Hypoparathyroidism-Deafness-Renal Disease Syndrome

Mendelian MONDO:0007797 Pathograph 38 Show in embeddings browser

Hypoparathyroidism-deafness-renal disease (HDR) syndrome, also called Barakat syndrome, is an autosomal dominant developmental disorder caused by heterozygous loss-of-function variants or whole-gene deletions of GATA3, a dual zinc-finger transcription factor required for development of the parathyroid glands, the cochlea and the kidney. It is defined by the triad of hypoparathyroidism with hypocalcemia, bilateral sensorineural hearing loss and renal disease, which ranges from dysplasia, hypoplasia, agenesis, cysts and vesicoureteral reflux to glomerular disease with proteinuria and progression to end-stage kidney disease in a minority. Penetrance and expressivity of each component are variable, even within one family, and the penetrance of each defect increases with age. Hearing loss is the most constant feature; only about two thirds of reported patients show the complete triad.

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1
Inheritance
9
Pathophys.
23
Phenotypes
38
Pathograph
1
Genes
4
Medical Actions
3
Differentials
1
Models
1
Deep Research
👪

Inheritance

1
Autosomal Dominant HP:0000006
HDR syndrome is inherited as an autosomal dominant trait with variable penetrance of each of its components. Both familial transmission and de novo variants are reported.
Autosomal dominant inheritance
Show evidence (2 references)
PMID:38940299 SUPPORT Human Clinical
"An autosomal dominant disease caused by heterozygous pathogenic GATA3 variants, the penetrance of each associated condition is variable."
States the dominant mode of inheritance and the variable penetrance of each component in a 28-patient cohort combined with a literature review.
PMID:32442337 SUPPORT REVIEW SYNTHESIS Human Clinical
"The hypoparathyroidism, deafness, and renal dysplasia (HDR) syndrome is an autosomal dominant disorder caused by heterozygous mutations of the GATA3 gene."
Review of all reported families restating the autosomal dominant inheritance of heterozygous GATA3 variants.
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Pathophysiology

9
GATA3 Haploinsufficiency
Heterozygous GATA3 variants (frameshift, nonsense, splice-site, missense and whole-gene deletions) halve the dose of functional GATA3. Over 90% of characterized variants abolish DNA binding by removing or disrupting the C-terminal zinc finger; missense variants cluster in the two zinc-finger domains and either abolish DNA binding, reduce binding affinity, or, for N-terminal finger variants, disrupt interaction with the cofactor FOG2. Whole-gene deletions produce the same syndrome, which is the primary argument for haploinsufficiency as the mechanism.
Genetic context GATA3 hgnc:4172 HUGO Gene Nomenclature Committee (hgnc) Relation: this genetic context concerns this gene This genetic context concerns GATA3 (hgnc:4172). hgnc:4172 is a gene from the HUGO Gene Nomenclature Committee. variant_origin: GERMLINE zygosity: HETEROZYGOUS functional_impact_category: LOSS_OF_FUNCTION
GATA3 sequence-specific DNA-binding transcription factor activity GO:0003700 Gene Ontology (GO) Relation: this pathophysiological event involves this molecular function This pathophysiological event involves decreased GATA3 sequence-specific DNA-binding transcription factor activity, annotated with DNA-binding transcription factor activity (GO:0003700). GO:0003700 is a molecular function from the Gene Ontology. ↓ DECREASED
Downstream
Reduced GCM2 Expression in Parathyroid Progenitors
Reduced PTH Gene Transactivation
Cochlear Outer Hair Cell Degeneration
Dysregulated Nephric Duct and Ureteric Bud Development
Mesangial Cell Precursor Deficiency
Show evidence (4 references)
PMID:10935639 SUPPORT Human Clinical
"Investigation for GATA3 mutations in three other HDR probands identified one nonsense mutation and two intragenic deletions that predicted a loss of function, as confirmed by absence of DNA binding by the mutant GATA3 protein."
The gene-discovery study: deletion mapping plus loss-of-function point variants establish GATA3 haploinsufficiency as the cause of HDR.
PMID:17210674 SUPPORT In Vitro
"Electrophoretic mobility shift assays (EMSAs) revealed three classes of GATA3 mutations: those that lead to a loss of DNA binding which represent over 90% of all mutations, and involved a loss of the carboxy-terminal zinc finger"
Functional assays showing that the large majority of HDR alleles abolish DNA binding, the molecular basis of the dosage loss.
PMID:14985365 SUPPORT In Vitro
"Mutations involving GATA3 ZnF2 or adjacent basic amino acids resulted in a loss of DNA binding, but those of ZnF1 either lead to a loss of interaction with specific FOG2 ZnFs or altered DNA-binding affinity."
Distinguishes the two functional classes of zinc-finger variants summarized in the node description.
+ 1 more reference
Reduced GCM2 Expression in Parathyroid Progenitors
GATA3 binds a double-GATA motif in the promoter of GCM2 (GCMB), the parathyroid-specific transcription factor, and is required for its expression in the third pharyngeal pouch. Halving GATA3 dose reduces the number of GCM2-expressing parathyroid progenitors.
parathyroid chief cell progenitor CL:0000446 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves parathyroid chief cell progenitor, annotated with chief cell of parathyroid gland (CL:0000446). CL:0000446 is a cell type from the Cell Ontology.
parathyroid gland development GO:0060017 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves decreased parathyroid gland development (GO:0060017). GO:0060017 is a biological process from the Gene Ontology. ↓ DECREASED
Downstream
Parathyroid Gland Hypoplasia
Show evidence (2 references)
PMID:20484821 SUPPORT In Vitro
"Electrophoretic mobility shift, luciferase reporter, and chromatin immunoprecipitation assays showed that GATA3 binds specifically to a functional double-GATA motif within the GCMB promoter."
Direct binding of GATA3 to the GCMB promoter places GCM2 downstream of GATA3.
PMID:20484821 SUPPORT Model Organism
"At E11.5, Gata3+/- embryos had smaller parathyroid-thymus primordia with fewer cells expressing the parathyroid-specific gene glial cells missing 2 (Gcm2), the homolog of human GCMB."
Heterozygous mouse embryos, the genetic equivalent of HDR, have fewer Gcm2-expressing parathyroid progenitors.
Parathyroid Gland Hypoplasia
Reduced specification and survival of parathyroid progenitors leaves smaller parathyroid glands with reduced proliferative capacity, which cannot mount an adequate response to hypocalcemic challenge.
parathyroid gland UBERON:0001132 Uberon multi-species anatomy ontology (UBERON) Relation: this pathophysiological event occurs in this anatomical location This pathophysiological event occurs in parathyroid gland (UBERON:0001132). UBERON:0001132 is an anatomical location from the Uberon multi-species anatomy ontology.
Animal models
Gata3 heterozygous knockout mouse Mouse recapitulates
Downstream
Deficient Parathyroid Hormone Secretion
Show evidence (1 reference)
PMID:20484821 SUPPORT Model Organism
"Compared with their wild-type littermates, Gata3+/- mice had lower plasma concentrations of calcium and parathyroid hormone (PTH) and smaller parathyroid glands with a reduced Ki-67 proliferation rate."
Gata3 heterozygous mice have hypoplastic, hypoproliferative parathyroids together with low PTH and calcium.
Reduced PTH Gene Transactivation
In addition to its developmental role, GATA3 cooperates with GCM2, MAFB and SP1 to activate the parathyroid hormone gene promoter. HDR-associated GATA3 mutants fail to activate the PTH promoter, so PTH output per parathyroid cell may also be reduced.
GATA3-dependent activation of PTH transcription GO:0045944 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves decreased GATA3-dependent activation of PTH transcription, annotated with positive regulation of transcription by RNA polymerase II (GO:0045944). GO:0045944 is a biological process from the Gene Ontology. ↓ DECREASED
Downstream
Deficient Parathyroid Hormone Secretion
Show evidence (2 references)
PMID:25917456 SUPPORT In Vitro
"Gata3 interacted with Gcm2 and MafB, two known transcriptional regulators of parathyroid development, and synergistically stimulated the PTH promoter."
Places GATA3 directly on the PTH promoter as a co-activator.
PMID:25917456 SUPPORT In Vitro
"HDR syndrome-associated Gata3 mutants were defective in activating the PTH promoter."
Disease alleles lose this transactivation function.
Deficient Parathyroid Hormone Secretion
Circulating PTH is low or inappropriately normal for the serum calcium. Loss of PTH action reduces renal calcium reabsorption, bone resorption and renal phosphate excretion, producing hypocalcemia with hyperphosphatemia and, in treated patients, hypercalciuria.
parathyroid hormone secretion GO:0035898 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves decreased parathyroid hormone secretion (GO:0035898). GO:0035898 is a biological process from the Gene Ontology. ↓ DECREASED
Downstream
Hypoparathyroidism
Decreased circulating parathyroid hormone level
Hypocalcemia
Hyperphosphatemia
Hypomagnesemia
Hypercalciuria
Basal ganglia calcification
Show evidence (1 reference)
PMID:31660939 SUPPORT Human Clinical
"Biochemical investigations showed persistent low serum corrected calcium levels with hyperphosphataemia, hypomagnesaemia, low parathyroid hormone levels, hypercalciuria, and low total 25-hydroxy vitamin D levels."
The biochemical profile of PTH deficiency in a patient with a GATA3 whole-gene deletion.
Cochlear Outer Hair Cell Degeneration
The hearing loss of HDR is peripheral (cochlear) rather than central. In Gata3 heterozygous mice, degeneration starts in the outer hair cells at the cochlear apex and progresses to involve all hair cells and supporting cells; otoacoustic emissions deteriorate rapidly and outer hair cells accumulate vacuoles. Psychophysical testing in HDR patients shows the signature of outer hair cell loss. Complete loss of Gata3 in the developing inner ear additionally abolishes prosensory specification and depletes spiral ganglion neurons, showing that the gene is required at several steps of cochlear development.
cochlear outer hair cell CL:0000601 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves cochlear outer hair cell (CL:0000601). CL:0000601 is a cell type from the Cell Ontology.
cochlea development GO:0090102 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves decreased cochlea development (GO:0090102). GO:0090102 is a biological process from the Gene Ontology. ↓ DECREASED
cochlea UBERON:0001844 Uberon multi-species anatomy ontology (UBERON) Relation: this pathophysiological event occurs in this anatomical location This pathophysiological event occurs in cochlea (UBERON:0001844). UBERON:0001844 is an anatomical location from the Uberon multi-species anatomy ontology.
Animal models
Gata3 heterozygous knockout mouse Mouse recapitulates
Downstream
Bilateral sensorineural hearing impairment
Show evidence (5 references)
PMID:15207274 SUPPORT Model Organism
"cochleae of heterozygous Gata3 mice showed significant progressive morphological degeneration starting with the outer hair cells (OHCs) at the apex and ultimately affecting all hair cells and supporting cells in the entire cochlea"
Localizes the auditory lesion of Gata3 haploinsufficiency to cochlear hair cells, beginning with the outer hair cells.
PMID:15994092 SUPPORT Model Organism
"Together, these findings indicate that outer hair cell malfunctioning plays a major role in the hearing loss in HDR-syndrome."
Functional (DPOAE) and ultrastructural evidence for outer hair cell failure in the heterozygous mouse.
PMID:24434941 SUPPORT Human Clinical
"Overall, the results of the psychophysical measurements indicated characteristics of outer hair cell loss."
Human psychophysical data consistent with the outer hair cell mechanism seen in mice.
+ 2 more references
Dysregulated Nephric Duct and Ureteric Bud Development
GATA3 is expressed in the nephric (Wolffian) duct downstream of PAX2/PAX8 and beta-catenin and upstream of RET. Its loss causes premature nephric duct differentiation, loss of RET expression and ectopic ureteric budding, producing a spectrum of congenital anomalies of the kidney and urinary tract (renal adysplasia, duplex systems, hydroureter) and of the genital tract derived from the same primordia. This is the proposed basis for the dysplastic renal and genital malformations of HDR, although the mouse evidence comes from homozygous or conditional loss rather than heterozygosity.
ureteric bud cell CL:4030066 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves ureteric bud cell (CL:4030066). CL:4030066 is a cell type from the Cell Ontology.
mesonephric duct development GO:0072177 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves abnormal mesonephric duct development (GO:0072177). GO:0072177 is a biological process from the Gene Ontology. ⚠ ABNORMAL ureteric bud development GO:0001657 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves abnormal ureteric bud development (GO:0001657). GO:0001657 is a biological process from the Gene Ontology. ⚠ ABNORMAL
Downstream
Renal dysplasia
Renal hypoplasia
Multicystic kidney dysplasia
Renal cyst
Vesicoureteral reflux
Female genital tract anomaly
Bicornuate uterus
Unilateral renal agenesis
Hydronephrosis
Glomerular Injury and Progressive Nephron Loss Congenitally dysplastic or hypoplastic kidneys start with a reduced nephron complement, one route to later loss of kidney function.
Show evidence (3 references)
PMID:19112489 SUPPORT Model Organism
"Here, we show that the nephric duct-specific inactivation of the transcription factor gene Gata3 leads to massive ectopic ureter budding. This results in a spectrum of urogenital malformations including kidney adysplasia, duplex systems, and hydroureter, as well as vas deferens hyperplasia and..."
Links loss of Gata3 in the nephric duct to renal adysplasia and genital tract malformations resembling human CAKUT.
PMID:19112489 SUPPORT Model Organism
"We show that Gata3 inactivation causes premature nephric duct cell differentiation and loss of Ret receptor gene expression."
Identifies the cellular defect: premature differentiation and loss of RET.
PMID:16319112 SUPPORT Model Organism
"At the molecular level, the nephric duct of Gata3(-/-) embryos is characterized by the loss of Ret expression and signaling"
Independent confirmation that Gata3 is required for RET expression in the nephric duct.
Mesangial Cell Precursor Deficiency
GATA3 is expressed in FOXD1-lineage stromal progenitors that give rise to glomerular mesangial cells and remains expressed in adult mesangial cells. Gata3 heterozygous mice have too few mesangial precursors and glomerular abnormalities, which offers a mechanism for the glomerular disease (mesangioproliferative glomerulonephritis, proteinuria, focal segmental glomerulosclerosis) seen in some HDR patients.
glomerular mesangial cell CL:1000742 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves glomerular mesangial cell (CL:1000742). CL:1000742 is a cell type from the Cell Ontology.
glomerulus development GO:0032835 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves decreased glomerulus development (GO:0032835). GO:0032835 is a biological process from the Gene Ontology. ↓ DECREASED
Animal models
Gata3 heterozygous knockout mouse Mouse recapitulates
Downstream
Glomerular Injury and Progressive Nephron Loss
Show evidence (1 reference)
PMID:31405951 SUPPORT Model Organism
"In mice, we uncover that GATA3 is essential for normal glomerular development, and mice with haploinsufficiency of Gata3 have too few MC precursors and glomerular abnormalities."
Heterozygous Gata3 mice, the genetic equivalent of HDR, have a mesangial precursor deficit and glomerular abnormalities.
Glomerular Injury and Progressive Nephron Loss
Dysplastic or hypoplastic kidneys and glomerular lesions lead in a subset of patients to proteinuria, sometimes in the nephrotic range, focal segmental glomerulosclerosis, and a progressive fall in kidney function. About one in ten reported patients reaches end-stage kidney disease, at ages from adolescence to late adulthood. The renal course is the main determinant of overall prognosis.
kidney UBERON:0002113 Uberon multi-species anatomy ontology (UBERON) Relation: this pathophysiological event occurs in this anatomical location This pathophysiological event occurs in kidney (UBERON:0002113). UBERON:0002113 is an anatomical location from the Uberon multi-species anatomy ontology.
Downstream
Nephrotic range proteinuria
Focal segmental glomerulosclerosis
Stage 5 chronic kidney disease
Show evidence (2 references)
PMID:27387476 SUPPORT Human Clinical
"Three patients displayed nephrotic-range proteinuria and reached end-stage renal disease (ESRD) between the ages of 19 and 61 years, whilst lesions of focal and segmental glomerulosclerosis were histologically demonstrated in one of them."
Documents the glomerular course: nephrotic-range proteinuria, FSGS and ESRD in the same patients.
PMID:31405951 SUPPORT BACKGROUND Human Clinical
"In humans, autosomal dominant GATA3 mutations can cause renal aplasia as part of the hypoparathyroidism, renal dysplasia, deafness (HDR) syndrome that includes mesangioproliferative GN."
Background statement from the mouse study linking HDR to glomerular (mesangioproliferative) disease in patients.
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Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence and cross-linked metadata.
Pathograph: causal mechanism network for Hypoparathyroidism-Deafness-Renal Disease Syndrome Interactive directed graph showing how pathophysiology mechanisms, phenotypes, genetic factors and variants, experimental models, environmental triggers, and treatments relate through causal and linked edges.
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Phenotypes

