PHARC syndrome is an autosomal recessive neurodegenerative disorder caused by biallelic ABHD12 loss of function. The syndrome combines polyneuropathy, hearing loss, ataxia, retinitis pigmentosa, and cataract, reflecting progressive involvement of peripheral nerves, retina, auditory pathways, and cerebellar systems. Current mechanistic models implicate dysregulated lysophosphatidylserine metabolism and lipid-driven neuroinflammation.
Ask a research question about PHARC syndrome. OpenScientist will conduct autonomous deep research using the Disorder Mechanisms Knowledge Base and PubMed literature (typically 10-30 minutes).
Do not include personal health information in your question. Questions and results are cached in your browser's local storage.
Conditions with similar clinical presentations that must be differentiated from PHARC syndrome:
name: PHARC syndrome
creation_date: '2026-04-13T04:00:00Z'
updated_date: '2026-05-18T22:22:02Z'
description: >-
PHARC syndrome is an autosomal recessive neurodegenerative disorder caused by
biallelic ABHD12 loss of function. The syndrome combines polyneuropathy,
hearing loss, ataxia, retinitis pigmentosa, and cataract, reflecting
progressive involvement of peripheral nerves, retina, auditory pathways, and
cerebellar systems. Current mechanistic models implicate dysregulated
lysophosphatidylserine metabolism and lipid-driven neuroinflammation.
category: Mendelian
parents:
- hereditary disease
- neurodegenerative disease
disease_term:
preferred_term: PHARC syndrome
term:
id: MONDO:0012984
label: PHARC syndrome
pathophysiology:
- name: ABHD12 loss of lipid hydrolase activity
description: >-
Biallelic ABHD12 deficiency impairs degradation of bioactive lysophosphatidylserine
and related oxidized phospholipids.
genes:
- preferred_term: ABHD12
term:
id: hgnc:15868
label: ABHD12
cell_types:
- preferred_term: microglial cell
term:
id: CL:0000129
label: microglial cell
molecular_functions:
- preferred_term: lysophospholipase A1 activity
modifier: DECREASED
term:
id: GO:0120558
label: lysophospholipase A1 activity
biological_processes:
- preferred_term: lipid catabolic process
modifier: ABNORMAL
term:
id: GO:0016042
label: lipid catabolic process
- preferred_term: phospholipid metabolic process
modifier: ABNORMAL
term:
id: GO:0006644
label: phospholipid metabolic process
chemical_entities:
- preferred_term: lysophosphatidylserine
term:
id: CHEBI:68510
label: lysophosphatidylserine
modifier: INCREASED
evidence:
- reference: PMID:34573385
reference_title: "The Phenotypic Spectrum of Patients with PHARC Syndrome Due to Variants in ABHD12: An Ophthalmic Perspective."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
This study investigated the phenotypic spectrum of PHARC (polyneuropathy, hearing loss, ataxia, retinitis pigmentosa and early-onset cataract) syndrome caused by biallelic variants in the ABHD12 gene.
explanation: This directly supports ABHD12 loss as the initiating cause of PHARC syndrome.
- reference: PMID:23297193
reference_title: ABHD12 controls brain lysophosphatidylserine pathways that are deregulated in a murine model of the neurodegenerative disease PHARC.
supports: SUPPORT
evidence_source: IN_VITRO
snippet: "We confirm that recombinant ABHD12 protein exhibits robust LPS lipase activity"
explanation: Recombinant protein evidence supports ABHD12 lysophosphatidylserine lipase activity.
