The First Korean Case of HDR Syndrome Confirmed by Clinical and Molecular Investigation

Hypoparathyroidism, deafness, and renal dysplasia (HDR) syndrome is a rare condition inherited as autosomal dominant trait and characterized by hypoparathyroidism, sensorineural deafness, and renal dysplasia. HDR syndrome is caused by haploinsufficiency of the GATA3 gene located on chromosome 10p15. Here, we report the case of a 32-day-old Korean male with HDR syndrome. He was presented due to repeated seizures over previous 3 days. The patient was born after 40 weeks of gestation with birth weight of 2930 g, and was the first-born baby of healthy Korean parents. Hypoparathyroidism was first noticed due to seizure. A multicystic left dysplastic kidney and vesicoureteral reflux were detected by ultrasound after birth. Auditory brainstem response (ABR) testing revealed that the patient had moderate sensorineural deafness, with hearing losses of 80 dB at the mid and higher frequencies for both ears. Echocardiography finding revealed secundum atrial septal deftect. Based on biochemical results and clinical findings, a presumptive diagnosis of HDR syndrome was made. GATA3 mutation analysis identified a heterozygous deletion, c.153del (p.Phe51Leufs*144) in exon 1 causing a frameshift mutation, which is a novel de novo mutation. Therefore, we suggest that HDR syndrome should be considered in the differential diagnosis in symptomatic or asymptomatic patients with hypoparathyroidism, and that renal ultrasound or ABR testing be performed to prevent a missed diagnosis. This is the first report on Korean patient with confirmed HDR syndrome with novel mutation.

[Barakat syndrome a report of two cases]

Barakatsyndrome or HDR syndrome [Hypoparathyroidism, sensorineural deafness and renal disease] is an inherited condition. It's a very rare disease. Patients may present with tetany or convulsions due to hypocalcemia at any age. Deafness is usually bilateral and may range from mild to profound impairment. Renal disease has several manifestations. We report the cases of a girl [Ferdaous] and a boy [Taha] which are respectively of 16 years old and 6 years old. The girl only was born of intermarriage. Her brother and sister were treated for hypoparathyroidism. Both of our patients had sensorineural deafness and a nephropathy: a nephrotic syndrome in Ferdaous's case and a proteinury in Taha's case. The girl was treated for hypoparathyroidism since she was 12 while the boy was admitted in emergency for tonico-clonic seizures, reported to a profound hypocalcaemia. Hypoparathyroidism was confirmed by a very low parathormone rate. The endocrinal and cerebral radiological investigations were normal. By this case report, the authors remember the Barakat syndrome: its clinical and biological features, and its different possible progressions. The mode of inheritance is believed to be autosomal dominant. Mutations in the GATA3 gene, mapped to chromosome 10p [gene map locus 10p15, 10p15.1-p14], have been identified in several families with Barakat syndrome. Possibilities of antenatal diagnostic are offered to theses families