23
Ear 1
Bilateral sensorineural hearing impairment VERY_FREQUENT HP:0008619 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Bilateral sensorineural hearing impairment (HP:0008619). HP:0008619 is a phenotype from the Human Phenotype Ontology.
Show evidence (3 references)
PMID:32442337 SUPPORT REVIEW SYNTHESIS Human Clinical
"The most frequently observed abnormality was deafness (93%), followed by hypoparathyroidism (87%) and renal defects (61%)."
Deafness is the most frequent component.
PMID:24434941 SUPPORT Human Clinical
"Their hearing impairment was congenital, bilateral and symmetric. Audiograms showed mild-to-moderate hearing impairment with a flat audiogram configuration."
Describes the audiometric phenotype: congenital, bilateral, symmetric.
PMID:27387476 SUPPORT Human Clinical
"Sensorineural deafness was consistently diagnosed, ranging from clinical hearing loss since infancy in seven patients to deafness detected only by audiometry in adulthood in one single patient."
Shows the range of severity and age at detection.
Endocrine 2
Hypoparathyroidism VERY_FREQUENT HP:0000829 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Hypoparathyroidism (HP:0000829). HP:0000829 is a phenotype from the Human Phenotype Ontology.
Show evidence (3 references)
PMID:32442337 SUPPORT REVIEW SYNTHESIS Human Clinical
"The most frequently observed abnormality was deafness (93%), followed by hypoparathyroidism (87%) and renal defects (61%)."
Frequency of hypoparathyroidism across 177 reported patients.
PMID:27387476 SUPPORT REVIEW SYNTHESIS Human Clinical
"Review of 115 previously reported cases of GATA-3 mutations showed hypoparathyroidism and deafness in 95% of patients, and renal abnormalities in only 60%."
Independent literature review with a similar frequency estimate.
PMID:42595857 SUPPORT Human Clinical
"Regarding the classical triad, hypoparathyroidism, deafness, and renal anomalies were observed in 45, 100, and 90% of patients, respectively."
Shows ascertainment dependence: in a kidney disease cohort hypoparathyroidism was present in under half of patients.
Decreased circulating parathyroid hormone level HP:0031817 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Decreased circulating parathyroid hormone level (HP:0031817). HP:0031817 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:31660939 SUPPORT Human Clinical
"Biochemical investigations showed persistent low serum corrected calcium levels with hyperphosphataemia, hypomagnesaemia, low parathyroid hormone levels, hypercalciuria, and low total 25-hydroxy vitamin D levels."
Low PTH documented in a patient with a GATA3 whole-gene deletion.
Genitourinary 14
Hypercalciuria HP:0002150 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Hypercalciuria (HP:0002150). HP:0002150 is a phenotype from the Human Phenotype Ontology.
Sequelae: Nephrocalcinosis
Show evidence (1 reference)
PMID:31660939 SUPPORT Human Clinical
"On screening, his mother was also found to have asymptomatic hypocalcaemia, hypomagnesaemia, hyperphosphataemia, hypercalciuria and low total 25-hydroxy vitamin D levels."
Hypercalciuria documented in an untreated, newly identified affected relative.
Renal dysplasia FREQUENT HP:0000110 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Renal dysplasia (HP:0000110). HP:0000110 is a phenotype from the Human Phenotype Ontology.
Show evidence (2 references)
PMID:27387476 SUPPORT Human Clinical
"Renal abnormalities observed in six patients were diverse and of dysplastic nature."
Dysplastic character of the renal anomalies in a case series.
PMID:32442337 SUPPORT REVIEW SYNTHESIS Human Clinical
"The most frequently observed abnormality was deafness (93%), followed by hypoparathyroidism (87%) and renal defects (61%)."
Frequency of renal defects across reported patients (FREQUENT band).
Renal hypoplasia HP:0000089 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Renal hypoplasia (HP:0000089). HP:0000089 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:26800885 SUPPORT Human Clinical
"her mother had sensorineural deafness, a low serum calcium level (2.1 mmol/l), hypoplastic left kidney, and a past history of an operation for right vesicoureteral reflux"
Hypoplastic kidney in a GATA3 variant carrier with the other HDR features.
Multicystic kidney dysplasia HP:0000003 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Multicystic kidney dysplasia (HP:0000003). HP:0000003 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:37561279 SUPPORT Human Clinical
"his past medical history was remarkable for right nephrectomy at the age of 4 months due to multicystic renal disease"
Multicystic renal disease in infancy in an HDR proband.
Renal cyst HP:0000107 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Renal cyst (HP:0000107). HP:0000107 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:37561279 SUPPORT Human Clinical
"Abdomen ultrasound showed bilateral renal cysts."
Bilateral renal cysts in an HDR proband.
Vesicoureteral reflux HP:0000076 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Vesicoureteral reflux (HP:0000076). HP:0000076 is a phenotype from the Human Phenotype Ontology.
Show evidence (2 references)
PMID:26800885 SUPPORT Human Clinical
"her mother had sensorineural deafness, a low serum calcium level (2.1 mmol/l), hypoplastic left kidney, and a past history of an operation for right vesicoureteral reflux"
Surgically treated vesicoureteral reflux in a GATA3 variant carrier.
PMID:38940299 SUPPORT Human Clinical
"follow up of patients with HDR syndrome should include monitoring of parathyroid function and vesicoureteral reflux in order to prevent complications"
Cohort-based recommendation to monitor vesicoureteral reflux, reflecting its recurrence in HDR.
Unilateral renal agenesis HP:0000122 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Unilateral renal agenesis (HP:0000122). HP:0000122 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:42595857 SUPPORT Human Clinical
"Unilateral kidney agenesis and hydronephrosis were observed in 11.1% (1/9) of patients."
Frequency of unilateral renal agenesis among patients with renal manifestations.
Hydronephrosis HP:0000126 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Hydronephrosis (HP:0000126). HP:0000126 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:42595857 SUPPORT Human Clinical
"Unilateral kidney agenesis and hydronephrosis were observed in 11.1% (1/9) of patients."
Frequency of hydronephrosis among patients with renal manifestations.
Nephrotic range proteinuria HP:0012593 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Nephrotic range proteinuria (HP:0012593). HP:0012593 is a phenotype from the Human Phenotype Ontology.
Show evidence (2 references)
PMID:27387476 SUPPORT Human Clinical
"Three patients displayed nephrotic-range proteinuria and reached end-stage renal disease (ESRD) between the ages of 19 and 61 years, whilst lesions of focal and segmental glomerulosclerosis were histologically demonstrated in one of them."
Nephrotic-range proteinuria in three of eight patients.
PMID:23052618 SUPPORT Human Clinical
"atypical renal symptoms (diffuse proliferative glomerulonephritis characterized by a self-limiting nephrotic syndrome)"
Glomerular nephropathy with nephrotic syndrome in an HDR patient.
Focal segmental glomerulosclerosis HP:0000097 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Focal segmental glomerulosclerosis (HP:0000097). HP:0000097 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:27387476 SUPPORT Human Clinical
"Three patients displayed nephrotic-range proteinuria and reached end-stage renal disease (ESRD) between the ages of 19 and 61 years, whilst lesions of focal and segmental glomerulosclerosis were histologically demonstrated in one of them."
Histologically proven FSGS in one patient.
Nephrocalcinosis HP:0000121 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Nephrocalcinosis (HP:0000121). HP:0000121 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:23052618 SUPPORT Human Clinical
"bilateral sensorineural deafness and renal insufficiency associated with nephrocalcinosis"
Nephrocalcinosis in an HDR patient with renal insufficiency.
Stage 5 chronic kidney disease OCCASIONAL HP:0003774 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is End-stage kidney disease, annotated with Stage 5 chronic kidney disease (HP:0003774). HP:0003774 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:27387476 SUPPORT REVIEW SYNTHESIS Human Clinical
"Overall, 10% of patients had reached ESRD."
Pooled frequency of ESRD across reported patients.
Female genital tract anomaly FREQUENT Abnormality of the female genitalia HP:0010460 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Female genital tract anomaly, annotated with Abnormality of the female genitalia (HP:0010460). HP:0010460 is a phenotype from the Human Phenotype Ontology.
Coarse binding: variable spectrum
Show evidence (3 references)
PMID:42595857 SUPPORT Human Clinical
"Among the extrarenal manifestations, female genital tract anomalies were present in 37.5% of female patients (3/8)"
Frequency of female genital tract anomalies among female GATA3 variant carriers in the cohort (FREQUENT band, females only). The 3/8 includes one carrier of a variant of uncertain significance; excluding her gives 2/7 (29%), just below the 30% FREQUENT threshold, so the band is approximate.
PMID:42595857 SUPPORT Human Clinical
"Congenital anomalies of the female genital tract were observed in several patients, consistent with previous studies"
The authors place their finding alongside earlier reports.
PMID:38940299 SUPPORT Human Clinical
"Some conditions such as hearing loss are almost always present, while others described as rare initially, do not seem to be so rare after all (genital malformations and basal ganglia calcifications)."
Independent cohort and review reporting genital malformations as a recurrent HDR feature.
Bicornuate uterus HP:0000813 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Bicornuate uterus (HP:0000813). HP:0000813 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:42595857 SUPPORT Human Clinical
"Decreased kidney func- tion Bicornuate uterus"
Table 1 row for patient SC1125m, listing decreased kidney function and bicornuate uterus.
Metabolism 3
Hypocalcemia VERY_FREQUENT HP:0002901 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Hypocalcemia (HP:0002901). HP:0002901 is a phenotype from the Human Phenotype Ontology.
Sequelae: Hypocalcemic seizures Tetany
Show evidence (1 reference)
PMID:37561279 SUPPORT Human Clinical
"The proband of family 1, a 17-year-old boy, was referred for severe hypocalcemia (5.9 mg/dL) incidentally detected at routine blood tests."
Severe hypocalcemia discovered incidentally in an HDR proband.
Hyperphosphatemia HP:0002905 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Hyperphosphatemia (HP:0002905). HP:0002905 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:31660939 SUPPORT Human Clinical
"Biochemical investigations showed persistent low serum corrected calcium levels with hyperphosphataemia, hypomagnesaemia, low parathyroid hormone levels, hypercalciuria, and low total 25-hydroxy vitamin D levels."
Hyperphosphatemia as part of the hypoparathyroid biochemical profile.
Hypomagnesemia HP:0002917 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Hypomagnesemia (HP:0002917). HP:0002917 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:31660939 SUPPORT Human Clinical
"On screening, his mother was also found to have asymptomatic hypocalcaemia, hypomagnesaemia, hyperphosphataemia, hypercalciuria and low total 25-hydroxy vitamin D levels."
Hypomagnesemia in an affected mother, alongside her son's identical profile.
Musculoskeletal 2
Tetany HP:0001281 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Carpopedal spasm, annotated with Tetany (HP:0001281). HP:0001281 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:31660939 SUPPORT Human Clinical
"A 13-year-old boy with an acute febrile illness, hypocalcaemia and bilateral carpopedal spasm was referred for evaluation."
Carpopedal spasm (tetany) with hypocalcemia in an HDR patient.
Basal ganglia calcification HP:0002135 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Basal ganglia calcification (HP:0002135). HP:0002135 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:38940299 SUPPORT Human Clinical
"Some conditions such as hearing loss are almost always present, while others described as rare initially, do not seem to be so rare after all (genital malformations and basal ganglia calcifications)."
Cohort plus systematic review reporting basal ganglia calcification as a not-rare feature.
Nervous System 1
Hypocalcemic seizures HP:0002199 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Hypocalcemic seizures (HP:0002199). HP:0002199 is a phenotype from the Human Phenotype Ontology.
Show evidence (2 references)
PMID:27387476 SUPPORT Human Clinical
"Hypoparathyroidism was present in six patients (with hypocalcaemia and inaugural seizures in two out of six)."
Seizures as the presenting manifestation of hypocalcemia in two of six hypoparathyroid patients.
PMID:37561279 SUPPORT Human Clinical
"had severe symptomatic hypocalcemia complicated by epileptic seizure at the age of 14 years"
A second report of a hypocalcemic seizure as presenting event.
🧬

Genetic Associations

1
GATA3 (Heterozygous loss-of-function variants or whole-gene deletion)
Gene: GATA3 hgnc:4172 HUGO Gene Nomenclature Committee (hgnc) Relation: this disease-associated gene is this gene This disease-associated gene is GATA3 (hgnc:4172). hgnc:4172 is a gene from the HUGO Gene Nomenclature Committee. relationship_type: CAUSATIVE variant_origin: GERMLINE
Autosomal Dominant
Show evidence (5 references)
PMID:10935639 SUPPORT Human Clinical
"We have performed deletion-mapping studies in two HDR patients, and here we define a critical 200-kilobase region which contains the GATA3 gene."
Deletion mapping to GATA3, the first line of evidence for the gene.
PMID:32442337 SUPPORT REVIEW SYNTHESIS Human Clinical
"Missense mutations were found to cluster in the regions encoding the two GATA3 zinc-finger domains."
Location of missense variants, stated in the notes.
PMID:32442337 SUPPORT REVIEW SYNTHESIS Human Clinical
"However, patients with whole-gene deletions and protein-truncating mutations were diagnosed earlier than patients with missense mutations."
The genotype-phenotype observation stated in the notes.
+ 2 more references
💊

Medical Actions

4
Calcium and Active Vitamin D Supplementation
Action: PharmacotherapyNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is Pharmacotherapy (NCIT:C15986). NCIT:C15986 is a clinical intervention from the NCI Thesaurus. NCIT:C15986
Agent: calcium carbonate CHEBI:3311 Chemical Entities of Biological Interest (CHEBI) Relation: this treatment uses this therapeutic agent This treatment uses calcium carbonate (CHEBI:3311). CHEBI:3311 is a therapeutic agent from Chemical Entities of Biological Interest. calcitriol CHEBI:17823 Chemical Entities of Biological Interest (CHEBI) Relation: this treatment uses this therapeutic agent This treatment uses calcitriol (CHEBI:17823). CHEBI:17823 is a therapeutic agent from Chemical Entities of Biological Interest.
Platform: Small molecule
Hypocalcemia due to hypoparathyroidism is treated as in other forms of hypoparathyroidism, with oral calcium and an active vitamin D analogue such as calcitriol, aiming for low-normal serum calcium to limit hypercalciuria and nephrocalcinosis, a particular concern when the kidneys are already abnormal.
Mechanism Target:
Hypocalcemia — Replaces calcium and bypasses the lost PTH-dependent activation of vitamin D.
Show evidence (1 reference)
PMID:37908274 SUPPORT Human Clinical
"Hypocalcemia was responsive to calcium carbonate and calcitriol treatment."
Case report of response of HDR-related hypocalcemia to calcium carbonate and calcitriol.
Parathyroid Hormone Replacement (Palopegteriparatide)
Action: PharmacotherapyNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is Pharmacotherapy (NCIT:C15986). NCIT:C15986 is a clinical intervention from the NCI Thesaurus. NCIT:C15986
Agent: palopegteriparatide CHEBI:759036 Chemical Entities of Biological Interest (CHEBI) Relation: this treatment uses this therapeutic agent This treatment uses palopegteriparatide (CHEBI:759036). CHEBI:759036 is a therapeutic agent from Chemical Entities of Biological Interest.
Platform: Peptide
Conventional calcium and active vitamin D does not replace the renal and skeletal actions of PTH and carries a risk of hypercalciuria, nephrocalcinosis and stones. Palopegteriparatide, a once-daily prodrug of PTH(1-34), is approved for chronic hypoparathyroidism as a replacement therapy and in the phase 3 PaTHway trial normalized urinary calcium and was associated with improved eGFR. The evidence is from adults with chronic hypoparathyroidism of mixed causes, not specifically HDR; it is relevant here because HDR patients often have structurally abnormal kidneys.
Mechanism Target:
Deficient Parathyroid Hormone Secretion — Replaces the missing hormone rather than compensating for its effects.
Show evidence (3 references)
PMID:28857066 SUPPORT REVIEW SYNTHESIS Other
"Conventional treatment includes activated vitamin D and/or calcium supplements, but this treatment does not fully replace the functions of PTH and can lead to short-term problems (such as hypocalcaemia, hypercalcaemia and increased urinary calcium excretion) and long-term complications (which..."
The limitation of conventional therapy that motivates PTH replacement.
PMID:42166177 SUPPORT Human Clinical
"Palopegteriparatide treatment normalized mean (SD) 24-h urine calcium within 26 wk and maintained levels below 250 mg/d through Week 104"
Trial evidence in chronic hypoparathyroidism of any cause (not HDR specifically) that PTH replacement controls hypercalciuria.
PMID:39987371 SUPPORT REVIEW SYNTHESIS Other
"Recently, the Food & Drug Administration and the European Medicines Agency approved palopegteriparatide as the first true replacement therapy for hypoPT management."
Regulatory approval status for hypoparathyroidism in general.
Hearing Rehabilitation (Hearing Aids or Cochlear Implantation)
Action: hearing device fitting and auditory rehabilitationNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is hearing device fitting and auditory rehabilitation, annotated with Rehabilitation (NCIT:C15315), qualified as medical device hearing aid. NCIT:C15315 is a clinical intervention from the NCI Thesaurus. Ontology label: Rehabilitation NCIT:C15315
Platform: Device
Hearing should be assessed as early as possible. Management follows that of other sensorineural hearing loss: hearing aids for mild-to-moderate loss and cochlear implantation for severe-to-profound loss.
Mechanism Target:
Bilateral sensorineural hearing impairment
Show evidence (2 references)
PMID:38940299 SUPPORT Human Clinical
"As mentioned in the literature, hearing function should always be assessed as early as possible"
Recommendation for early hearing assessment, the entry point to hearing rehabilitation.
PMID:29073906 SUPPORT Human Clinical
"A 14-month-old boy, with sensorineural hearing loss in both ears, showed typical radiological features of X-linked stapes gusher on preoperative temporal bone computed tomography (CT) for cochlear implantations."
An HDR infant evaluated for cochlear implantation; documents the use of implantation in this disease, not its outcome.
Kidney Transplantation
Action: kidney transplantationNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is kidney transplantation (NCIT:C15265). NCIT:C15265 is a clinical intervention from the NCI Thesaurus. Ontology label: Kidney Transplantation NCIT:C15265
Platform: Surgery
For patients reaching end-stage kidney disease, kidney transplantation has been performed with long-term success, including a living related graft functioning for 26 years.
Mechanism Target:
Stage 5 chronic kidney disease
Show evidence (2 references)
PMID:41064049 SUPPORT Human Clinical
"He had a living donor kidney transplant at age 47 that was well tolerated until age 73, and he is now listed for a repeat transplant."
Long-term graft survival after transplantation in HDR.
PMID:41064049 SUPPORT Human Clinical
"Current limited evidence suggests kidney transplantation should be readily offered to individuals with end-stage renal disease due to HDR syndrome."
Authors' recommendation, based on limited case evidence.
🔬