- reference: PMID:23297193
reference_title: ABHD12 controls brain lysophosphatidylserine pathways that are deregulated in a murine model of the neurodegenerative disease PHARC.
supports: SUPPORT
evidence_source: MODEL_ORGANISM
snippet: "which is also substantially reduced in ABHD12(-/-) brain tissue."
explanation: Mouse brain tissue evidence supports reduced ABHD12 LPS lipase activity when ABHD12 is lost.
downstream:
- target: Abnormal lysophosphatidylserine signaling
description: Lipid substrate accumulation perturbs immune and neural homeostasis.
causal_link_type: DIRECT
evidence:
- reference: PMID:23297193
reference_title: ABHD12 controls brain lysophosphatidylserine pathways that are deregulated in a murine model of the neurodegenerative disease PHARC.
supports: SUPPORT
evidence_source: MODEL_ORGANISM
snippet: "where disruption of ABHD12 causes deregulated LPS metabolism and the accumulation of proinflammatory lipids"
explanation: The ABHD12 knockout model links ABHD12 disruption directly to deregulated LPS metabolism and proinflammatory lipid accumulation.
- name: Abnormal lysophosphatidylserine signaling
description: >-
Disordered lysophospholipid handling is thought to drive inflammatory and
degenerative injury in nervous system tissues.
cell_types:
- preferred_term: microglial cell
term:
id: CL:0000129
label: microglial cell
biological_processes:
- preferred_term: phospholipid metabolic process
modifier: ABNORMAL
term:
id: GO:0006644
label: phospholipid metabolic process
- preferred_term: inflammatory response
modifier: INCREASED
term:
id: GO:0006954
label: inflammatory response
- preferred_term: toll-like receptor 2 signaling pathway
modifier: INCREASED
term:
id: GO:0034134
label: toll-like receptor 2 signaling pathway
chemical_entities:
- preferred_term: lysophosphatidylserine
term:
id: CHEBI:68510
label: lysophosphatidylserine
modifier: INCREASED
evidence:
- reference: PMID:23297193
reference_title: ABHD12 controls brain lysophosphatidylserine pathways that are deregulated in a murine model of the neurodegenerative disease PHARC.
supports: SUPPORT
evidence_source: MODEL_ORGANISM
snippet: >-
Taken together, our data provide a molecular model for PHARC, where disruption of ABHD12 causes deregulated LPS metabolism and the accumulation of proinflammatory lipids that promote microglial and neurobehavioral abnormalities.
explanation: This directly supports dysregulated lysophosphatidylserine metabolism as a downstream consequence of ABHD12 loss in a PHARC model.
- reference: PMID:23297193
reference_title: ABHD12 controls brain lysophosphatidylserine pathways that are deregulated in a murine model of the neurodegenerative disease PHARC.
supports: PARTIAL
evidence_source: MODEL_ORGANISM
snippet: "ABHD12(-/-) mice display massive increases in a rare set of very long chain LPS lipids that have been previously reported as Toll-like receptor 2 activators."
explanation: The ABHD12 mouse model supports accumulation of LPS species with reported TLR2-activating properties, providing a plausible innate-immune bridge to microglial activation.
downstream:
- target: Microglial activation and neuroinflammation
description: >-
Accumulated proinflammatory LPS lipids promote microglial activation and
neurobehavioral abnormalities in the ABHD12-deficient brain model.
causal_link_type: DIRECT
evidence:
- reference: PMID:23297193
reference_title: ABHD12 controls brain lysophosphatidylserine pathways that are deregulated in a murine model of the neurodegenerative disease PHARC.
supports: SUPPORT
evidence_source: MODEL_ORGANISM
snippet: "the accumulation of proinflammatory lipids that promote microglial and neurobehavioral abnormalities."
explanation: The model directly connects accumulated proinflammatory LPS lipids to microglial and neurobehavioral abnormalities.
- target: Ophthalmic involvement
description: >-
Human PHARC includes retinal/macular disease and early-onset cataract,
although the exact lipid-mediated ocular intermediates are not resolved
by cached abstract evidence.
causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
evidence:
- reference: PMID:34573385
reference_title: "The Phenotypic Spectrum of Patients with PHARC Syndrome Due to Variants in ABHD12: An Ophthalmic Perspective."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: "Different types of cataract were observed in 13 out of 15 patients (87%), which also included congenital forms of cataract."
explanation: The human cohort documents cataract as a frequent ocular manifestation of ABHD12-related PHARC.
