan, Simon G. Williams, Sanjeev S. Bhaskar, Samantha Carrera, Alexander J.M. Blakes, Siddharth Banka, Wyatt W. Yue, Jamie M. Ellingford, Henry Houlden, Kevin J. Munro, Thomas B. Friedman, Robert W. Taylor, Holger Prokisch, Raymond T. O’Keefe, and William G. Newman. Bi-allelic variants in dap3 result in reduced assembly of the mitoribosomal small subunit with altered apoptosis and a perrault-syndrome-spectrum phenotype. Jan 2025. URL: https://doi.org/10.1016/j.ajhg.2024.11.007, doi:10.1016/j.ajhg.2024.11.007. This article has 11 citations.

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Classifications

Inheritance

Subtypes

Pathophysiology

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Phenotypes

Genetic Associations

Medical Actions

Biochemical Markers

Diagnosis

Prevalence

Differential Diagnoses

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References & Deep Research

References

Deep Research

Perrault Syndrome: Disease-Characteristics Research Report

Executive summary

1. Disease information

Definition and terminology

Identifiers

Evidence provenance

2. Etiology, risk, protective factors, and gene–environment interaction

Primary cause

Genetic risk factors

Environmental, lifestyle, and infectious risks

Gene–environment interaction

3. Phenotypes

4. Genetic and molecular information

Variant characteristics

Modifier and epigenetic information

5. Environmental information

6. Mechanism and pathophysiology

Unifying causal chain

Upstream molecular modules

Downstream processes and tissue injury

Molecular profiling and recent research

Suggested GO and Cell Ontology annotations

7. Anatomical structures affected

Primary anatomy

Secondary/genotype-specific anatomy

Localization and lateralization

8. Temporal development

9. Inheritance and population

Epidemiology

Inheritance characteristics

10. Diagnostics

Clinical recognition

Clinical testing

Genetic-testing strategy

Differential diagnosis

Screening

11. Outcome and prognosis

12. Treatment and real-world implementation

Hearing management

Endocrine, bone and reproductive care

Neurologic and multisystem management

Advanced/experimental therapies and trials

13. Prevention

Primary prevention

Secondary prevention

Tertiary prevention

14. Other species and natural disease

15. Model organisms and experimental systems

CLPP-null mouse

Fungal CLPP-null model

Patient fibroblasts and rescue systems

Key recent developments, 2023–2024

Selected exact abstract quotations and source metadata

Evidence limitations

Artifacts