Diagnosis

1
Clinical and Molecular Diagnosis of HDR Syndrome
HDR should be considered in any patient with two of the three components, and in particular in hypoparathyroidism with deafness whether or not renal disease is present, and in chronic kidney disease with sensorineural deafness. Apparently idiopathic hypoparathyroidism warrants evaluation of hearing and kidneys. The diagnosis is confirmed by a heterozygous pathogenic GATA3 variant; copy-number analysis is required because about 15% of variants are whole-gene deletions. Relatives should be screened for parathyroid, auditory and renal involvement given the variable expressivity.
Show evidence (4 references)
PMID:27387476 SUPPORT Human Clinical
"Diagnosis of HDR should be considered in any patient with hypoparathyroidism and deafness, whether associated with renal abnormalities or not. HDR diagnosis is established through identification of a mutation in the GATA-3 gene."
Diagnostic recommendation and confirmation by GATA3 testing.
PMID:42595857 SUPPORT Human Clinical
"In patients with CKD and sensorineural deafness, HDR syndrome should be considered, and comprehensive genetic testing, including copy number analysis, is essential for accurate diagnosis."
Supports testing in CKD with deafness and the need for copy-number analysis.
PMID:37561279 SUPPORT Human Clinical
"HDR syndrome is a rare cause of hypoparathyroidism and must be excluded in all patients with apparently idiopathic hypoparathyroidism."
Supports evaluating idiopathic hypoparathyroidism for HDR.
+ 1 more reference
📊

Prevalence

1
Worldwide
Cases In Literature Rare
No population prevalence estimate exists. By 2020, GATA3 variants had been reported in 124 families (177 patients). In a Japanese cohort of 1254 families tested for chronic kidney disease, 7 families (10 patients) had pathogenic or likely pathogenic GATA3 variants.
Show evidence (2 references)
PMID:32442337 SUPPORT REVIEW SYNTHESIS Human Clinical
"In the last 20 years, since the identification of the genetic cause of the HDR syndrome, GATA3 mutations have been reported in 124 families (177 patients)."
Count of reported families and patients.
PMID:42595857 SUPPORT Human Clinical
"Among 1254 families with CKD, pathogenic or likely pathogenic GATA3 variants were identified in 10 patients (seven families)."
Diagnostic yield of GATA3 in a CKD genetic-testing cohort.
🔀

Differential Diagnoses

3

Conditions with similar clinical presentations that must be differentiated from Hypoparathyroidism-Deafness-Renal Disease Syndrome:

22q11.2 deletion syndrome MONDO:0018923
Overlapping Features Shares hypoparathyroidism and can include renal anomalies and hearing loss; distinguished by conotruncal heart defects, immunodeficiency and palatal anomalies. Terminal 10p deletions give an overlapping DiGeorge-like picture.
Show evidence (1 reference)
PMID:10935639 SUPPORT Human Clinical
"Terminal deletions of chromosome 10p result in a DiGeorge-like phenotype that includes hypoparathyroidism, heart defects, immune deficiency, deafness and renal malformations."
Documents the phenotypic overlap between 10p deletions (including GATA3) and DiGeorge syndrome.
Alport syndrome MONDO:0018965
Overlapping Features Combines sensorineural hearing loss with progressive kidney disease and can be misdiagnosed for HDR in adults; lacks hypoparathyroidism and congenital renal malformation, and has ocular findings and type IV collagen variants.
Show evidence (1 reference)
PMID:41064049 SUPPORT Human Clinical
"This individual previously had a clinical diagnosis of Alport syndrome, but the presence of congenital symptoms in other family members suggested an alternative diagnosis."
A documented misdiagnosis of HDR as Alport syndrome.
Branchiootorenal syndrome Not Yet Curated MONDO:0007236
Overlapping Features Combines hearing loss with renal dysplasia or hypoplasia, but hearing loss is often conductive or mixed, branchial and ear malformations are present, and parathyroid function is normal.
Show evidence (1 reference)
PMID:42595857 SUPPORT Human Clinical
"In such cases, the major differential diagnoses include Alport syndrome, branchio-oto-renal syndrome"
Names branchio-oto-renal syndrome as a major differential for the deafness plus renal (DR) presentation of HDR. In the same cohort's Table 1, several GATA3 variant carriers had a prior clinical diagnosis of BOR.
🐁

Animal Models

1
Gata3 heterozygous knockout mouse
The heterozygous null mouse is the genetic equivalent of HDR. Under a low-calcium, low-vitamin D diet it shows smaller parathyroids with low PTH and calcium; it has progressive cochlear hair cell degeneration with about 30 dB hearing loss; and it has a mesangial precursor deficit with glomerular abnormalities. Homozygous nulls die in utero and lack parathyroid-thymus primordia and kidneys.
Species
Mouse
Genotype
Gata3 +/-
Publication
PMID:20484821
Pathograph links
Parathyroid Gland Hypoplasia recapitulates fidelity: moderate observes: tissue
Limitations: The parathyroid defect is exposed by dietary calcium and vitamin D restriction rather than being overt on a normal diet.
Show evidence (1 reference)
PMID:20484821 SUPPORT Model Organism
"Compared with their wild-type littermates, Gata3+/- mice had lower plasma concentrations of calcium and parathyroid hormone (PTH) and smaller parathyroid glands with a reduced Ki-67 proliferation rate."
Heterozygous mice reproduce the hypoplastic parathyroid and low PTH.
Cochlear Outer Hair Cell Degeneration recapitulates fidelity: high observes: cellular
Show evidence (1 reference)
PMID:15207274 SUPPORT Model Organism
"Auditory brainstem response (ABR) thresholds of alert heterozygous Gata3 mice, analyzed from 1 to 19 months of age, showed a hearing loss of 30 dB compared to wild-type littermates."
Hearing loss in heterozygous mice, with cochlear origin.
Mesangial Cell Precursor Deficiency recapitulates fidelity: moderate observes: cellular
Show evidence (1 reference)
PMID:31405951 SUPPORT Model Organism
"In mice, we uncover that GATA3 is essential for normal glomerular development, and mice with haploinsufficiency of Gata3 have too few MC precursors and glomerular abnormalities."
Heterozygous mice show the mesangial precursor deficit.
{ }