- name: Microglial activation and neuroinflammation
description: >-
In ABHD12-deficient brain, elevated lysophosphatidylserine lipids precede
age-dependent microglial activation and neurobehavioral abnormalities.
cell_types:
- preferred_term: microglial cell
term:
id: CL:0000129
label: microglial cell
biological_processes:
- preferred_term: inflammatory response
modifier: INCREASED
term:
id: GO:0006954
label: inflammatory response
evidence:
- reference: PMID:23297193
reference_title: ABHD12 controls brain lysophosphatidylserine pathways that are deregulated in a murine model of the neurodegenerative disease PHARC.
supports: SUPPORT
evidence_source: MODEL_ORGANISM
snippet: "Notably, elevations in brain LPS lipids in ABHD12(-/-) mice occur early in life (2-6 mo) and are followed by age-dependent increases in microglial activation and auditory and motor defects that resemble the behavioral phenotypes of human PHARC patients."
explanation: The ABHD12 knockout model places microglial activation downstream of early LPS lipid elevation.
downstream:
- target: Progressive multisystem neurodegeneration
description: >-
Microglial activation and neuroinflammatory lipid signaling contribute to
auditory and motor abnormalities resembling PHARC.
causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
evidence:
- reference: PMID:23297193
reference_title: ABHD12 controls brain lysophosphatidylserine pathways that are deregulated in a murine model of the neurodegenerative disease PHARC.
supports: SUPPORT
evidence_source: MODEL_ORGANISM
snippet: "are followed by age-dependent increases in microglial activation and auditory and motor defects that resemble the behavioral phenotypes of human PHARC patients."
explanation: Model evidence links microglial activation to later auditory and motor defects resembling human PHARC.
- name: Progressive multisystem neurodegeneration
description: >-
Chronic neurodegenerative injury contributes to the characteristic
combination of neuropathy, ataxia, hearing loss, and retinal degeneration.
evidence:
- reference: PMID:23297193
reference_title: ABHD12 controls brain lysophosphatidylserine pathways that are deregulated in a murine model of the neurodegenerative disease PHARC.
supports: PARTIAL
evidence_source: MODEL_ORGANISM
snippet: >-
Notably, elevations in brain LPS lipids in ABHD12(-/-) mice occur early in life (2-6 mo) and are followed by age-dependent increases in microglial activation and auditory and motor defects that resemble the behavioral phenotypes of human PHARC patients.
explanation: This supports age-dependent neurodegenerative progression downstream of ABHD12 loss in a PHARC model, while the full human multisystem trajectory is inferred across clinical domains.
downstream:
- target: Peripheral nerve degeneration
description: Peripheral nerve degeneration contributes to sensory and motor deficits.
causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
evidence:
- reference: PMID:34573385
reference_title: "The Phenotypic Spectrum of Patients with PHARC Syndrome Due to Variants in ABHD12: An Ophthalmic Perspective."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: "This study investigated the phenotypic spectrum of PHARC (polyneuropathy, hearing loss, ataxia, retinitis pigmentosa and early-onset cataract) syndrome caused by biallelic variants in the ABHD12 gene."
explanation: The human cohort defines polyneuropathy as a core PHARC manifestation downstream of ABHD12 disease.
- target: Cerebellar degeneration
description: Cerebellar dysfunction causes progressive gait and coordination impairment.
causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
evidence:
- reference: PMID:34573385
reference_title: "The Phenotypic Spectrum of Patients with PHARC Syndrome Due to Variants in ABHD12: An Ophthalmic Perspective."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: "This study investigated the phenotypic spectrum of PHARC (polyneuropathy, hearing loss, ataxia, retinitis pigmentosa and early-onset cataract) syndrome caused by biallelic variants in the ABHD12 gene."
explanation: The human cohort defines ataxia as a core PHARC manifestation downstream of ABHD12 disease.
