A Case of Congenital Nephrogenic Diabetes Insipidus Confirmed by Gene Analysis / 소아과

ABSTRACT

Nephrogenic diabetes insipidus (NDI) is a disorder in which the secretion of antidiuretic hormone is normal, but the response of the renal collecting tubules to vasopressin is impaired. Compared with acquired NDI (a-NDI), which is secondary to chronic bilateral incomplete urinary tract obstruction with hydronephrosis, congenital NDI (c-NDI) is a very rare heritable disorder that usually follows the X- linked recessive pattern. Clinical symptoms of c-NDI can be non specific, and often the disease ultimately results in failure to thrive, or mental retardation. Recently, the diagnosis can be confirmed by direct sequencing analysis of the peripheral blood specimens. The long-term results of treatment for c-NDI are not satisfactory. Reports on the follow up of c-NDI cases are rare and there is no report on the cases treated with combinations of three drugs. We report herein a case of severe c-NDI in an 8 year-old-boy with a severely dysconfigurated urinary tract system. The patient and his mother showed a frameshift mutation on the AVPR2 gene on chromosome Xq28 .847_851delTGCTG (p.C283fsX90). The patient showed normal growth and development by treatment with combinations of hydrochlorothiazide (65 mg/m2), amiloride (0.3 mg/kg/d) and indomethacin (100 mg/m2), yet after five years he needed adjuvant cystostomy to relieve him from the residual symptoms of urgency with polyuria.