Source YAML

click to show 
name: Hypoparathyroidism-Deafness-Renal Disease Syndrome
creation_date: "2026-09-23T19:10:07Z"
category: Mendelian
description: >-
  Hypoparathyroidism-deafness-renal disease (HDR) syndrome, also called Barakat
  syndrome, is an autosomal dominant developmental disorder caused by
  heterozygous loss-of-function variants or whole-gene deletions of GATA3, a
  dual zinc-finger transcription factor required for development of the
  parathyroid glands, the cochlea and the kidney. It is defined by the triad of
  hypoparathyroidism with hypocalcemia, bilateral sensorineural hearing loss and
  renal disease, which ranges from dysplasia, hypoplasia, agenesis, cysts and
  vesicoureteral reflux to glomerular disease with proteinuria and progression
  to end-stage kidney disease in a minority. Penetrance and expressivity of
  each component are variable, even within one family, and the penetrance of
  each defect increases with age. Hearing loss is the most constant feature;
  only about two thirds of reported patients show the complete triad.
synonyms:
- Barakat syndrome
- HDR syndrome
- hypoparathyroidism, sensorineural deafness, and renal dysplasia syndrome
- hypoparathyroidism, deafness, and renal anomalies syndrome
- hypoparathyroidism, sensorineural deafness, and renal disease
- nephrosis, nerve deafness, and hypoparathyroidism
disease_term:
  preferred_term: hypoparathyroidism-deafness-renal disease syndrome
  term:
    id: MONDO:0007797
    label: hypoparathyroidism-deafness-renal disease syndrome
inheritance:
- name: Autosomal Dominant
  inheritance_term:
    preferred_term: Autosomal dominant inheritance
    term:
      id: HP:0000006
      label: Autosomal dominant inheritance
  description: >-
    HDR syndrome is inherited as an autosomal dominant trait with variable
    penetrance of each of its components. Both familial transmission and de
    novo variants are reported.
  evidence:
  - reference: PMID:38940299
    reference_title: "HDR syndrome: Large cohort and systematic review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      An autosomal dominant disease caused by heterozygous pathogenic GATA3
      variants, the penetrance of each associated condition is variable.
    explanation: >-
      States the dominant mode of inheritance and the variable penetrance of
      each component in a 28-patient cohort combined with a literature review.
  - reference: PMID:32442337
    reference_title: "Hypoparathyroidism, deafness, and renal dysplasia syndrome: 20 Years after the identification of the first GATA3 mutations."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: REVIEW_SYNTHESIS
    snippet: >-
      The hypoparathyroidism, deafness, and renal dysplasia (HDR) syndrome is an
      autosomal dominant disorder caused by heterozygous mutations of the GATA3
      gene.
    explanation: >-
      Review of all reported families restating the autosomal dominant
      inheritance of heterozygous GATA3 variants.
pathophysiology:
- name: GATA3 Haploinsufficiency
  biological_scale: MOLECULAR
  description: >-
    Heterozygous GATA3 variants (frameshift, nonsense, splice-site, missense
    and whole-gene deletions) halve the dose of functional GATA3. Over 90% of
    characterized variants abolish DNA binding by removing or disrupting the
    C-terminal zinc finger; missense variants cluster in the two zinc-finger
    domains and either abolish DNA binding, reduce binding affinity, or, for
    N-terminal finger variants, disrupt interaction with the cofactor FOG2.
    Whole-gene deletions produce the same syndrome, which is the primary
    argument for haploinsufficiency as the mechanism.
  genetic_context:
    gene:
      preferred_term: GATA3
      term:
        id: hgnc:4172
        label: GATA3
    variant_origin: GERMLINE
    zygosity: HETEROZYGOUS
    functional_impact_category: LOSS_OF_FUNCTION
  molecular_functions:
  - preferred_term: GATA3 sequence-specific DNA-binding transcription factor activity
    modifier: DECREASED
    term:
      id: GO:0003700
      label: DNA-binding transcription factor activity
  downstream:
  - target: Reduced GCM2 Expression in Parathyroid Progenitors
    causal_link_type: DIRECT
  - target: Reduced PTH Gene Transactivation
    causal_link_type: DIRECT
  - target: Cochlear Outer Hair Cell Degeneration
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
  - target: Dysregulated Nephric Duct and Ureteric Bud Development
    causal_link_type: DIRECT
  - target: Mesangial Cell Precursor Deficiency
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
  evidence:
  - reference: PMID:10935639
    reference_title: "GATA3 haplo-insufficiency causes human HDR syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Investigation for GATA3 mutations in three other HDR probands identified
      one nonsense mutation and two intragenic deletions that predicted a loss
      of function, as confirmed by absence of DNA binding by the mutant GATA3
      protein.
    explanation: >-
      The gene-discovery study: deletion mapping plus loss-of-function point
      variants establish GATA3 haploinsufficiency as the cause of HDR.
  - reference: PMID:17210674
    reference_title: "Functional characterization of GATA3 mutations causing the hypoparathyroidism-deafness-renal (HDR) dysplasia syndrome: insight into mechanisms of DNA binding by the GATA3 transcription factor."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      Electrophoretic mobility shift assays (EMSAs) revealed three classes of
      GATA3 mutations: those that lead to a loss of DNA binding which represent
      over 90% of all mutations, and involved a loss of the carboxy-terminal
      zinc finger
    explanation: >-
      Functional assays showing that the large majority of HDR alleles abolish
      DNA binding, the molecular basis of the dosage loss.
  - reference: PMID:14985365
    reference_title: "Characterization of GATA3 mutations in the hypoparathyroidism, deafness, and renal dysplasia (HDR) syndrome."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      Mutations involving GATA3 ZnF2 or adjacent basic amino acids resulted in a
      loss of DNA binding, but those of ZnF1 either lead to a loss of
      interaction with specific FOG2 ZnFs or altered DNA-binding affinity.
    explanation: >-
      Distinguishes the two functional classes of zinc-finger variants
      summarized in the node description.
  - reference: PMID:32442337
    reference_title: "Hypoparathyroidism, deafness, and renal dysplasia syndrome: 20 Years after the identification of the first GATA3 mutations."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: REVIEW_SYNTHESIS
    snippet: >-
      Reported mutations consist of 40% frameshift deletions or insertions, 23%
      missense mutations, 14% nonsense mutations, 6% splice-site mutations, 1%
      in-frame deletions or insertions, 15% whole-gene deletions, and 1%
      whole-gene duplication.
    explanation: >-
      Allelic spectrum across 124 reported families; the prominence of
      truncating variants and whole-gene deletions supports dosage loss.
- name: Reduced GCM2 Expression in Parathyroid Progenitors
  biological_scale: MOLECULAR
  description: >-
    GATA3 binds a double-GATA motif in the promoter of GCM2 (GCMB), the
    parathyroid-specific transcription factor, and is required for its
    expression in the third pharyngeal pouch. Halving GATA3 dose reduces the
    number of GCM2-expressing parathyroid progenitors.
  notes: >-
    The cell type is bound to the mature CL:0000446 chief cell of parathyroid
    gland because CL has no parathyroid progenitor term. An OLS search of CL
    for "parathyroid progenitor" returned no results, and a search for
    "parathyroid" returned only mature parathyroid cell types (chief, clear,
    dark, light, active and inactive chief cells, oxyphil, transitional,
    glandular and epithelial cells of the parathyroid gland).
  cell_types:
  - preferred_term: parathyroid chief cell progenitor
    term:
      id: CL:0000446
      label: chief cell of parathyroid gland
  biological_processes:
  - preferred_term: parathyroid gland development
    modifier: DECREASED
    term:
      id: GO:0060017
      label: parathyroid gland development
  downstream:
  - target: Parathyroid Gland Hypoplasia
    causal_link_type: DIRECT
  evidence:
  - reference: PMID:20484821
    reference_title: "Gata3-deficient mice develop parathyroid abnormalities due to dysregulation of the parathyroid-specific transcription factor Gcm2."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      Electrophoretic mobility shift, luciferase reporter, and chromatin
      immunoprecipitation assays showed that GATA3 binds specifically to a
      functional double-GATA motif within the GCMB promoter.
    explanation: >-
      Direct binding of GATA3 to the GCMB promoter places GCM2 downstream of
      GATA3.
  - reference: PMID:20484821
    reference_title: "Gata3-deficient mice develop parathyroid abnormalities due to dysregulation of the parathyroid-specific transcription factor Gcm2."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      At E11.5, Gata3+/- embryos had smaller parathyroid-thymus primordia with
      fewer cells expressing the parathyroid-specific gene glial cells missing 2
      (Gcm2), the homolog of human GCMB.
    explanation: >-
      Heterozygous mouse embryos, the genetic equivalent of HDR, have fewer
      Gcm2-expressing parathyroid progenitors.
- name: Parathyroid Gland Hypoplasia
  biological_scale: TISSUE
  description: >-
    Reduced specification and survival of parathyroid progenitors leaves
    smaller parathyroid glands with reduced proliferative capacity, which cannot
    mount an adequate response to hypocalcemic challenge.
  locations:
  - preferred_term: parathyroid gland
    term:
      id: UBERON:0001132
      label: parathyroid gland
  downstream:
  - target: Deficient Parathyroid Hormone Secretion
    causal_link_type: DIRECT
  evidence:
  - reference: PMID:20484821
    reference_title: "Gata3-deficient mice develop parathyroid abnormalities due to dysregulation of the parathyroid-specific transcription factor Gcm2."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      Compared with their wild-type littermates, Gata3+/- mice had lower plasma
      concentrations of calcium and parathyroid hormone (PTH) and smaller
      parathyroid glands with a reduced Ki-67 proliferation rate.
    explanation: >-
      Gata3 heterozygous mice have hypoplastic, hypoproliferative parathyroids
      together with low PTH and calcium.
- name: Reduced PTH Gene Transactivation
  biological_scale: MOLECULAR
  description: >-
    In addition to its developmental role, GATA3 cooperates with GCM2, MAFB and
    SP1 to activate the parathyroid hormone gene promoter. HDR-associated GATA3
    mutants fail to activate the PTH promoter, so PTH output per parathyroid
    cell may also be reduced.
  biological_processes:
  - preferred_term: GATA3-dependent activation of PTH transcription
    modifier: DECREASED
    term:
      id: GO:0045944
      label: positive regulation of transcription by RNA polymerase II
  downstream:
  - target: Deficient Parathyroid Hormone Secretion
    causal_link_type: DIRECT
  evidence:
  - reference: PMID:25917456
    reference_title: "Gata3 cooperates with Gcm2 and MafB to activate parathyroid hormone gene expression by interacting with SP1."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      Gata3 interacted with Gcm2 and MafB, two known transcriptional regulators
      of parathyroid development, and synergistically stimulated the PTH
      promoter.
    explanation: >-
      Places GATA3 directly on the PTH promoter as a co-activator.
  - reference: PMID:25917456
    reference_title: "Gata3 cooperates with Gcm2 and MafB to activate parathyroid hormone gene expression by interacting with SP1."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      HDR syndrome-associated Gata3 mutants were defective in activating the PTH
      promoter.
    explanation: >-
      Disease alleles lose this transactivation function.
- name: Deficient Parathyroid Hormone Secretion
  biological_scale: ORGANISM
  description: >-
    Circulating PTH is low or inappropriately normal for the serum calcium.
    Loss of PTH action reduces renal calcium reabsorption, bone resorption and
    renal phosphate excretion, producing hypocalcemia with hyperphosphatemia
    and, in treated patients, hypercalciuria.
  biological_processes:
  - preferred_term: parathyroid hormone secretion
    modifier: DECREASED
    term:
      id: GO:0035898
      label: parathyroid hormone secretion
  downstream:
  - target: Hypoparathyroidism
    causal_link_type: DIRECT
  - target: Decreased circulating parathyroid hormone level
    causal_link_type: DIRECT
  - target: Hypocalcemia
    causal_link_type: DIRECT
  - target: Hyperphosphatemia
    causal_link_type: DIRECT
  - target: Hypomagnesemia
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
  - target: Hypercalciuria
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
  - target: Basal ganglia calcification
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
  evidence:
  - reference: PMID:31660939
    reference_title: "Hypoparathyroidism, Sensorineural deafness and renal disease (Barakat syndrome) caused by a reduced gene dosage in GATA3: a case report and review of literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Biochemical investigations showed persistent low serum corrected calcium
      levels with hyperphosphataemia, hypomagnesaemia, low parathyroid hormone
      levels, hypercalciuria, and low total 25-hydroxy vitamin D levels.
    explanation: >-
      The biochemical profile of PTH deficiency in a patient with a GATA3
      whole-gene deletion.
- name: Cochlear Outer Hair Cell Degeneration
  biological_scale: CELLULAR
  description: >-
    The hearing loss of HDR is peripheral (cochlear) rather than central. In
    Gata3 heterozygous mice, degeneration starts in the outer hair cells at the
    cochlear apex and progresses to involve all hair cells and supporting cells;
    otoacoustic emissions deteriorate rapidly and outer hair cells accumulate
    vacuoles. Psychophysical testing in HDR patients shows the signature of
    outer hair cell loss. Complete loss of Gata3 in the developing inner ear
    additionally abolishes prosensory specification and depletes spiral
    ganglion neurons, showing that the gene is required at several steps of
    cochlear development.
  cell_types:
  - 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: cochlea development
    modifier: DECREASED
    term:
      id: GO:0090102
      label: cochlea development
  downstream:
  - target: Bilateral sensorineural hearing impairment
    causal_link_type: DIRECT
  evidence:
  - reference: PMID:15207274
    reference_title: "Hearing loss following Gata3 haploinsufficiency is caused by cochlear disorder."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      cochleae of heterozygous Gata3 mice showed significant progressive
      morphological degeneration starting with the outer hair cells (OHCs) at
      the apex and ultimately affecting all hair cells and supporting cells in
      the entire cochlea
    explanation: >-
      Localizes the auditory lesion of Gata3 haploinsufficiency to cochlear
      hair cells, beginning with the outer hair cells.
  - reference: PMID:15994092
    reference_title: "GATA3 haploinsufficiency causes a rapid deterioration of distortion product otoacoustic emissions (DPOAEs) in mice."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      Together, these findings indicate that outer hair cell malfunctioning
      plays a major role in the hearing loss in HDR-syndrome.
    explanation: >-
      Functional (DPOAE) and ultrastructural evidence for outer hair cell
      failure in the heterozygous mouse.
  - reference: PMID:24434941
    reference_title: "Audiometric characteristics of a dutch family with a new mutation in GATA3 causing HDR syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Overall, the results of the psychophysical measurements indicated
      characteristics of outer hair cell loss.
    explanation: >-
      Human psychophysical data consistent with the outer hair cell mechanism
      seen in mice.
  - reference: PMID:31069810
    reference_title: "Gata3 is required for the functional maturation of inner hair cells and their innervation in the mouse cochlea."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      Here, we find that in heterozygous gata3 null mice (gata3+/- ) outer hair
      cells (OHCs) differentiate normally but their numbers are significantly
      lower.
    explanation: >-
      Confirms outer hair cell loss in the heterozygous state, the genotype of
      HDR patients; the same study shows immature inner hair cells as a second
      contributor.
  - reference: PMID:23666531
    reference_title: "GATA3 controls the specification of prosensory domain and neuronal survival in the mouse cochlea."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      Loss of Gata3 function leads to the failure in the specification of
      prosensory domain and subsequently, to increased cell death in the
      cochlear duct.
    explanation: >-
      Complete inner-ear loss of Gata3 shows its requirement in cochlear
      development; this is a stronger lesion than the human heterozygous state.
- name: Dysregulated Nephric Duct and Ureteric Bud Development
  biological_scale: CELLULAR
  description: >-
    GATA3 is expressed in the nephric (Wolffian) duct downstream of PAX2/PAX8
    and beta-catenin and upstream of RET. Its loss causes premature nephric duct
    differentiation, loss of RET expression and ectopic ureteric budding,
    producing a spectrum of congenital anomalies of the kidney and urinary tract
    (renal adysplasia, duplex systems, hydroureter) and of the genital tract
    derived from the same primordia. This is the proposed basis for the
    dysplastic renal and genital malformations of HDR, although the mouse
    evidence comes from homozygous or conditional loss rather than
    heterozygosity.
  cell_types:
  - preferred_term: ureteric bud cell
    term:
      id: CL:4030066
      label: ureteric bud cell
  biological_processes:
  - preferred_term: mesonephric duct development
    modifier: ABNORMAL
    term:
      id: GO:0072177
      label: mesonephric duct development
  - preferred_term: ureteric bud development
    modifier: ABNORMAL
    term:
      id: GO:0001657
      label: ureteric bud development
  downstream:
  - target: Renal dysplasia
    causal_link_type: DIRECT
  - target: Renal hypoplasia
    causal_link_type: DIRECT
  - target: Multicystic kidney dysplasia
    causal_link_type: DIRECT
  - target: Renal cyst
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
  - target: Vesicoureteral reflux
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
  - target: Female genital tract anomaly
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
  - target: Bicornuate uterus
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
  - target: Unilateral renal agenesis
    causal_link_type: DIRECT
  - target: Hydronephrosis
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
  - target: Glomerular Injury and Progressive Nephron Loss
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: >-
      Congenitally dysplastic or hypoplastic kidneys start with a reduced
      nephron complement, one route to later loss of kidney function.
  evidence:
  - reference: PMID:19112489
    reference_title: "Gata3 acts downstream of beta-catenin signaling to prevent ectopic metanephric kidney induction."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      Here, we show that the nephric duct-specific inactivation of the
      transcription factor gene Gata3 leads to massive ectopic ureter budding.
      This results in a spectrum of urogenital malformations including kidney
      adysplasia, duplex systems, and hydroureter, as well as vas deferens
      hyperplasia and uterine agenesis.
    explanation: >-
      Links loss of Gata3 in the nephric duct to renal adysplasia and genital
      tract malformations resembling human CAKUT.
  - reference: PMID:19112489
    reference_title: "Gata3 acts downstream of beta-catenin signaling to prevent ectopic metanephric kidney induction."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      We show that Gata3 inactivation causes premature nephric duct cell
      differentiation and loss of Ret receptor gene expression.
    explanation: >-
      Identifies the cellular defect: premature differentiation and loss of RET.
  - reference: PMID:16319112
    reference_title: "Pax 2/8-regulated Gata 3 expression is necessary for morphogenesis and guidance of the nephric duct in the developing kidney."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      At the molecular level, the nephric duct of Gata3(-/-) embryos is
      characterized by the loss of Ret expression and signaling
    explanation: >-
      Independent confirmation that Gata3 is required for RET expression in the
      nephric duct.
- name: Mesangial Cell Precursor Deficiency
  biological_scale: CELLULAR
  description: >-
    GATA3 is expressed in FOXD1-lineage stromal progenitors that give rise to
    glomerular mesangial cells and remains expressed in adult mesangial cells.
    Gata3 heterozygous mice have too few mesangial precursors and glomerular
    abnormalities, which offers a mechanism for the glomerular disease
    (mesangioproliferative glomerulonephritis, proteinuria, focal segmental
    glomerulosclerosis) seen in some HDR patients.
  cell_types:
  - preferred_term: glomerular mesangial cell
    term:
      id: CL:1000742
      label: glomerular mesangial cell
  biological_processes:
  - preferred_term: glomerulus development
    modifier: DECREASED
    term:
      id: GO:0032835
      label: glomerulus development
  downstream:
  - target: Glomerular Injury and Progressive Nephron Loss
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
  evidence:
  - reference: PMID:31405951
    reference_title: "A Novel Role for GATA3 in Mesangial Cells in Glomerular Development and Injury."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      In mice, we uncover that GATA3 is essential for normal glomerular
      development, and mice with haploinsufficiency of Gata3 have too few MC
      precursors and glomerular abnormalities.
    explanation: >-
      Heterozygous Gata3 mice, the genetic equivalent of HDR, have a mesangial
      precursor deficit and glomerular abnormalities.
- name: Glomerular Injury and Progressive Nephron Loss
  biological_scale: TISSUE
  description: >-
    Dysplastic or hypoplastic kidneys and glomerular lesions lead in a subset
    of patients to proteinuria, sometimes in the nephrotic range, focal
    segmental glomerulosclerosis, and a progressive fall in kidney function.
    About one in ten reported patients reaches end-stage kidney disease, at ages
    from adolescence to late adulthood. The renal course is the main
    determinant of overall prognosis.
  locations:
  - preferred_term: kidney
    term:
      id: UBERON:0002113
      label: kidney
  downstream:
  - target: Nephrotic range proteinuria
    causal_link_type: DIRECT
  - target: Focal segmental glomerulosclerosis
    causal_link_type: DIRECT
  - target: Stage 5 chronic kidney disease
    causal_link_type: DIRECT
  evidence:
  - reference: PMID:27387476
    reference_title: "Clinical and mutational spectrum of hypoparathyroidism, deafness and renal dysplasia syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Three patients displayed nephrotic-range proteinuria and reached end-stage
      renal disease (ESRD) between the ages of 19 and 61 years, whilst lesions
      of focal and segmental glomerulosclerosis were histologically
      demonstrated in one of them.
    explanation: >-
      Documents the glomerular course: nephrotic-range proteinuria, FSGS and
      ESRD in the same patients.
  - reference: PMID:31405951
    reference_title: "A Novel Role for GATA3 in Mesangial Cells in Glomerular Development and Injury."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: BACKGROUND
    snippet: >-
      In humans, autosomal dominant GATA3 mutations can cause renal aplasia as
      part of the hypoparathyroidism, renal dysplasia, deafness (HDR) syndrome
      that includes mesangioproliferative GN.
    explanation: >-
      Background statement from the mouse study linking HDR to glomerular
      (mesangioproliferative) disease in patients.
phenotypes:
- category: Endocrine
  name: Hypoparathyroidism
  frequency: VERY_FREQUENT
  description: >-
    Present in about 87-95% of reported patients across literature reviews,
    though lower (45%) in patients ascertained through kidney disease clinics.
    Mean age at diagnosis is about 7.5 years, but it may be found incidentally
    in adulthood. It is usually the component that brings the patient to
    medical attention, through symptomatic hypocalcemia.
  phenotype_term:
    preferred_term: Hypoparathyroidism
    term:
      id: HP:0000829
      label: Hypoparathyroidism
  evidence:
  - reference: PMID:32442337
    reference_title: "Hypoparathyroidism, deafness, and renal dysplasia syndrome: 20 Years after the identification of the first GATA3 mutations."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: REVIEW_SYNTHESIS
    snippet: >-
      The most frequently observed abnormality was deafness (93%), followed by
      hypoparathyroidism (87%) and renal defects (61%).
    explanation: >-
      Frequency of hypoparathyroidism across 177 reported patients.
  - reference: PMID:27387476
    reference_title: "Clinical and mutational spectrum of hypoparathyroidism, deafness and renal dysplasia syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: REVIEW_SYNTHESIS
    snippet: >-
      Review of 115 previously reported cases of GATA-3 mutations showed
      hypoparathyroidism and deafness in 95% of patients, and renal
      abnormalities in only 60%.
    explanation: >-
      Independent literature review with a similar frequency estimate.
  - reference: PMID:42595857
    reference_title: "Clinical and genetic characteristics of hypoparathyroidism, deafness, and renal dysplasia syndrome in a chronic kidney disease cohort."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Regarding the classical triad, hypoparathyroidism, deafness, and renal
      anomalies were observed in 45, 100, and 90% of patients, respectively.
    explanation: >-
      Shows ascertainment dependence: in a kidney disease cohort
      hypoparathyroidism was present in under half of patients.
- category: Laboratory
  name: Decreased circulating parathyroid hormone level
  description: >-
    PTH is low, or inappropriately normal for the degree of hypocalcemia.
  phenotype_term:
    preferred_term: Decreased circulating parathyroid hormone level
    term:
      id: HP:0031817
      label: Decreased circulating parathyroid hormone level
  evidence:
  - reference: PMID:31660939
    reference_title: "Hypoparathyroidism, Sensorineural deafness and renal disease (Barakat syndrome) caused by a reduced gene dosage in GATA3: a case report and review of literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Biochemical investigations showed persistent low serum corrected calcium
      levels with hyperphosphataemia, hypomagnesaemia, low parathyroid hormone
      levels, hypercalciuria, and low total 25-hydroxy vitamin D levels.
    explanation: >-
      Low PTH documented in a patient with a GATA3 whole-gene deletion.
- category: Laboratory
  name: Hypocalcemia
  frequency: VERY_FREQUENT
  description: >-
    Hypocalcemia, symptomatic or found incidentally, follows from PTH
    deficiency and can be severe.
  phenotype_term:
    preferred_term: Hypocalcemia
    term:
      id: HP:0002901
      label: Hypocalcemia
  sequelae:
  - target: Hypocalcemic seizures
    causal_link_type: DIRECT
  - target: Tetany
    causal_link_type: DIRECT
  evidence:
  - reference: PMID:37561279
    reference_title: "Clinical and molecular characteristics of two Italian kindreds with hypoparathyroidism, deafness and renal dysplasia (HDR) syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The proband of family 1, a 17-year-old boy, was referred for severe
      hypocalcemia (5.9 mg/dL) incidentally detected at routine blood tests.
    explanation: >-
      Severe hypocalcemia discovered incidentally in an HDR proband.
- category: Laboratory
  name: Hyperphosphatemia
  description: >-
    Hyperphosphatemia accompanies hypocalcemia because PTH-driven renal
    phosphate excretion is lost.
  phenotype_term:
    preferred_term: Hyperphosphatemia
    term:
      id: HP:0002905
      label: Hyperphosphatemia
  evidence:
  - reference: PMID:31660939
    reference_title: "Hypoparathyroidism, Sensorineural deafness and renal disease (Barakat syndrome) caused by a reduced gene dosage in GATA3: a case report and review of literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Biochemical investigations showed persistent low serum corrected calcium
      levels with hyperphosphataemia, hypomagnesaemia, low parathyroid hormone
      levels, hypercalciuria, and low total 25-hydroxy vitamin D levels.
    explanation: >-
      Hyperphosphatemia as part of the hypoparathyroid biochemical profile.
- category: Laboratory
  name: Hypomagnesemia
  description: >-
    Hypomagnesemia has been reported alongside hypocalcemia in both a child and
    his mother carrying a GATA3 whole-gene deletion.
  phenotype_term:
    preferred_term: Hypomagnesemia
    term:
      id: HP:0002917
      label: Hypomagnesemia
  evidence:
  - reference: PMID:31660939
    reference_title: "Hypoparathyroidism, Sensorineural deafness and renal disease (Barakat syndrome) caused by a reduced gene dosage in GATA3: a case report and review of literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      On screening, his mother was also found to have asymptomatic
      hypocalcaemia, hypomagnesaemia, hyperphosphataemia, hypercalciuria and
      low total 25-hydroxy vitamin D levels.
    explanation: >-
      Hypomagnesemia in an affected mother, alongside her son's identical
      profile.
- category: Laboratory
  name: Hypercalciuria
  description: >-
    Without PTH, renal tubular calcium reabsorption falls, so urinary calcium
    is high relative to serum calcium; this is aggravated by calcium and
    active vitamin D treatment and is the reason treatment targets
    low-normal serum calcium.
  phenotype_term:
    preferred_term: Hypercalciuria
    term:
      id: HP:0002150
      label: Hypercalciuria
  sequelae:
  - target: Nephrocalcinosis
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
  evidence:
  - reference: PMID:31660939
    reference_title: "Hypoparathyroidism, Sensorineural deafness and renal disease (Barakat syndrome) caused by a reduced gene dosage in GATA3: a case report and review of literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      On screening, his mother was also found to have asymptomatic
      hypocalcaemia, hypomagnesaemia, hyperphosphataemia, hypercalciuria and
      low total 25-hydroxy vitamin D levels.
    explanation: >-
      Hypercalciuria documented in an untreated, newly identified affected
      relative.
- category: Neurological
  name: Hypocalcemic seizures
  description: >-
    Seizures due to hypocalcemia are a recognized presenting event (in one
    series, 2 of 6 patients with hypoparathyroidism presented this way), from
    infancy
    (sometimes provoked by fever) to adolescence.
  phenotype_term:
    preferred_term: Hypocalcemic seizures
    term:
      id: HP:0002199
      label: Hypocalcemic seizures
  evidence:
  - reference: PMID:27387476
    reference_title: "Clinical and mutational spectrum of hypoparathyroidism, deafness and renal dysplasia syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Hypoparathyroidism was present in six patients (with hypocalcaemia and
      inaugural seizures in two out of six).
    explanation: >-
      Seizures as the presenting manifestation of hypocalcemia in two of six
      hypoparathyroid patients.
  - reference: PMID:37561279
    reference_title: "Clinical and molecular characteristics of two Italian kindreds with hypoparathyroidism, deafness and renal dysplasia (HDR) syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      had severe symptomatic hypocalcemia complicated by epileptic seizure at
      the age of 14 years
    explanation: >-
      A second report of a hypocalcemic seizure as presenting event.
- category: Neurological
  name: Tetany
  description: >-
    Neuromuscular irritability from hypocalcemia, presenting as carpopedal
    spasm.
  phenotype_term:
    preferred_term: Carpopedal spasm
    term:
      id: HP:0001281
      label: Tetany
  evidence:
  - reference: PMID:31660939
    reference_title: "Hypoparathyroidism, Sensorineural deafness and renal disease (Barakat syndrome) caused by a reduced gene dosage in GATA3: a case report and review of literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      A 13-year-old boy with an acute febrile illness, hypocalcaemia and
      bilateral carpopedal spasm was referred for evaluation.
    explanation: >-
      Carpopedal spasm (tetany) with hypocalcemia in an HDR patient.
- category: Neurological
  name: Basal ganglia calcification
  description: >-
    Intracranial (basal ganglia) calcification, a recognized consequence of
    long-standing hypoparathyroidism, was found to be more frequent in HDR than
    initially reported.
  phenotype_term:
    preferred_term: Basal ganglia calcification
    term:
      id: HP:0002135
      label: Basal ganglia calcification
  evidence:
  - reference: PMID:38940299
    reference_title: "HDR syndrome: Large cohort and systematic review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Some conditions such as hearing loss are almost always present, while
      others described as rare initially, do not seem to be so rare after all
      (genital malformations and basal ganglia calcifications).
    explanation: >-
      Cohort plus systematic review reporting basal ganglia calcification as
      a not-rare feature.
- category: Otologic
  name: Bilateral sensorineural hearing impairment
  frequency: VERY_FREQUENT
  description: >-
    The most constant feature (93-100%). Usually congenital or early-onset,
    bilateral and symmetric, of mild-to-severe or profound degree, and in
    some patients detected only by audiometry in adulthood. It is cochlear in
    origin with an outer hair cell signature.
  phenotype_term:
    preferred_term: Bilateral sensorineural hearing impairment
    term:
      id: HP:0008619
      label: Bilateral sensorineural hearing impairment
  evidence:
  - reference: PMID:32442337
    reference_title: "Hypoparathyroidism, deafness, and renal dysplasia syndrome: 20 Years after the identification of the first GATA3 mutations."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: REVIEW_SYNTHESIS
    snippet: >-