- target: Auditory pathway degeneration
description: >-
Auditory-system involvement contributes to the hearing-loss component of
PHARC syndrome.
causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
evidence:
- reference: PMID:23297193
reference_title: ABHD12 controls brain lysophosphatidylserine pathways that are deregulated in a murine model of the neurodegenerative disease PHARC.
supports: PARTIAL
evidence_source: MODEL_ORGANISM
snippet: "are followed by age-dependent increases in microglial activation and auditory and motor defects that resemble the behavioral phenotypes of human PHARC patients."
explanation: The ABHD12 knockout model supports auditory defects downstream of lipid elevation and microglial activation.
- name: Ophthalmic involvement
description: >-
PHARC has prominent ophthalmic involvement with retinal/macular degeneration
and cataract; onset and severity are variable across affected individuals.
evidence:
- reference: PMID:34573385
reference_title: "The Phenotypic Spectrum of Patients with PHARC Syndrome Due to Variants in ABHD12: An Ophthalmic Perspective."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: "From an ophthalmic perspective, clinical manifestations in patients with PHARC demonstrate variability with regard to their onset and severity."
explanation: The cohort directly supports variable ophthalmic involvement in PHARC.
downstream:
- target: Retinal degeneration
description: Retinal and macular degeneration produce the rod-cone dystrophy component.
causal_link_type: DIRECT
evidence:
- reference: PMID:34573385
reference_title: "The Phenotypic Spectrum of Patients with PHARC Syndrome Due to Variants in ABHD12: An Ophthalmic Perspective."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: "Fundus examination revealed macular involvement in all patients, ranging from alterations of the retinal pigment epithelium to macular atrophy."
explanation: The human cohort documents retinal and macular involvement in all patients.
- target: Cataract
description: >-
Lens opacity produces the cataract component of PHARC.
causal_link_type: DIRECT
evidence:
- reference: PMID:34573385
reference_title: "The Phenotypic Spectrum of Patients with PHARC Syndrome Due to Variants in ABHD12: An Ophthalmic Perspective."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: "Different types of cataract were observed in 13 out of 15 patients (87%), which also included congenital forms of cataract."
explanation: The human cohort documents cataract as a frequent ocular phenotype in PHARC.
- name: Peripheral nerve degeneration
description: >-
Progressive peripheral nerve injury contributes to the polyneuropathy
component of PHARC syndrome.
downstream:
- target: Peripheral neuropathy
description: Peripheral nerve degeneration is expressed clinically as polyneuropathy.
causal_link_type: DIRECT
evidence:
- reference: PMID:34573385
reference_title: "The Phenotypic Spectrum of Patients with PHARC Syndrome Due to Variants in ABHD12: An Ophthalmic Perspective."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: "This study investigated the phenotypic spectrum of PHARC (polyneuropathy, hearing loss, ataxia, retinitis pigmentosa and early-onset cataract) syndrome caused by biallelic variants in the ABHD12 gene."
explanation: The human cohort directly identifies polyneuropathy as a core component of PHARC.
- name: Cerebellar degeneration
description: >-
Progressive cerebellar involvement contributes to gait instability and
ataxia.
downstream:
- target: Ataxia
description: Cerebellar degeneration is expressed clinically as ataxia.
causal_link_type: DIRECT
evidence:
- reference: PMID:34573385
reference_title: "The Phenotypic Spectrum of Patients with PHARC Syndrome Due to Variants in ABHD12: An Ophthalmic Perspective."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: "This study investigated the phenotypic spectrum of PHARC (polyneuropathy, hearing loss, ataxia, retinitis pigmentosa and early-onset cataract) syndrome caused by biallelic variants in the ABHD12 gene."
explanation: The human cohort directly identifies ataxia as a core component of PHARC.
