Autosomal dominant familial hypoparathyroidism and sensorineural deafness without renal dysplasia

Objective: A family is described which has a unique combination of autosoma l dominant hypoparathyroidism and sensorineural deafness without renal dysp lasia, Case report: The proband was a male infant aged 1 month with episodes of se izures for 20 days. He was born at 35 weeks' gestation without asphyxia, we ighing 2040 g. His initial calcium, phosphorus and percentage of tubular re absorption of phosphorus were 6.8 mg/dl (normal range 8.5-10.5 mg/dl), 8.9 mg/dl (normal range 5.5-7.4 mg/dl) and 96.8% (normal range 85-95%) respecti vely He had normal values for serum parathyroid hormone (PTH) and 25-hydrox yvitamin D. No abnormalities were found by renal imaging and a routine rena l function study. He shelved a brisk plasma cAMP increase in response to hu man PTH-(1-34) infusion. He had normal karyotype 46, XY, without a microdel etion in chromosome 22q11.2 by an in situ hybridization method. Five family members were affected with hypoparathyroidism with sensorineural deafness with autosomal dominant transmission. The study of calcium-sensing receptor and preproPTH gene showed a normal DNA sequence. Conclusion: The combination of familial hypoparathyroidism with sensorineur al deafness without renal dysplasia is novel and the cause may be distinct from previously reported familial hypoparathyroidism with sensorineural dea fness and renal dysplasia.