      The most frequently observed abnormality was deafness (93%), followed by
      hypoparathyroidism (87%) and renal defects (61%).
    explanation: >-
      Deafness is the most frequent component.
  - reference: PMID:24434941
    reference_title: "Audiometric characteristics of a dutch family with a new mutation in GATA3 causing HDR syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Their hearing impairment was congenital, bilateral and symmetric.
      Audiograms showed mild-to-moderate hearing impairment with a flat
      audiogram configuration.
    explanation: >-
      Describes the audiometric phenotype: congenital, bilateral, symmetric.
  - reference: PMID:27387476
    reference_title: "Clinical and mutational spectrum of hypoparathyroidism, deafness and renal dysplasia syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Sensorineural deafness was consistently diagnosed, ranging from clinical
      hearing loss since infancy in seven patients to deafness detected only by
      audiometry in adulthood in one single patient.
    explanation: >-
      Shows the range of severity and age at detection.
- category: Renal
  name: Renal dysplasia
  frequency: FREQUENT
  description: >-
    Renal anomalies occur in about 60% of reported patients and are
    predominantly dysplastic in nature; they vary widely between and within
    families.
  phenotype_term:
    preferred_term: Renal dysplasia
    term:
      id: HP:0000110
      label: Renal dysplasia
  evidence:
  - reference: PMID:27387476
    reference_title: "Clinical and mutational spectrum of hypoparathyroidism, deafness and renal dysplasia syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Renal abnormalities observed in six patients were diverse and of
      dysplastic nature.
    explanation: >-
      Dysplastic character of the renal anomalies in a case series.
  - reference: PMID:32442337
    reference_title: "Hypoparathyroidism, deafness, and renal dysplasia syndrome: 20 Years after the identification of the first GATA3 mutations."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: REVIEW_SYNTHESIS
    snippet: >-
      The most frequently observed abnormality was deafness (93%), followed by
      hypoparathyroidism (87%) and renal defects (61%).
    explanation: >-
      Frequency of renal defects across reported patients (FREQUENT band).
- category: Renal
  name: Renal hypoplasia
  description: >-
    Unilateral renal hypoplasia is among the reported structural anomalies.
  phenotype_term:
    preferred_term: Renal hypoplasia
    term:
      id: HP:0000089
      label: Renal hypoplasia
  evidence:
  - reference: PMID:26800885
    reference_title: "HDR syndrome in a Japanese girl with biliary atresia: a case report."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      her mother had sensorineural deafness, a low serum calcium level (2.1
      mmol/l), hypoplastic left kidney, and a past history of an operation for
      right vesicoureteral reflux
    explanation: >-
      Hypoplastic kidney in a GATA3 variant carrier with the other HDR features.
- category: Renal
  name: Multicystic kidney dysplasia
  description: >-
    Multicystic dysplastic kidney has been reported, requiring nephrectomy in
    infancy in one case.
  phenotype_term:
    preferred_term: Multicystic kidney dysplasia
    term:
      id: HP:0000003
      label: Multicystic kidney dysplasia
  evidence:
  - reference: PMID:37561279
    reference_title: "Clinical and molecular characteristics of two Italian kindreds with hypoparathyroidism, deafness and renal dysplasia (HDR) syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      his past medical history was remarkable for right nephrectomy at the age
      of 4 months due to multicystic renal disease
    explanation: >-
      Multicystic renal disease in infancy in an HDR proband.
- category: Renal
  name: Renal cyst
  description: >-
    Simple or bilateral renal cysts are found on imaging in some patients.
  phenotype_term:
    preferred_term: Renal cyst
    term:
      id: HP:0000107
      label: Renal cyst
  evidence:
  - reference: PMID:37561279
    reference_title: "Clinical and molecular characteristics of two Italian kindreds with hypoparathyroidism, deafness and renal dysplasia (HDR) syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Abdomen ultrasound showed bilateral renal cysts.
    explanation: >-
      Bilateral renal cysts in an HDR proband.
- category: Renal
  name: Vesicoureteral reflux
  description: >-
    Vesicoureteral reflux is part of the urinary tract spectrum of HDR and is
    recommended as a monitoring target in follow-up.
  phenotype_term:
    preferred_term: Vesicoureteral reflux
    term:
      id: HP:0000076
      label: Vesicoureteral reflux
  evidence:
  - reference: PMID:26800885
    reference_title: "HDR syndrome in a Japanese girl with biliary atresia: a case report."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      her mother had sensorineural deafness, a low serum calcium level (2.1
      mmol/l), hypoplastic left kidney, and a past history of an operation for
      right vesicoureteral reflux
    explanation: >-
      Surgically treated vesicoureteral reflux in a GATA3 variant carrier.
  - reference: PMID:38940299
    reference_title: "HDR syndrome: Large cohort and systematic review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      follow up of patients with HDR syndrome should include monitoring of
      parathyroid function and vesicoureteral reflux in order to prevent
      complications
    explanation: >-
      Cohort-based recommendation to monitor vesicoureteral reflux, reflecting
      its recurrence in HDR.
- category: Renal
  name: Unilateral renal agenesis
  description: >-
    Absence of one kidney, reported in 1 of 9 patients with renal
    manifestations in a kidney disease cohort.
  phenotype_term:
    preferred_term: Unilateral renal agenesis
    term:
      id: HP:0000122
      label: Unilateral renal agenesis
  evidence:
  - reference: PMID:42595857
    reference_title: "Clinical and genetic characteristics of hypoparathyroidism, deafness, and renal dysplasia syndrome in a chronic kidney disease cohort."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Unilateral kidney agenesis and hydronephrosis were observed in 11.1%
      (1/9) of patients.
    explanation: >-
      Frequency of unilateral renal agenesis among patients with renal
      manifestations.
- category: Renal
  name: Hydronephrosis
  description: >-
    Hydronephrosis, reported with a hypoplastic kidney in 1 of 9 patients with
    renal manifestations in a kidney disease cohort.
  phenotype_term:
    preferred_term: Hydronephrosis
    term:
      id: HP:0000126
      label: Hydronephrosis
  evidence:
  - reference: PMID:42595857
    reference_title: "Clinical and genetic characteristics of hypoparathyroidism, deafness, and renal dysplasia syndrome in a chronic kidney disease cohort."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Unilateral kidney agenesis and hydronephrosis were observed in 11.1%
      (1/9) of patients.
    explanation: >-
      Frequency of hydronephrosis among patients with renal manifestations.
- category: Renal
  name: Nephrotic range proteinuria
  description: >-
    Proteinuria in the nephrotic range marks glomerular involvement and may
    precede progression to end-stage kidney disease. A
    self-limiting nephrotic syndrome with diffuse proliferative
    glomerulonephritis has also been reported.
  phenotype_term:
    preferred_term: Nephrotic range proteinuria
    term:
      id: HP:0012593
      label: Nephrotic range proteinuria
  evidence:
  - reference: PMID:27387476
    reference_title: "Clinical and mutational spectrum of hypoparathyroidism, deafness and renal dysplasia syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Three patients displayed nephrotic-range proteinuria and reached end-stage
      renal disease (ESRD) between the ages of 19 and 61 years, whilst lesions
      of focal and segmental glomerulosclerosis were histologically
      demonstrated in one of them.
    explanation: >-
      Nephrotic-range proteinuria in three of eight patients.
  - reference: PMID:23052618
    reference_title: "Renal phenotypic variability in HDR syndrome: glomerular nephropathy as a novel finding."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      atypical renal symptoms (diffuse proliferative glomerulonephritis
      characterized by a self-limiting nephrotic syndrome)
    explanation: >-
      Glomerular nephropathy with nephrotic syndrome in an HDR patient.
- category: Renal
  name: Focal segmental glomerulosclerosis
  description: >-
    Focal segmental glomerulosclerosis has been shown histologically in a
    patient with nephrotic-range proteinuria who progressed to ESRD.
  phenotype_term:
    preferred_term: Focal segmental glomerulosclerosis
    term:
      id: HP:0000097
      label: Focal segmental glomerulosclerosis
  evidence:
  - reference: PMID:27387476
    reference_title: "Clinical and mutational spectrum of hypoparathyroidism, deafness and renal dysplasia syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Three patients displayed nephrotic-range proteinuria and reached end-stage
      renal disease (ESRD) between the ages of 19 and 61 years, whilst lesions
      of focal and segmental glomerulosclerosis were histologically
      demonstrated in one of them.
    explanation: >-
      Histologically proven FSGS in one patient.
- category: Renal
  name: Nephrocalcinosis
  description: >-
    Nephrocalcinosis has been reported with renal insufficiency; in
    hypoparathyroidism it is usually attributed to hypercalciuria, which
    calcium and active vitamin D treatment aggravates.
  phenotype_term:
    preferred_term: Nephrocalcinosis
    term:
      id: HP:0000121
      label: Nephrocalcinosis
  evidence:
  - reference: PMID:23052618
    reference_title: "Renal phenotypic variability in HDR syndrome: glomerular nephropathy as a novel finding."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      bilateral sensorineural deafness and renal insufficiency associated with
      nephrocalcinosis
    explanation: >-
      Nephrocalcinosis in an HDR patient with renal insufficiency.
- category: Renal
  name: Stage 5 chronic kidney disease
  frequency: OCCASIONAL
  description: >-
    About 10% of reported patients reach end-stage kidney disease, at ages
    ranging from adolescence to the seventh decade. Kidney transplantation has
    been successful.
  phenotype_term:
    preferred_term: End-stage kidney disease
    term:
      id: HP:0003774
      label: Stage 5 chronic kidney disease
  evidence:
  - reference: PMID:27387476
    reference_title: "Clinical and mutational spectrum of hypoparathyroidism, deafness and renal dysplasia syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: REVIEW_SYNTHESIS
    snippet: >-
      Overall, 10% of patients had reached ESRD.
    explanation: >-
      Pooled frequency of ESRD across reported patients.
- category: Genitourinary
  name: Female genital tract anomaly
  frequency: FREQUENT
  description: >-
    Congenital anomalies of the female genital tract were present in 3 of 8
    female patients (37.5%) in a kidney disease cohort, and genital
    malformations were found to be more common than first thought in a larger
    cohort and systematic review. The anomalies differ between patients: the
    three reported in the kidney cohort were vaginal atresia, uterine
    duplication and bicornuate uterus. Only bicornuate uterus is curated as a
    separate phenotype. Uterine duplication is not, because the source does not
    say which form of duplication was present. Vaginal atresia is not, because
    it occurred in the one patient (SC230) whose GATA3 variant, p.(Cys339Phe),
    is classified as of uncertain significance; that patient is also counted
    in the 3/8 figure.
  phenotype_term:
    preferred_term: Female genital tract anomaly
    coarse_binding_basis: VARIABLE_SPECTRUM
    term:
      id: HP:0010460
      label: Abnormality of the female genitalia
  evidence:
  - reference: PMID:42595857
    reference_title: "Clinical and genetic characteristics of hypoparathyroidism, deafness, and renal dysplasia syndrome in a chronic kidney disease cohort."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Among the extrarenal manifestations, female genital tract anomalies were
      present in 37.5% of female patients (3/8)
    explanation: >-
      Frequency of female genital tract anomalies among female GATA3 variant
      carriers in the cohort (FREQUENT band, females only). The 3/8 includes
      one carrier of a variant of uncertain significance; excluding her gives
      2/7 (29%), just below the 30% FREQUENT threshold, so the band is
      approximate.
  - reference: PMID:42595857
    reference_title: "Clinical and genetic characteristics of hypoparathyroidism, deafness, and renal dysplasia syndrome in a chronic kidney disease cohort."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Congenital anomalies of the female genital tract were observed in several
      patients, consistent with previous studies
    explanation: >-
      The authors place their finding alongside earlier reports.
  - reference: PMID:38940299
    reference_title: "HDR syndrome: Large cohort and systematic review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Some conditions such as hearing loss are almost always present, while
      others described as rare initially, do not seem to be so rare after all
      (genital malformations and basal ganglia calcifications).
    explanation: >-
      Independent cohort and review reporting genital malformations as a
      recurrent HDR feature.
- category: Genitourinary
  name: Bicornuate uterus
  description: >-
    Reported in an affected mother carrying the familial GATA3 variant (Table 1
    of the kidney disease cohort, patient SC1125m).
  phenotype_term:
    preferred_term: Bicornuate uterus
    term:
      id: HP:0000813
      label: Bicornuate uterus
  evidence:
  - reference: PMID:42595857
    reference_title: "Clinical and genetic characteristics of hypoparathyroidism, deafness, and renal dysplasia syndrome in a chronic kidney disease cohort."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Decreased kidney func- tion Bicornuate uterus
    explanation: >-
      Table 1 row for patient SC1125m, listing decreased kidney function and
      bicornuate uterus.
genetic:
- name: GATA3
  gene_term:
    preferred_term: GATA3
    term:
      id: hgnc:4172
      label: GATA3
  association: Heterozygous loss-of-function variants or whole-gene deletion
  relationship_type: CAUSATIVE
  variant_origin: GERMLINE
  inheritance:
  - name: Autosomal Dominant
    inheritance_term:
      preferred_term: Autosomal dominant inheritance
      term:
        id: HP:0000006
        label: Autosomal dominant inheritance
  notes: >-
    GATA3 maps to 10p14-p15. Larger terminal 10p deletions that remove GATA3
    produce HDR features as part of a contiguous gene syndrome that can overlap
    with the DiGeorge-like 10p13-p14 region. Missense variants cluster in the
    two zinc-finger domains. Patients with whole-gene deletions and
    protein-truncating variants are diagnosed earlier than those with missense
    variants. A missense variant with dominant-negative activity in vitro has
    been reported, but haploinsufficiency is the established mechanism.
    Isolated hypoparathyroidism without deafness or renal disease has not been
    associated with GATA3 variants.
  evidence:
  - reference: PMID:10935639
    reference_title: "GATA3 haplo-insufficiency causes human HDR syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      We have performed deletion-mapping studies in two HDR patients, and here
      we define a critical 200-kilobase region which contains the GATA3 gene.
    explanation: >-
      Deletion mapping to GATA3, the first line of evidence for the gene.
  - reference: PMID:32442337
    reference_title: "Hypoparathyroidism, deafness, and renal dysplasia syndrome: 20 Years after the identification of the first GATA3 mutations."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: REVIEW_SYNTHESIS
    snippet: >-
      Missense mutations were found to cluster in the regions encoding the two
      GATA3 zinc-finger domains.
    explanation: >-
      Location of missense variants, stated in the notes.
  - reference: PMID:32442337
    reference_title: "Hypoparathyroidism, deafness, and renal dysplasia syndrome: 20 Years after the identification of the first GATA3 mutations."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: REVIEW_SYNTHESIS
    snippet: >-
      However, patients with whole-gene deletions and protein-truncating
      mutations were diagnosed earlier than patients with missense mutations.
    explanation: >-
      The genotype-phenotype observation stated in the notes.
  - reference: PMID:21120445
    reference_title: "Novel dominant-negative mutant of GATA3 in HDR syndrome."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      Moreover, mutated GATA3 exerted a dominant-negative effect over the
      transactivation activity of wild-type GATA3.
    explanation: >-
      The single reported dominant-negative missense allele (Cys321Ser).
  - reference: PMID:17210674
    reference_title: "Functional characterization of GATA3 mutations causing the hypoparathyroidism-deafness-renal (HDR) dysplasia syndrome: insight into mechanisms of DNA binding by the GATA3 transcription factor."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      No mutations were identified in patients with isolated hypoparathyroidism,
      thereby indicating that GATA3 abnormalities are more likely to result in
      two or more of the phenotypic features of the HDR syndrome and not in one,
      such as isolated hypoparathyroidism.
    explanation: >-
      Negative screening of 14 isolated hypoparathyroidism patients.
prevalence:
- population: Worldwide
  measure_type: CASES_IN_LITERATURE
  prevalence_class: RARE
  notes: >-
    No population prevalence estimate exists. By 2020, GATA3 variants had been
    reported in 124 families (177 patients). In a Japanese cohort of 1254
    families tested for chronic kidney disease, 7 families (10 patients) had
    pathogenic or likely pathogenic GATA3 variants.
  evidence:
  - reference: PMID:32442337
    reference_title: "Hypoparathyroidism, deafness, and renal dysplasia syndrome: 20 Years after the identification of the first GATA3 mutations."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: REVIEW_SYNTHESIS
    snippet: >-
      In the last 20 years, since the identification of the genetic cause of
      the HDR syndrome, GATA3 mutations have been reported in 124 families (177
      patients).
    explanation: >-
      Count of reported families and patients.
  - reference: PMID:42595857
    reference_title: "Clinical and genetic characteristics of hypoparathyroidism, deafness, and renal dysplasia syndrome in a chronic kidney disease cohort."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Among 1254 families with CKD, pathogenic or likely pathogenic GATA3
      variants were identified in 10 patients (seven families).
    explanation: >-
      Diagnostic yield of GATA3 in a CKD genetic-testing cohort.
diagnosis:
- name: Clinical and Molecular Diagnosis of HDR Syndrome
  description: >-
    HDR should be considered in any patient with two of the three components,
    and in particular in hypoparathyroidism with deafness whether or not renal
    disease is present, and in chronic kidney disease with sensorineural
    deafness. Apparently idiopathic hypoparathyroidism warrants evaluation of
    hearing and kidneys. The diagnosis is confirmed by a heterozygous
    pathogenic GATA3 variant; copy-number analysis is required because about
    15% of variants are whole-gene deletions. Relatives should be screened for
    parathyroid, auditory and renal involvement given the variable expressivity.
  evidence:
  - reference: PMID:27387476
    reference_title: "Clinical and mutational spectrum of hypoparathyroidism, deafness and renal dysplasia syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Diagnosis of HDR should be considered in any patient with
      hypoparathyroidism and deafness, whether associated with renal
      abnormalities or not. HDR diagnosis is established through identification
      of a mutation in the GATA-3 gene.
    explanation: >-
      Diagnostic recommendation and confirmation by GATA3 testing.
  - reference: PMID:42595857
    reference_title: "Clinical and genetic characteristics of hypoparathyroidism, deafness, and renal dysplasia syndrome in a chronic kidney disease cohort."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      In patients with CKD and sensorineural deafness, HDR syndrome should be
      considered, and comprehensive genetic testing, including copy number
      analysis, is essential for accurate diagnosis.
    explanation: >-
      Supports testing in CKD with deafness and the need for copy-number
      analysis.
  - reference: PMID:37561279
    reference_title: "Clinical and molecular characteristics of two Italian kindreds with hypoparathyroidism, deafness and renal dysplasia (HDR) syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      HDR syndrome is a rare cause of hypoparathyroidism and must be excluded
      in all patients with apparently idiopathic hypoparathyroidism.
    explanation: >-
      Supports evaluating idiopathic hypoparathyroidism for HDR.
  - reference: PMID:29663634
    reference_title: "Barakat syndrome revisited."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: REVIEW_SYNTHESIS
    snippet: >-
      We suggest that the diagnosis could be confirmed in patients who have all
      three components, and in those who have two components with a positive
      family history.
    explanation: >-
      Proposed clinical diagnostic criteria from a review of 180 cases.
treatments:
- name: Calcium and Active Vitamin D Supplementation
  description: >-
    Hypocalcemia due to hypoparathyroidism is treated as in other forms of
    hypoparathyroidism, with oral calcium and an active vitamin D analogue
    such as calcitriol, aiming for low-normal serum calcium to limit
    hypercalciuria and nephrocalcinosis, a particular concern when the
    kidneys are already abnormal.
  therapeutic_modality: SMALL_MOLECULE
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: calcium carbonate
      term:
        id: CHEBI:3311
        label: calcium carbonate
    - preferred_term: calcitriol
      term:
        id: CHEBI:17823
        label: calcitriol
  target_mechanisms:
  - target: Hypocalcemia
    description: >-
      Replaces calcium and bypasses the lost PTH-dependent activation of
      vitamin D.
  evidence:
  - reference: PMID:37908274
    reference_title: "Hypoparathyroidism, Sensorineural Deafness, and Renal Disease Syndrome Presenting With Febrile Seizures and Hypocalcemia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Hypocalcemia was responsive to calcium carbonate and calcitriol treatment.
    explanation: >-
      Case report of response of HDR-related hypocalcemia to calcium carbonate
      and calcitriol.
- name: Parathyroid Hormone Replacement (Palopegteriparatide)
  description: >-
    Conventional calcium and active vitamin D does not replace the renal and
    skeletal actions of PTH and carries a risk of hypercalciuria,
    nephrocalcinosis and stones. Palopegteriparatide, a once-daily prodrug of
    PTH(1-34), is approved for chronic hypoparathyroidism as a replacement
    therapy and in the phase 3 PaTHway trial normalized urinary calcium and was
    associated with improved eGFR. The evidence is from adults with chronic
    hypoparathyroidism of mixed causes, not specifically HDR; it is relevant here
    because HDR patients often have structurally abnormal kidneys.
  therapeutic_modality: PEPTIDE
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: palopegteriparatide
      term:
        id: CHEBI:759036
        label: palopegteriparatide
  target_mechanisms:
  - target: Deficient Parathyroid Hormone Secretion
    description: >-
      Replaces the missing hormone rather than compensating for its effects.
  evidence:
  - reference: PMID:28857066
    reference_title: "Hypoparathyroidism."
    supports: SUPPORT
    evidence_source: OTHER
    quote_role: REVIEW_SYNTHESIS
    snippet: >-
      Conventional treatment includes activated vitamin D and/or calcium
      supplements, but this treatment does not fully replace the functions of
      PTH and can lead to short-term problems (such as hypocalcaemia,
      hypercalcaemia and increased urinary calcium excretion) and long-term
      complications (which include nephrocalcinosis, kidney stones and brain
      calcifications).
    explanation: >-
      The limitation of conventional therapy that motivates PTH replacement.
  - reference: PMID:42166177
    reference_title: "Sustained improvement in renal function with palopegteriparatide in adults with chronic hypoparathyroidism: 2-year results from the phase 3 PaTHway-trial."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Palopegteriparatide treatment normalized mean (SD) 24-h urine calcium
      within 26 wk and maintained levels below 250 mg/d through Week 104
    explanation: >-
      Trial evidence in chronic hypoparathyroidism of any cause (not HDR
      specifically) that PTH replacement controls hypercalciuria.
  - reference: PMID:39987371
    reference_title: "PTH Substitution Therapy for Chronic Hypoparathyroidism: PTH 1-84 and Palopegteriparatide."
    supports: SUPPORT
    evidence_source: OTHER
    quote_role: REVIEW_SYNTHESIS
    snippet: >-
      Recently, the Food & Drug Administration and the European Medicines
      Agency approved palopegteriparatide as the first true replacement therapy
      for hypoPT management.
    explanation: >-
      Regulatory approval status for hypoparathyroidism in general.
- name: Hearing Rehabilitation (Hearing Aids or Cochlear Implantation)
  description: >-
    Hearing should be assessed as early as possible. Management follows that
    of other sensorineural hearing loss: hearing aids for mild-to-moderate loss
    and cochlear implantation for severe-to-profound loss.
  therapeutic_modality: DEVICE
  treatment_term:
    preferred_term: hearing device fitting and auditory rehabilitation
    term:
      id: NCIT:C15315
      label: Rehabilitation
    qualifiers:
    - predicate:
        preferred_term: medical device
        term:
          id: NCIT:C16830
          label: Medical Device
      value:
        preferred_term: hearing aid
        term:
          id: NCIT:C183182
          label: Hearing Aid
  target_mechanisms:
  - target: Bilateral sensorineural hearing impairment
  evidence:
  - reference: PMID:38940299
    reference_title: "HDR syndrome: Large cohort and systematic review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      As mentioned in the literature, hearing function should always be
      assessed as early as possible
    explanation: >-
      Recommendation for early hearing assessment, the entry point to hearing
      rehabilitation.
  - reference: PMID:29073906
    reference_title: "HDR syndrome with a novel mutation in GATA3 mimicking a congenital X-linked stapes gusher: a case report."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      A 14-month-old boy, with sensorineural hearing loss in both ears, showed
      typical radiological features of X-linked stapes gusher on preoperative
      temporal bone computed tomography (CT) for cochlear implantations.
    explanation: >-
      An HDR infant evaluated for cochlear implantation; documents the use of
      implantation in this disease, not its outcome.
- name: Kidney Transplantation
  description: >-
    For patients reaching end-stage kidney disease, kidney transplantation has
    been performed with long-term success, including a living related graft
    functioning for 26 years.
  therapeutic_modality: SURGERY
  treatment_term:
    preferred_term: kidney transplantation
    term:
      id: NCIT:C15265
      label: Kidney Transplantation
  target_mechanisms:
  - target: Stage 5 chronic kidney disease
  evidence:
  - reference: PMID:41064049
    reference_title: "Long-Term Renal Transplant Success Is Possible in Hypoparathyroidism, Sensorineural Deafness, and Renal Dysplasia Syndrome: A Case Report."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      He had a living donor kidney transplant at age 47 that was well tolerated
      until age 73, and he is now listed for a repeat transplant.
    explanation: >-
      Long-term graft survival after transplantation in HDR.
  - reference: PMID:41064049
    reference_title: "Long-Term Renal Transplant Success Is Possible in Hypoparathyroidism, Sensorineural Deafness, and Renal Dysplasia Syndrome: A Case Report."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Current limited evidence suggests kidney transplantation should be
      readily offered to individuals with end-stage renal disease due to HDR
      syndrome.
    explanation: >-
      Authors' recommendation, based on limited case evidence.
differential_diagnoses:
- name: 22q11.2 deletion syndrome
  description: >-
    Shares hypoparathyroidism and can include renal anomalies and hearing
    loss; distinguished by conotruncal heart defects, immunodeficiency and
    palatal anomalies. Terminal 10p deletions give an overlapping
    DiGeorge-like picture.
  disease_term:
    preferred_term: 22q11.2 deletion syndrome
    term:
      id: MONDO:0018923
      label: 22q11.2 deletion syndrome
  evidence:
  - reference: PMID:10935639
    reference_title: "GATA3 haplo-insufficiency causes human HDR syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Terminal deletions of chromosome 10p result in a DiGeorge-like phenotype
      that includes hypoparathyroidism, heart defects, immune deficiency,
      deafness and renal malformations.
    explanation: >-
      Documents the phenotypic overlap between 10p deletions (including GATA3)
      and DiGeorge syndrome.
- name: Alport syndrome
  description: >-
    Combines sensorineural hearing loss with progressive kidney disease and can
    be misdiagnosed for HDR in adults; lacks hypoparathyroidism and congenital
    renal malformation, and has ocular findings and type IV collagen variants.
  disease_term:
    preferred_term: Alport syndrome
    term:
      id: MONDO:0018965
      label: Alport syndrome
  evidence:
  - reference: PMID:41064049
    reference_title: "Long-Term Renal Transplant Success Is Possible in Hypoparathyroidism, Sensorineural Deafness, and Renal Dysplasia Syndrome: A Case Report."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      This individual previously had a clinical diagnosis of Alport syndrome,
      but the presence of congenital symptoms in other family members suggested
      an alternative diagnosis.
    explanation: >-
      A documented misdiagnosis of HDR as Alport syndrome.
- name: Branchiootorenal syndrome
  description: >-
    Combines hearing loss with renal dysplasia or hypoplasia, but hearing loss
    is often conductive or mixed, branchial and ear malformations are present,
    and parathyroid function is normal.
  disease_term:
    preferred_term: branchiootorenal syndrome 1
    term:
      id: MONDO:0007236
      label: branchiootorenal syndrome 1
  evidence:
  - reference: PMID:42595857
    reference_title: "Clinical and genetic characteristics of hypoparathyroidism, deafness, and renal dysplasia syndrome in a chronic kidney disease cohort."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      In such cases, the major differential diagnoses include Alport syndrome,
      branchio-oto-renal syndrome
    explanation: >-
      Names branchio-oto-renal syndrome as a major differential for the
      deafness plus renal (DR) presentation of HDR. In the same cohort's Table
      1, several GATA3 variant carriers had a prior clinical diagnosis of BOR.
animal_models:
- name: Gata3 heterozygous knockout mouse
  species: Mouse
  genotype: Gata3 +/-
  publication: PMID:20484821
  description: >-
    The heterozygous null mouse is the genetic equivalent of HDR. Under a
    low-calcium, low-vitamin D diet it shows smaller parathyroids with low PTH
    and calcium; it has progressive cochlear hair cell degeneration with about
    30 dB hearing loss; and it has a mesangial precursor deficit with
    glomerular abnormalities. Homozygous nulls die in utero and lack
    parathyroid-thymus primordia and kidneys.
  modeled_mechanisms:
  - target: Parathyroid Gland Hypoplasia
    relationship: RECAPITULATES
    fidelity: MODERATE
    model_scale: TISSUE
    limitations: >-
      The parathyroid defect is exposed by dietary calcium and vitamin D
      restriction rather than being overt on a normal diet.
    evidence:
    - reference: PMID:20484821
      reference_title: "Gata3-deficient mice develop parathyroid abnormalities due to dysregulation of the parathyroid-specific transcription factor Gcm2."
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: >-
        Compared with their wild-type littermates, Gata3+/- mice had lower
        plasma concentrations of calcium and parathyroid hormone (PTH) and
        smaller parathyroid glands with a reduced Ki-67 proliferation rate.
      explanation: >-
        Heterozygous mice reproduce the hypoplastic parathyroid and low PTH.
  - target: Cochlear Outer Hair Cell Degeneration
    relationship: RECAPITULATES
    fidelity: HIGH
    model_scale: CELLULAR
    evidence:
    - reference: PMID:15207274
      reference_title: "Hearing loss following Gata3 haploinsufficiency is caused by cochlear disorder."
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: >-
        Auditory brainstem response (ABR) thresholds of alert heterozygous
        Gata3 mice, analyzed from 1 to 19 months of age, showed a hearing loss
        of 30 dB compared to wild-type littermates.
      explanation: >-
        Hearing loss in heterozygous mice, with cochlear origin.
  - target: Mesangial Cell Precursor Deficiency
    relationship: RECAPITULATES
    fidelity: MODERATE
    model_scale: CELLULAR
    evidence:
    - reference: PMID:31405951
      reference_title: "A Novel Role for GATA3 in Mesangial Cells in Glomerular Development and Injury."
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: >-
        In mice, we uncover that GATA3 is essential for normal glomerular
        development, and mice with haploinsufficiency of Gata3 have too few MC
        precursors and glomerular abnormalities.
      explanation: >-
        Heterozygous mice show the mesangial precursor deficit.
notes: >-
  No GeneReviews chapter exists for this disease (checked with
  `just check-genereviews --online`, Bookshelf index snapshot 2026-09-10).
  Rare additional features reported in single cases include diabetes mellitus,
  congenital heart defects, choanal atresia and biliary atresia; they are not
  modeled here as their relationship to GATA3 is not established.
📚