- name: Auditory pathway degeneration
description: >-
Progressive auditory-system involvement contributes to the sensorineural
hearing-loss component of PHARC syndrome.
evidence:
- reference: PMID:23297193
reference_title: ABHD12 controls brain lysophosphatidylserine pathways that are deregulated in a murine model of the neurodegenerative disease PHARC.
supports: PARTIAL
evidence_source: MODEL_ORGANISM
snippet: "Notably, elevations in brain LPS lipids in ABHD12(-/-) mice occur early in life (2-6 mo) and are followed by age-dependent increases in microglial activation and auditory and motor defects that resemble the behavioral phenotypes of human PHARC patients."
explanation: The ABHD12 knockout model supports age-dependent auditory defects resembling human PHARC.
- reference: PMID:34573385
reference_title: "The Phenotypic Spectrum of Patients with PHARC Syndrome Due to Variants in ABHD12: An Ophthalmic Perspective."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: "This study investigated the phenotypic spectrum of PHARC (polyneuropathy, hearing loss, ataxia, retinitis pigmentosa and early-onset cataract) syndrome caused by biallelic variants in the ABHD12 gene."
explanation: The human cohort defines hearing loss as a core PHARC manifestation.
downstream:
- target: Sensorineural hearing impairment
description: Auditory pathway degeneration is expressed clinically as sensorineural hearing impairment.
causal_link_type: DIRECT
evidence:
- reference: PMID:34573385
reference_title: "The Phenotypic Spectrum of Patients with PHARC Syndrome Due to Variants in ABHD12: An Ophthalmic Perspective."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: "This study investigated the phenotypic spectrum of PHARC (polyneuropathy, hearing loss, ataxia, retinitis pigmentosa and early-onset cataract) syndrome caused by biallelic variants in the ABHD12 gene."
explanation: The human cohort directly identifies hearing loss as a core component of PHARC.
- name: Retinal degeneration
description: >-
Retinal and macular degeneration contribute to the retinitis pigmentosa
phenotype.
evidence:
- reference: PMID:34573385
reference_title: "The Phenotypic Spectrum of Patients with PHARC Syndrome Due to Variants in ABHD12: An Ophthalmic Perspective."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Fundus examination revealed macular involvement in all patients, ranging from alterations of the retinal pigment epithelium to macular atrophy.
explanation: This directly supports retinal degenerative involvement in PHARC syndrome.
downstream:
- target: Retinitis pigmentosa
description: Retinal degeneration is expressed clinically as rod-cone dystrophy/retinitis pigmentosa.
causal_link_type: DIRECT
evidence:
- reference: PMID:34573385
reference_title: "The Phenotypic Spectrum of Patients with PHARC Syndrome Due to Variants in ABHD12: An Ophthalmic Perspective."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: "Fundus examination revealed macular involvement in all patients, ranging from alterations of the retinal pigment epithelium to macular atrophy."
explanation: The cohort documents retinal and macular involvement supporting the retinitis pigmentosa phenotype.
phenotypes:
- name: Peripheral neuropathy
category: Neurologic
description: Length-dependent neuropathy is a core and often early manifestation.
phenotype_term:
preferred_term: Peripheral neuropathy
term:
id: HP:0009830
label: Peripheral neuropathy
evidence:
- reference: PMID:34573385
reference_title: "The Phenotypic Spectrum of Patients with PHARC Syndrome Due to Variants in ABHD12: An Ophthalmic Perspective."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
This study investigated the phenotypic spectrum of PHARC (polyneuropathy, hearing loss, ataxia, retinitis pigmentosa and early-onset cataract) syndrome caused by biallelic variants in the ABHD12 gene.
explanation: This directly supports peripheral neuropathy as part of the defining PHARC acronym.