References & Deep Research

Deep Research

1

Deep research results are used as seeds for research; they do not undergo the same validation as the main records and may contain errors. How we use deep research.

Evaluations and curation notes (1)

Create: Hypoparathyroidism-Deafness-Renal Disease Syndrome · 2026-09-23T20:12:19Z · View source

New entry for HDR (Barakat) syndrome, MONDO:0007797, caused by heterozygous GATA3 loss of function. Curated 9 pathophysiology nodes in three organ branches from GATA3 haploinsufficiency: parathyroid (reduced GCM2 expression in progenitors, parathyroid hypoplasia, reduced PTH transactivation, deficient PTH secretion), cochlea (outer hair cell degeneration) and kidney (dysregulated nephric duct and ureteric bud development, mesangial precursor deficiency, glomerular injury and nephron loss). 20 HP-bound phenotypes, all with an incoming causal edge; GATA3 genetic record; autosomal dominant inheritance; CASES_IN_LITERATURE prevalence; diagnosis; four treatments (calcium plus calcitriol, palopegteriparatide, hearing rehabilitation, kidney transplantation); three differential diagnoses; the Gata3 heterozygous mouse as animal model. No GeneReviews chapter exists (just check-genereviews --online: NO_CHAPTER). One OpenScientist report was used: research/Hypoparathyroidism_Deafness_Renal_Disease_Syndrome-deep-research-openscientist.md. Its generation step failed at term validation on an OLS timeout, so reference and term validation were re-run with just validate-research-reference and just validate-research-terms: 28/28 references resolved, 4 quoted claims not matched (all abbreviated with ellipses; the unabbreviated source text was confirmed), 1 off-topic reference (PMID:15253763, not cited), 0 unresolved terms. just preflight-dr returned WARN because the hormone PTH is mentioned often; MONDO, OMIM 146255 and GATA3 all match. Most evidence comes from PubMed searches; from the report the entry takes PMID:31069810, PMID:28857066, PMID:39987371 and PMID:42166177. The palopegteriparatide evidence is from hypoparathyroidism of mixed causes, not HDR specifically, and says so. Validation: just validate-disorders passed (schema, terms, 75/75 snippets verified); check-causal-targets, check-entity-refs, check-duplicate-keys, check-coarse-phenotypes, check-qualifier-terms, check-snippet-length, check-title-snippets, check-snippet-grading and check-reference-titles all OK.

OpenScientist ▸
Key Findings
openscientist-autonomous 27 citations 2026-09-23T19:55:04.506063

Key Findings

Finding 1 — HDR is caused by GATA3 haploinsufficiency at 10p14

Van Esch et al. (2000) performed deletion mapping in two HDR patients and defined a critical ~200-kb region on 10p14–pter containing the GATA3 gene. They identified one nonsense mutation and two intragenic deletions predicting loss of function, and confirmed the mechanism by demonstrating absent DNA binding of the mutant GATA3 protein. This established GATA3 as the single causal gene and haploinsufficiency (a 50% loss of functional protein) as the disease mechanism. The authors concluded that "GATA3 is essential in the embryonic development of the parathyroids, auditory system and kidneys" (PMID: 10935639), directly linking the single gene to the three organs of the clinical triad. HDR is inherited in an autosomal-dominant fashion (OMIM #146255).

Finding 2 — GATA3 mutation spectrum and age-dependent penetrance

The 20-year review by Lemos & Thakker (2020) aggregated 124 families (177 patients) and defined the mutation spectrum: 40% frameshift indels, 23% missense, 14% nonsense, 6% splice-site, 1% in-frame indels, 15% whole-gene deletions, and 1% whole-gene duplication (PMID: 32442337). Missense mutations cluster in the two zinc-finger domains. Penetrance of the three cardinal features differs: deafness 93%, hypoparathyroidism 87%, renal defects 61%, with mean ages of diagnosis of 15.3, 7.5, and 14.0 years respectively. Whole-gene deletions and truncating mutations are diagnosed earlier than missense variants, consistent with a dosage/severity relationship.