- name: Sensorineural hearing impairment
category: Otolaryngologic
description: Progressive hearing impairment contributes substantially to disability.
phenotype_term:
preferred_term: Sensorineural hearing impairment
term:
id: HP:0000407
label: Sensorineural hearing impairment
evidence:
- reference: PMID:34573385
reference_title: "The Phenotypic Spectrum of Patients with PHARC Syndrome Due to Variants in ABHD12: An Ophthalmic Perspective."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
This study investigated the phenotypic spectrum of PHARC (polyneuropathy, hearing loss, ataxia, retinitis pigmentosa and early-onset cataract) syndrome caused by biallelic variants in the ABHD12 gene.
explanation: This directly supports hearing loss as part of the defining PHARC syndrome phenotype.
- name: Ataxia
category: Neurologic
description: Cerebellar involvement causes progressive gait instability and dyscoordination.
phenotype_term:
preferred_term: Ataxia
term:
id: HP:0001251
label: Ataxia
evidence:
- reference: PMID:34573385
reference_title: "The Phenotypic Spectrum of Patients with PHARC Syndrome Due to Variants in ABHD12: An Ophthalmic Perspective."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
This study investigated the phenotypic spectrum of PHARC (polyneuropathy, hearing loss, ataxia, retinitis pigmentosa and early-onset cataract) syndrome caused by biallelic variants in the ABHD12 gene.
explanation: This directly supports ataxia as a defining component of PHARC syndrome.
- name: Retinitis pigmentosa
category: Ophthalmologic
description: Retinal dystrophy causes night blindness and progressive visual loss.
phenotype_term:
preferred_term: Retinitis pigmentosa
term:
id: HP:0000510
label: Rod-cone dystrophy
evidence:
- reference: PMID:34573385
reference_title: "The Phenotypic Spectrum of Patients with PHARC Syndrome Due to Variants in ABHD12: An Ophthalmic Perspective."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Fundus examination revealed macular involvement in all patients, ranging from alterations of the retinal pigment epithelium to macular atrophy.
explanation: This directly supports retinal degenerative disease within the PHARC phenotype.
- name: Cataract
category: Ophthalmologic
description: Lens opacity is part of the canonical PHARC acronym and phenotype.
phenotype_term:
preferred_term: Cataract
term:
id: HP:0000518
label: Cataract
evidence:
- reference: PMID:34573385
reference_title: "The Phenotypic Spectrum of Patients with PHARC Syndrome Due to Variants in ABHD12: An Ophthalmic Perspective."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Different types of cataract were observed in 13 out of 15 patients (87%), which also included congenital forms of cataract.
explanation: This directly supports cataract as a common PHARC phenotype.
biochemical:
- name: Brain lysophosphatidylserine lipids
biomarker_term:
preferred_term: lysophosphatidylserine
term:
id: CHEBI:68510
label: lysophosphatidylserine
presence: INCREASED
context: >-
Elevated brain lysophosphatidylserine lipids are a model-system biochemical
readout of ABHD12 loss and dysregulated LPS metabolism.
readouts:
- target: Abnormal lysophosphatidylserine signaling
relationship: READOUT_OF
direction: POSITIVE
interpretation: >-
Increased LPS lipids report the lipid-metabolism abnormality downstream
of ABHD12 loss in the PHARC model.
evidence:
- reference: PMID:23297193
reference_title: ABHD12 controls brain lysophosphatidylserine pathways that are deregulated in a murine model of the neurodegenerative disease PHARC.
supports: SUPPORT
evidence_source: MODEL_ORGANISM
snippet: "ABHD12(-/-) mice display massive increases in a rare set of very long chain LPS lipids"
explanation: The ABHD12 knockout mouse metabolomics result directly supports increased LPS lipids as a biochemical readout.
evidence:
- reference: PMID:23297193
reference_title: ABHD12 controls brain lysophosphatidylserine pathways that are deregulated in a murine model of the neurodegenerative disease PHARC.
supports: SUPPORT
evidence_source: MODEL_ORGANISM
snippet: "ABHD12(-/-) mice display massive increases in a rare set of very long chain LPS lipids"
explanation: The mouse model directly identifies increased brain LPS lipids after ABHD12 loss.