Mutation type Frequency Notes
Frameshift indels 40% Truncating; typically LoF
Missense 23% Cluster in ZnF1/ZnF2
Nonsense 14% Truncating
Whole-gene deletions 15% Earlier diagnosis; may include contiguous genes
Splice-site 6%
In-frame indels 1%
Whole-gene duplication 1% Rare
Feature Penetrance Mean age at diagnosis
Deafness (sensorineural) 93% 15.3 y
Hypoparathyroidism 87% 7.5 y
Renal defects 61% 14.0 y

Finding 3 — Structural basis: two zinc fingers with distinct functions

GATA3 is a dual zinc-finger transcription factor. Functional dissection of HDR missense mutants established a division of labor: the C-terminal zinc finger (ZnF2) binds DNA, while the N-terminal zinc finger (ZnF1) stabilizes DNA binding and mediates interaction with the cofactor FOG (Friend of GATA) (PMID: 15705923). The ZnF1 missense mutant Thr272Ile reduced DNA-binding affinity, abolished interaction with ZnF1/ZnF6 of the cofactor FOG2, and reduced luciferase reporter activity by >65% (P<0.001) without disturbing nuclear localization (PMID: 19723756). The ZnF1 mutant R276P reduced GATA-motif binding affinity while retaining FOG interaction (PMID: 15705923). These mechanistic studies explain how point mutations produce partial loss of function equivalent to haploinsufficiency.

Finding 4 — Model organism: Gata3-null mice show renal and neural-crest defects

Gata3−/− mouse embryos die by ~11 days post-coitum from noradrenaline deficiency of the sympathetic nervous system (reduced Th and Dbh mRNA). Pharmacological rescue with catechol intermediates prolonged survival and unmasked late defects including renal hypoplasia and developmental defects in cephalic neural-crest-derived structures (PMID: 10835639). These phenotypes are directly relevant to the renal and craniofacial features of HDR and demonstrate that GATA3 is essential in multiple developmental lineages.

Finding 5 — HDR renal phenotype is diverse, dysplastic, and can progress to ESRD/FSGS

Belge et al. (2017) studied 8 patients from 5 families plus a literature review: sensorineural deafness in 100%, hypoparathyroidism in 6/8, renal abnormalities in 6/8, described as "diverse and of dysplastic nature" (PMID: 27387476). Three patients developed nephrotic-range proteinuria and reached ESRD between ages 19 and 61, with FSGS histologically demonstrated in one. The renal spectrum in HDR broadly includes renal dysplasia/hypoplasia, cysts, vesicoureteral reflux, agenesis, and hypocalciuric or proteinuric disease. Marked intrafamilial variability was noted (e.g., mother vs. son). This establishes renal disease as the most heterogeneous and prognostically important component of the triad.

Finding 6 — Mechanism of sensorineural deafness

Mouse studies delineate a multi-step cochlear mechanism. Conditional Gata3 knockout disrupts cochlear morphogenesis (shortened cochlear duct, fewer hair/supporting cells), fails to specify the prosensory domain, and causes apoptotic depletion of spiral ganglion neurons: "Loss of Gata3 function leads to the failure in the specification of prosensory domain and subsequently, to increased cell death in the cochlear duct" (PMID: 23666531). Postnatally, GATA3 is required for the biophysical maturation, growth, and innervation of inner hair cells and survival of outer hair cells; heterozygous loss causes progressive hearing loss modeling HDR (PMID: 31069810). Even with catecholamine rescue, Gata3-null ears show only partial morphogenesis — a cochlear duct forms but neurosensory development fails (PMID: 21553382), matching the human hearing phenotype.

Finding 7 — The GATA3 → GCM2/GCMB → PTH cascade underlies hypoparathyroidism

Grigorieva et al. (2010) provided the definitive parathyroid mechanism. Gata3+/− mice challenged with a low-calcium/vitamin-D-deficient diet showed higher mortality, lower plasma calcium and PTH, and smaller parathyroid glands with reduced Ki-67 proliferation. E11.5 Gata3+/− embryos had smaller parathyroid-thymus primordia with fewer Gcm2-expressing cells; Gata3−/− embryos showed no Gcm2 expression and gross defects of the 3rd/4th pharyngeal pouches with absent parathyroid-thymus primordia. EMSA, luciferase, and ChIP assays showed GATA3 binds a functional double-GATA motif in the GCMB (GCM2) promoter: "GATA3 is critical for the differentiation and survival of parathyroid progenitor cells and, with GCM2/B, forms part of a transcriptional cascade in parathyroid development and function" (PMID: 20484821).

Finding 8 — GATA3 acts within a Notch/Hedgehog network in the pharyngeal pouch

Figueiredo et al. (2016), using an avian model, placed GATA3/GCM2 parathyroid specification downstream of Hedgehog and dependent on Notch signaling. Hedgehog loss reduced the Gata3/Gcm2-expression domain at median/anterior pouch territories, and Notch impairment reduced Gcm2/Pth parathyroid-fated domains and compromised gland development (PMID: 27544844). GATA3 and GCM2 co-localize in the parathyroid-fated endoderm, embedding the HDR cascade within a conserved organogenesis network.

Finding 9 — Large 10p deletions produce a contiguous-gene DiGeorge-2 phenotype

Two non-overlapping regions on 10p have distinct consequences. The telomeric HDR1 region (10p14–pter, containing GATA3) causes the HDR triad, whereas the more proximal DGCR2 / DiGeorge critical region II (10p13–p14) is associated with congenital heart defects (notably atrial septal defect), thymus hypoplasia/aplasia (T-cell defect), facial dysmorphism, and developmental delay: "Haploinsufficiency of a more proximal region, located on 10p13-10p14, designated as DGCR2 is associated with congenital heart defects and thymus hypoplasia/aplasia or T cell defect" (PMID: 22407589). Patients with large terminal deletions may show both HDR and DiGeorge-2 features, and hypoparathyroidism-related hypocalcemia can worsen heart failure — one report noted hypocalcemia "lasted for three weeks and resulted in repeated episodes of heart failure" (PMID: 18795911).

Finding 10 — Germline HDR vs. somatic GATA3 alterations in cancer are distinct

HDR results from heterozygous germline loss-of-function. Separately, GATA3 is a recurrent somatic driver in breast cancer — mutated in ~8% of inflammatory breast cancers and frequently altered in luminal/ER+ tumors (PMID: 40378057) — and serves as an immunohistochemical lineage marker for breast/urothelial carcinoma. Importantly, no established increased cancer risk has been reported for constitutional HDR; the germline and somatic contexts are mechanistically separate.

Finding 11 — Treatment is organ-directed and symptomatic

There is no therapy that corrects GATA3 haploinsufficiency. Hypoparathyroidism is managed with oral calcium and activated vitamin D (calcitriol/alfacalcidol), targeting low-normal serum calcium to avoid hypercalciuria, nephrocalcinosis, and stones — conventional treatment "does not fully replace the functions of PTH and can lead to … nephrocalcinosis, kidney stones and brain calcifications" (PMID: 28857066). PTH-replacement therapy has advanced substantially: palopegteriparatide (TransCon PTH), a long-acting PTH(1-34) prodrug, was "approved … as the first true replacement therapy for hypoPT management" (PMID: 39987371). In the phase-3 PaTHway trial it produced a mean eGFR increase of 8.9 mL/min/1.73 m² (P<0.0001) sustained through 104 weeks (PMID: 42166177) — a renally relevant benefit for HDR patients. Deafness is managed with hearing aids/cochlear implants, and ESRD with dialysis and transplantation (long-term graft success is documented, PMID: 41064049).

Finding 12 — Zebrafish recapitulates the HDR triad

Pan et al. (2025) identified a heterozygous GATA3 missense variant p.Cys288Tyr (c.863G>A, exon 4, ZnF region) segregating with the complete triad in a Chinese family. In vivo zebrafish assays showed the variant "deleterious impact … on the gill buds, otoliths, and pronephros" (PMID: 39505798) — the piscine analogs of parathyroid, auditory, and renal tissues — validating zebrafish as a tractable HDR model that recapitulates all three organ systems.

Finding 13 — Diagnosis: biochemical triad plus GATA3 molecular/CMA testing

Diagnosis rests on (i) hypocalcemia with hyperphosphatemia and inappropriately low/normal PTH; (ii) bilateral sensorineural hearing loss on audiometry; and (iii) renal anomalies on ultrasound. Confirmation is by GATA3 sequencing and, for whole-gene deletions, chromosomal microarray/aCGH, MLPA, or FISH. Tanaka et al. (2026) used "targeted next-generation sequencing-based kidney disease panels … and copy number variations were assessed using array comparative genomic hybridization" (PMID: 42595857). The triad is frequently incomplete: in a CKD cohort, "only 40% exhibited the complete triad", with deafness and renal manifestations predominating (PMID: 42595857). Hypocalcemic seizures are a common presenting sign, and HDR can be misdiagnosed as Alport syndrome (PMID: 41064049).

Finding 14 — Extended phenotype and surveillance

Rive Le Gouard et al. (2024) reported 28 patients plus a systematic review and found that features "described as rare initially, do not seem to be so rare after all (genital malformations and basal ganglia calcifications)", while hearing loss is "almost always present" (PMID: 38940299). Missense pathogenic variants localize near the two zinc fingers. The authors recommend that "follow up of patients with HDR syndrome should include monitoring of parathyroid function and vesicoureteral reflux in order to prevent complications" (PMID: 38940299). Additional reported features include hypocalcemic seizures/tetany, nephrolithiasis/nephrocalcinosis, and rare associations such as juvenile idiopathic arthritis (PMID: 41190486).

Finding 15 — Phenotypic variability modulated by BMP and SHH

Swartz et al. (2021, zebrafish) showed gata3 is expressed in maxillary neural crest and required between 24–30 hpf for palate development, and that "gata3 expression in maxillary neural crest requires Bmp signaling and … blocking Bmp signaling … can phenocopy gata3 mutants"; GATA3 re-expression rescues Bmp-blockade defects, placing GATA3 downstream of BMP (PMID: 34033651). Shh signaling modulates the variable phenotypic output of the Bmp–Gata3 pathway, and even gata3-null mutants show highly variable craniofacial defects — a developmental basis for the variable expressivity seen clinically.

Complete Report by Research Template Section

1. Disease Information

HDR syndrome is a rare autosomal-dominant Mendelian disorder defined by the triad of hypoparathyroidism, sensorineural deafness, and renal disease/dysplasia. It was first described by Barakat in 1977 and molecularly resolved in 2000 with the identification of GATA3 haploinsufficiency (PMID: 10935639).

Key identifiers: MONDO:0007797 · OMIM #146255 · Orphanet ORPHA:2237 · gene GATA3 (HGNC:4172, NCBI Gene 2625). MeSH indexes it under hypoparathyroidism/sensorineural hearing loss/congenital abnormalities; ICD-10 maps approximately to E20.8 (other hypoparathyroidism) with additional codes for hearing loss and renal anomaly.

Synonyms: Barakat syndrome; HDR syndrome; hypoparathyroidism–sensorineural deafness–renal dysplasia syndrome; hypoparathyroidism–deafness–renal anomaly syndrome.

Data source: Knowledge here is derived from aggregated disease-level resources (OMIM, Orphanet), cohort/case-series literature (fewer than ~200–250 reported patients), and model-organism studies — not from large EHR datasets, reflecting the disease's rarity.

2. Etiology

  • Primary cause: monoallelic loss-of-function of GATA3 (10p14) — point mutations (frameshift, nonsense, missense, splice) or whole-gene/contiguous deletions (Findings 1–2).
  • Genetic risk factors: the causal locus is GATA3 itself; there are no established common susceptibility loci or modifier genes proven in humans, though developmental modifier pathways (BMP, SHH, Notch, Hedgehog) modulate expressivity in models (Findings 8, 15).
  • Environmental risk factors: none established as causal. Dietary calcium/vitamin-D status modulates the severity/penetrance of hypocalcemia (the Gata3+/− mouse becomes symptomatic only under low-calcium challenge, Finding 7) — a gene–environment interaction relevant to clinical decompensation rather than to disease origin.
  • Protective factors: none identified. There are no reported protective alleles.
  • Gene–environment interaction: low dietary calcium/vitamin-D unmasks latent hypoparathyroidism in the haploinsufficient state (Finding 7).

3. Phenotypes

Phenotype Type HPO term (suggested) Onset Frequency
Hypoparathyroidism / hypocalcemia Lab abnormality HP:0000829 / HP:0002901 Neonatal–childhood (mean 7.5 y) ~87%
Sensorineural hearing loss (bilateral) Clinical sign HP:0000407 Congenital–childhood (mean 15.3 y) ~93%
Renal dysplasia/hypoplasia/agenesis/cysts Physical/imaging HP:0000110 / HP:0000107 / HP:0000104 Congenital–adult (mean 14.0 y) ~61%
Hypocalcemic seizures/tetany Symptom HP:0002199 Neonatal–childhood Common presenting sign
Hyperphosphatemia Lab abnormality HP:0002905 Concurrent with hypoPT Frequent
Vesicoureteral reflux Clinical sign HP:0000076 Childhood Reported
Proteinuria / FSGS / ESRD Lab/pathology HP:0000093 / HP:0000097 / HP:0003774 Adult Subset (progressive)
Basal ganglia calcification Imaging HP:0002135 Adult Underrecognized
Genital/genitourinary malformation Physical HP:0000811 Congenital Underrecognized

Severity and progression are variable; hearing loss is often progressive and near-universally penetrant (Findings 2, 6, 14). Quality-of-life impact: deafness affects communication and development (mitigated by early cochlear implantation); hypoparathyroidism carries risk of seizures and lifelong medication burden; ESRD imposes dialysis/transplant burden. Disease-specific QoL instruments have not been reported; general hypoparathyroidism data indicate substantial symptom burden.

4. Genetic / Molecular Information

  • Causal gene: GATA3 (HGNC:4172; OMIM *131320; 10p14), a dual C4-type zinc-finger transcription factor.
  • Variant spectrum (Finding 2): 40% frameshift, 23% missense, 14% nonsense, 6% splice, 15% whole-gene deletions, 1% in-frame indels, 1% duplication. Missense variants cluster in ZnF1/ZnF2.
  • Variant classification: pathogenic/likely-pathogenic per ACMG for truncating and validated missense variants; functional assays (EMSA, luciferase, yeast two-hybrid, zebrafish) resolve VUS (Findings 3, 12).
  • Allele frequency: private/de novo or family-segregating; essentially absent from gnomAD (loss-of-function-intolerant gene).
  • Origin: germline; many de novo. (Somatic GATA3 alterations are a separate oncologic phenomenon, Finding 10.)
  • Functional consequence: loss of function / haploinsufficiency (Finding 1); some missense variants act via loss of DNA binding and/or loss of FOG cofactor interaction (Finding 3).
  • Modifier genes: GCM2/GCMB (downstream effector, Finding 7); BMP/SHH/Notch pathway components as developmental modifiers (Findings 8, 15).
  • Chromosomal abnormalities: 10p14–pter deletions of varying size; large terminal deletions extend into the DiGeorge-2 (DGCR2) region (Finding 9).

5. Environmental Information

No environmental, lifestyle, or infectious agents cause HDR. Dietary calcium/vitamin-D status modulates the clinical severity of hypocalcemia (Finding 7). No toxicological or occupational exposures are implicated.

6. Mechanism / Pathophysiology

Ordered causal chain (initiating lesion → clinical manifestation):

  1. A heterozygous loss-of-function lesion in GATA3 (point mutation or deletion) leads to ~50% reduction of functional GATA3 protein (haploinsufficiency) — demonstrated (PMID: 10935639).
  2. Reduced GATA3 dose results in insufficient transcriptional activity at GATA target loci during development — demonstrated in vitro via loss of DNA binding and FOG interaction (PMID: 15705923, PMID: 19723756).
  3. The dosage deficit crosses tissue-specific thresholds in three lineages, branching the mechanism:

Branch A — Parathyroid: Reduced GATA3 fails to fully activate the GCM2/GCMB promoter → fewer/hypoplastic parathyroid progenitors → reduced PTH synthesis → hypoparathyroidism → hypocalcemia + hyperphosphatemia → tetany/seizures (demonstrated in mouse, PMID: 20484821; embedded in Hedgehog/Notch pouch network, PMID: 27544844).

Branch B — Cochlea: Reduced GATA3 fails to specify the prosensory domain → increased apoptosis in the cochlear duct, defective hair-cell maturation/innervation, spiral-ganglion neuron loss → bilateral (often progressive) sensorineural deafness (demonstrated in mouse, PMID: 23666531, PMID: 31069810, PMID: 21553382).

Branch C — Kidney: Reduced GATA3 impairs metanephric/nephric development → renal dysplasia/hypoplasia/agenesis/cysts; in a subset, glomerular injury → proteinuria → FSGS → ESRD (human clinical + mouse, PMID: 27387476, PMID: 10835639).

  1. Modifier pathways (BMP upstream of GATA3; SHH/Hedgehog and Notch modulating output) tune the threshold in each tissue, inferred to explain the wide variable expressivity and incomplete triad (PMID: 34033651, PMID: 27544844).
         GATA3 LoF (10p14)  →  ~50% protein  →  sub-threshold transcription
                  │
┌─────────────────┼──────────────────────────┐
▼                 ▼                           ▼
  PARATHYROID          COCHLEA                       KIDNEY
  GATA3→GCM2/GCMB      prosensory spec. fails        metanephric dev. impaired
  →↓PTH progenitors    →hair-cell/SGN loss           →dysplasia/hypoplasia
  →hypoPT→↓Ca/↑PO4     →sensorineural deafness        →VUR, cysts; →FSGS/ESRD
  →seizures/tetany
▲                 ▲                           ▲
└── modifiers: BMP (upstream), SHH, Notch, Hedgehog tune thresholds ──┘

Molecular pathways / GO & CL suggestions: transcriptional regulation (GO:0006357), parathyroid gland development (GO:0060017), inner ear morphogenesis (GO:0042472), metanephros development (GO:0001656), pharyngeal system development. Cell types (CL): parathyroid chief cell (CL:0000446), cochlear hair cell / inner hair cell (CL:0000589 / CL:0002365), spiral ganglion neuron (CL:0000205), nephron progenitor/renal epithelial cells. Chemical entities (CHEBI): calcium ion (CHEBI:29108), phosphate, calcitriol (CHEBI:17823).

Immune involvement: GATA3 is also the master Th2 transcription factor; while the reviewed germline HDR literature does not establish primary immunodeficiency, rare autoimmune associations (JIA) have been reported and large 10p deletions cause thymic/T-cell defects via the DiGeorge-2 region (Findings 9, 14).

7. Anatomical Structures Affected

  • Organ level (primary): parathyroid glands (UBERON:0001132), inner ear/cochlea (UBERON:0001844), kidney (UBERON:0002113). Secondary: brain basal ganglia (calcifications, UBERON:0002420), heart (in DiGeorge-2 contiguous deletions), thymus (DiGeorge-2), genitalia.
  • Body systems: endocrine, auditory/nervous, urinary/renal.
  • Tissue/cell level: parathyroid chief cells; cochlear sensory epithelium (hair cells, supporting cells) and spiral ganglion neurons; renal metanephric epithelium/glomerular podocytes (FSGS).
  • Subcellular (GO CC): nucleus (GO:0005634) — GATA3 is a nuclear transcription factor; DNA-binding via zinc-finger domains.
  • Localization / lateralization: deafness and (typically) renal involvement are bilateral, though renal anomalies can be asymmetric/unilateral (e.g., unilateral agenesis).

8. Temporal Development

  • Onset: congenital to childhood; hypoparathyroidism often presents earliest (neonatal hypocalcemic seizures; mean 7.5 y), deafness may be congenital or progressive (mean 15.3 y), renal disease congenital-to-adult (mean 14.0 y) (Finding 2).
  • Onset pattern: developmental/congenital lesion with variable clinical unveiling; hypocalcemia can present acutely (seizure/tetany).
  • Progression: hearing loss often progressive; renal disease may be stable or progressive to ESRD; hypoparathyroidism is chronic and lifelong.
  • Disease course: chronic, lifelong; no spontaneous remission. Critical intervention windows: early audiologic intervention (cochlear implantation) and vigilant calcium/renal management.

9. Inheritance and Population

  • Inheritance: autosomal dominant; many de novo cases; germline (Finding 1).
  • Penetrance: high but incomplete and age-dependent; triad frequently incomplete (only ~40% complete in one cohort) (Findings 2, 13). Expressivity: highly variable, including intrafamilial (Findings 5, 14, 15).
  • Epidemiology: rare; fewer than ~200–250 patients reported in the literature; precise prevalence/incidence not established (Orphanet lists it as rare). No robust founder effect, sex bias, or specific ethnic predilection established; cases reported worldwide.
  • Consanguinity: not required (dominant). Carrier frequency: not applicable in the recessive sense; affected heterozygotes transmit with 50% risk.
  • Anticipation/mosaicism: no repeat-expansion mechanism; anticipation not a feature. Germline mosaicism is plausible but not systematically documented.

10. Diagnostics

  • Laboratory: low serum calcium, high phosphate, inappropriately low/normal intact PTH; check magnesium, 25-OH and 1,25-(OH)₂ vitamin D, urinary calcium, renal function (creatinine/eGFR), urinalysis for proteinuria.
  • Audiology: pure-tone audiometry / ABR confirming bilateral sensorineural hearing loss; temporal-bone imaging (may mimic X-linked stapes gusher, PMID: 29073906).
  • Imaging: renal ultrasound (dysplasia, hypoplasia, agenesis, cysts, reflux); brain CT for basal ganglia calcification.
  • Genetic testing: GATA3 single-gene sequencing; NGS kidney/deafness/hypoparathyroidism panels; CMA/aCGH, MLPA, or FISH for whole-gene and contiguous deletions (PMID: 42595857). Low-coverage WGS/WES can detect large 10p deletions (PMID: 40763967).
  • Clinical criteria / differential: diagnosis is clinical triad + molecular confirmation. Differential diagnosis: Alport syndrome (misdiagnosis reported, PMID: 41064049), DiGeorge/22q11 and 10p-DiGeorge-2 syndromes, isolated autosomal-dominant hypoparathyroidism, branchio-oto-renal syndrome, renal coloboma (PAX2) syndrome.
  • Screening: cascade genetic testing of at-risk relatives; hearing screening; renal imaging in mutation carriers.

11. Outcome / Prognosis

  • Survival/mortality: not a primary shortening of lifespan when managed; mortality risk is driven by complications of hypocalcemia (seizures, in DiGeorge-2 heart failure) and renal failure.
  • Morbidity: deafness (developmental/communication impact), lifelong hypoparathyroidism management, and CKD/ESRD are the main disabilities. Renal progression to ESRD is the principal long-term prognostic determinant (Finding 5).
  • Recovery/complications: hearing rehabilitated with implants; ESRD treatable by transplantation with documented long-term graft success (PMID: 41064049); complications of conventional calcium/vitamin-D therapy include nephrocalcinosis, stones, and brain calcification (PMID: 28857066).
  • Prognostic factors: genotype (whole-gene deletions/truncating variants diagnosed earlier); presence and progression of renal disease; adequacy of calcium/PTH management.

12. Treatment

Domain Intervention NCIT (suggested) Evidence
Hypoparathyroidism (conventional) Oral calcium + activated vitamin D (calcitriol/alfacalcidol), target low-normal Ca Calcium supplement; Calcitriol PMID: 28857066, PMID: 29633734
Hypoparathyroidism (replacement) rhPTH(1-84); palopegteriparatide (long-acting PTH(1-34) prodrug) Parathyroid Hormone; Teriparatide analog PMID: 39987371, PMID: 42166177, PMID: 42656047
Deafness Hearing aids; cochlear implantation Cochlear Implant PMID: 29073906
Renal (ESRD) Dialysis; kidney transplantation Kidney Transplantation PMID: 41064049

There is no gene-, cell-, or RNA-based disease-modifying therapy. Palopegteriparatide is notable for renal benefit: mean eGFR rose 8.9 mL/min/1.73 m² (P<0.0001) and 97% of patients became independent of conventional therapy in PaTHway; real-world data confirm reduced hypercalciuria and pill burden (PMID: 42656047). Management targets low-normal serum calcium to protect the kidney (Finding 11). No specific pharmacogenomic guidance exists for HDR.

13. Prevention

  • Primary prevention: not possible (Mendelian); genetic counseling for 50% transmission risk; prenatal/preimplantation genetic diagnosis available for known familial variants.
  • Secondary prevention: early hearing screening and renal imaging in carriers; biochemical surveillance for hypocalcemia.
  • Tertiary prevention (Finding 14): lifelong monitoring of parathyroid function and vesicoureteral reflux to prevent complications (PMID: 38940299); careful calcium/vitamin-D titration to avoid nephrocalcinosis and stones; early cochlear implantation.
  • Counseling: genetic counseling and cascade testing of relatives are central.

14. Other Species / Natural Disease

  • Taxonomy / orthologs: mouse Gata3 (NCBI Gene 14462; Mus musculus, NCBI:txid10090), zebrafish gata3 (Danio rerio, NCBI:txid7955), chicken/avian Gata3. GATA3 is deeply evolutionarily conserved.
  • Natural disease in other species: no spontaneous naturally occurring HDR-equivalent disorder is reported in companion animals/wildlife in the reviewed literature; the conservation of GATA3 function across vertebrates is inferred from experimental models rather than natural veterinary disease.
  • Comparative biology: mouse (renal + neural crest defects, catecholamine-dependent lethality), zebrafish (gill bud/otolith/pronephros), and avian (pharyngeal pouch) models all reproduce facets of the human triad (Findings 4, 8, 12), demonstrating conserved mechanisms.
  • Zoonotic potential: not applicable (non-infectious genetic disease).

15. Model Organisms

Model Type Key phenotype Recapitulation PMID
Gata3−/− mouse Knockout (mammalian) Embryonic lethal ~E11 (noradrenaline deficiency); rescued embryos show renal hypoplasia + neural-crest defects Partial (renal, craniofacial); lethality limits triad study PMID: 10835639
Gata3+/− mouse Heterozygous ↓PTH, ↓Ca, small parathyroids under low-Ca; progressive hearing loss Strong (parathyroid + auditory) — models haploinsufficiency PMID: 20484821, PMID: 31069810
Conditional Gata3 cKO mouse Conditional Prosensory specification failure, cochlear cell death, SGN loss Strong (cochlear mechanism) PMID: 23666531, PMID: 21553382
Zebrafish gata3 Knockdown/variant Gill bud, otolith, pronephros defects; craniofacial variability Strong — recapitulates all three organ analogs PMID: 39505798, PMID: 34033651
Avian (chick) pouch model In vivo developmental Gata3/Gcm2 domain reduced by Hedgehog/Notch loss Mechanistic (parathyroid specification network) PMID: 27544844

Limitations of models: mouse null lethality requires pharmacologic rescue that itself alters development; heterozygous mice need dietary challenge to reveal hypoparathyroidism (incomplete penetrance of biochemical phenotype at baseline). Resources: MGI (mouse), ZFIN (zebrafish). Model databases: MGI, IMPC, ZFIN.

Mechanistic Model / Interpretation

HDR is best understood as a single-gene, three-organ developmental dosage disease. GATA3 is a pleiotropic master transcription factor independently deployed in the parathyroid-fated pharyngeal endoderm, the cochlear prosensory epithelium, and the developing metanephros. A ~50% reduction in functional protein does not uniformly disable all targets; rather, each tissue has its own dosage threshold below which its developmental program fails. This threshold model explains the disease's defining clinical feature — variable, often incomplete expressivity — without invoking different mutations for different organs. The single best-characterized effector arm is the parathyroid GATA3 → GCM2/GCMB → PTH cascade, where GATA3 directly binds a double-GATA motif in the GCMB promoter; the cochlear arm operates through prosensory specification and hair-cell/neuron survival; the renal arm through metanephric morphogenesis with a downstream vulnerability to glomerular (FSGS) injury.

Superimposed on this core are two sources of phenotypic modulation. First, developmental modifier pathways — BMP acts upstream of GATA3, while SHH/Hedgehog and Notch tune its output — set tissue-specific thresholds and, when perturbed, shift the phenotype; this provides a molecular rationale for variable expressivity even among relatives sharing an identical variant. Second, deletion size matters: point mutations and small deletions produce "pure" HDR, whereas large 10p terminal deletions co-delete the DiGeorge-2 (DGCR2) region, adding cardiac (ASD), thymic/immune, and neurodevelopmental features. The germline HDR context is mechanistically distinct from the somatic GATA3 mutations that drive breast/urothelial cancers, and there is no evidence of elevated cancer risk in HDR.

Evidence Base

PMID Contribution Evidence type
10935639 Established GATA3 haploinsufficiency as cause; critical 200-kb 10p14 region Human genetics
32442337 124-family mutation spectrum + penetrance Human review
15705923, 19723756 ZnF1/ZnF2 functional roles; missense LoF mechanism In vitro
10835639 Gata3-null mouse renal/neural-crest defects Mouse
27387476 Dysplastic renal spectrum, FSGS/ESRD Human clinical
23666531, 31069810, 21553382 Cochlear mechanism of deafness Mouse
20484821 GATA3→GCMB→PTH cascade Mouse + in vitro
27544844 Hedgehog/Notch network in pouch Avian
22407589, 18795911, 15253763 DiGeorge-2 contiguous-gene distinction Human genetics
40378057 Somatic GATA3 in cancer (distinct from HDR) Human oncology
28857066, 39987371, 42166177, 42656047 Treatment: conventional + PTH replacement Clinical trials/reviews
39505798, 34033651 Zebrafish model; BMP/SHH modifiers Zebrafish
42595857, 38940299, 41064049 Diagnosis, extended phenotype, surveillance, transplant Human clinical

Limitations and Knowledge Gaps

  • Rarity limits epidemiology: precise prevalence, incidence, sex ratio, and geographic/ethnic distribution are not firmly established (<~250 reported patients); no large registry or EHR-scale dataset exists.
  • Genotype–phenotype correlation is imperfect: apart from a trend for earlier diagnosis with truncating/whole-gene-deletion variants, the molecular basis of which organs are affected in a given patient remains unpredictable; modifier evidence (BMP/SHH/Notch) is mostly from non-human models.
  • Renal progression predictors unknown: why only a subset progress to FSGS/ESRD is unclear; no validated prognostic biomarkers.
  • QoL data absent: no disease-specific quality-of-life instruments have been applied to HDR.
  • Human mechanistic data are indirect: the parathyroid and cochlear cascades are demonstrated largely in mice/zebrafish; direct human tissue confirmation is limited.
  • No natural veterinary disease characterized, and no disease-modifying therapy exists.

Proposed Follow-up Experiments / Actions

  1. Build an international HDR registry to define prevalence, penetrance, natural history, and renal-progression rates with longitudinal biomarker data.
  2. Genotype–phenotype and modifier study: correlate variant class/position (ZnF1 vs ZnF2, deletion size) with organ involvement and severity; genotype BMP/SHH/NOTCH pathway variants as candidate human modifiers.
  3. Renal prognostic biomarkers: prospectively track proteinuria, eGFR, and podocyte injury markers to identify predictors of FSGS/ESRD; evaluate whether early PTH-replacement (palopegteriparatide) preserves renal function in HDR specifically.
  4. iPSC/organoid models: derive patient iPSC-based kidney and inner-ear organoids to test tissue-specific dosage thresholds and screen threshold-raising interventions.
  5. Functional triage pipeline: standardize zebrafish (gill bud/otolith/pronephros) + in-vitro DNA-binding/FOG-interaction assays for rapid VUS reclassification.
  6. Clinical guideline development: codify surveillance (parathyroid function, VUR, hearing, renal imaging) and calcium-target management to minimize nephrocalcinosis and support early cochlear implantation.

Report compiled from 15 confirmed findings and 58 reviewed papers. Evidence types span human clinical genetics, mouse/zebrafish/avian model organisms, and in-vitro functional assays. HDR syndrome (MONDO:0007797; OMIM #146255) is caused by GATA3 haploinsufficiency at 10p14.

Artifacts

Term Validation

Checked with linkml-term-validator 0.4.5, through the ols: adapter.

Outcome Count
Terms checked 32
Resolved 30
Unresolved (possible confabulation) 0
Obsolete 0
Unverifiable 2
Terms whose name was checked 7
Terms named correctly 0
Terms named as a different term 7

Terms the report names something else

These identifiers resolve, so nothing about them looks wrong, and the ontology calls them something unrelated to what the report calls them. That usually means the identifier is not the one the sentence needs:

  • MONDO:0007797 (4 mentions) - the report calls it "if available"; MONDO calls it hypoparathyroidism-deafness-renal disease syndrome
  • HP:0000407 (1 mention) - the report calls it "Clinical sign"; HP calls it Sensorineural hearing impairment
  • HP:0002199 (1 mention) - the report calls it "Symptom"; HP calls it Hypocalcemic seizures
  • HP:0002905 (1 mention) - the report calls it "Lab abnormality"; HP calls it Hyperphosphatemia
  • HP:0000076 (1 mention) - the report calls it "Clinical sign"; HP calls it Vesicoureteral reflux
  • HP:0002135 (1 mention) - the report calls it "Imaging"; HP calls it Basal ganglia calcification
  • HP:0000811 (1 mention) - the report calls it "Physical"; HP calls it Abnormal external genitalia morphology

Prefixes with no resolver

Terms carrying these prefixes were not checked either way, because no configured ontology covers them. An unrecognised prefix may name an ontology this run could not reach as easily as one that does not exist, so nothing here is evidence of fabrication: ORPHA.

Reference Validation

Checked with linkml-reference-validator 0.2.1.

Outcome Count
References checked 28
Resolved 28
Unresolved (possible confabulation) 0
Unverifiable 0
Quoted claims checked 12
Quoted claims found in source 8
Quoted claims not found in source 4
References weighed for topical relevance 28
On topic 19
Off topic 1

Quotes not found in the cited source

Searched the abstract, any retrieved full text, and the title. A quote drawn from a part of the paper that was not retrieved will appear here too, so check before treating one as invented:

3 of these was searched against an abstract alone, with no full text retrieved - marked abstract only below. Where full text can be fetched, re-running with it will settle them; where the source publishes only a summary to PubMed, as GeneReviews chapters do, it will not, and the quote has to be checked by hand against the chapter itself.

  • PMID:28857066 (abstract only): "does not fully replace the functions of PTH and can lead to … nephrocalcinosis, kidney stones and brain calcifications"
  • closest text in source: "Conventional treatment includes activated vitamin D and/or calcium supplements, but this treatment does not fully replace the functions of PTH and can lead to short-term problems (such as hypocalcaemia, hypercalcaemia and increased urinary calcium excretion) and long-term complications (which include nephrocalcinosis, kidney stones and brain calcifications)"
  • PMID:39987371 (abstract only): "approved … as the first true replacement therapy for hypoPT management"
  • closest text in source: "Recently, the Food & Drug Administration and the European Medicines Agency approved palopegteriparatide as the first true replacement therapy for hypoPT management"
  • PMID:39505798 (abstract only): "deleterious impact … on the gill buds, otoliths, and pronephros"
  • closest text in source: "In vivo studies using a zebrafish animal model revealed the deleterious impact of the variant on the gill buds, otoliths, and pronephros"
  • PMID:42595857: "targeted next-generation sequencing-based kidney disease panels … and copy number variations were assessed using array comparative genomic hybridization"
  • closest text in source: "Targeted next-generation sequencing-based kidney disease panels were used, and copy number variations were assessed using array comparative genomic hybridization"

References that may not be about this subject

These identifiers resolve, so they are not fabrications, but the records they resolve to share almost none of this report's vocabulary. That is a clue and not a verdict - a paper can be relevant in ways its title and abstract do not spell out - so read them before deciding:

  • PMID:15253763 (1 mention) - Interstitial deletion of 10p and atrial septal defect in DiGeorge 2 syndrome.
  • shared terms: deletion, patient

Weighed against this report's own most characteristic terms: gata3, renal, hdr, hypoparathyroidism, deafness, hearing, disease, parathyroid, loss, cochlear, pth, deletion, phenotype, model, triad, patient, esrd, variant, development, function.