genetic:
- name: ABHD12
gene_term:
preferred_term: ABHD12
term:
id: hgnc:15868
label: ABHD12
association: Causal biallelic loss-of-function variant
evidence:
- reference: PMID:34573385
reference_title: "The Phenotypic Spectrum of Patients with PHARC Syndrome Due to Variants in ABHD12: An Ophthalmic Perspective."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
This study investigated the phenotypic spectrum of PHARC (polyneuropathy, hearing loss, ataxia, retinitis pigmentosa and early-onset cataract) syndrome caused by biallelic variants in the ABHD12 gene.
explanation: This directly supports ABHD12 as the causal gene in PHARC syndrome.
- reference: CGGV:assertion_ccd68c20-2024-4239-be51-26697e19a6b4-2018-06-26T160000.000Z
reference_title: "ABHD12 / PHARC syndrome (Definitive)"
supports: SUPPORT
evidence_source: OTHER
snippet: "ABHD12 | HGNC:15868 | PHARC syndrome | MONDO:0012984 | AR | Definitive"
explanation: ClinGen classifies the ABHD12-PHARC syndrome gene-disease relationship as definitive with autosomal recessive inheritance.
environmental: []
treatments:
- name: Supportive multidisciplinary care
treatment_term:
preferred_term: supportive care
term:
id: MAXO:0000950
label: supportive care
description: >-
Management is supportive and includes neurologic, low-vision, audiologic,
and rehabilitation interventions.
target_phenotypes:
- preferred_term: Peripheral neuropathy
term:
id: HP:0009830
label: Peripheral neuropathy
- preferred_term: Ataxia
term:
id: HP:0001251
label: Ataxia
- name: Cataract surgery
treatment_term:
preferred_term: surgical procedure
term:
id: MAXO:0000004
label: surgical procedure
description: >-
Cataract extraction may improve visual function when lens opacity becomes
clinically significant.
target_phenotypes:
- preferred_term: Cataract
term:
id: HP:0000518
label: Cataract
diagnosis:
- name: ABHD12 genetic testing
diagnosis_term:
preferred_term: genetic testing
term:
id: MAXO:0000127
label: genetic testing
description: >-
Molecular diagnosis depends on identifying biallelic pathogenic ABHD12 variants.
results: Biallelic pathogenic ABHD12 variants support the diagnosis of PHARC syndrome.
- name: Ophthalmologic evaluation
diagnosis_term:
preferred_term: clinical assessment
term:
id: MAXO:0000487
label: clinical assessment
description: >-
Retinal imaging and electrophysiology are used to document rod-cone
dystrophy and associated cataract.
results: Rod-cone dystrophy with cataract supports PHARC syndrome.
- name: Audiometric testing
diagnosis_term:
preferred_term: audiometric testing
term:
id: MAXO:0000125
label: audiometric testing
description: >-
Formal hearing assessment documents the sensorineural hearing-loss
component of PHARC syndrome.
results: Sensorineural hearing loss supports PHARC syndrome.
- name: Electromyography and nerve conduction studies
diagnosis_term:
preferred_term: electromyography procedure
term:
id: MAXO:0035091
label: electromyography procedure
description: >-
Peripheral nerve testing helps define the neuropathic burden and
multisystem severity of PHARC syndrome.
results: Peripheral neuropathy supports PHARC syndrome.
differential_diagnoses:
- name: adult Refsum disease
disease_term:
preferred_term: adult Refsum disease
term:
id: MONDO:0009958
label: adult Refsum disease
description: >-
Refsum disease can overlap with retinitis pigmentosa, neuropathy, and ataxia.
- name: Usher syndrome
disease_term:
preferred_term: Usher syndrome
term:
id: MONDO:0019501
label: Usher syndrome
description: >-
Usher syndrome overlaps through retinal degeneration and hearing loss but
lacks the full PHARC neurodegenerative profile.
clinical_trials: []
datasets: []
This report is retrieval-only and is generated directly from Asta results.
search_papers_by_relevance with snippet_search.