X-Linked Recessive Form of Nephrogenic Diabetes Insipidus in A 7-Year-Old Boy

• Published in: Balkan journal of medical genetics 2014-12, Vol.17 (2), p.81-85
• Main Authors: Janchevska, A., Tasic, V., Gucev, Z., Krstevska-Konstantinova, M., Cheong, H. I.
• Format: Article
• Language: English
• Subjects: Antidiuretic hormone (ADH); Arginine vasopressin (AVP); Case Report; Nephrogenic diabetes insipidus (NDI); Urine osmolality
• ISSN: 1311-0160; 1311-0160
• DOI: 10.2478/bjmg-2014-0078

Nephrogenic diabetes insipidus (NDI) is caused by the inability of renal collecting duct cells to respond to arginine vasopressin (AVP)/antidiuretic hormone (ADH). We present the case of a 7-year-old boy with a history of excretion of large amounts of dilute urine and polydipsia since infancy. The boy had several vomiting episodes with mild dehydration during the first 3 years of life. There was no evidence of headaches, dizziness or visual problems. He drinks between 2 and 3 L/day and has 24-hour diuresis of 2 liters, now. He has prepubertal appearance with appropriate weight [+0.85 standard deviation score (SDS)] and height (+0.15 SDS) for his age. His intelligence was also normal. The water deprivation test showed low urine osmolality after 8 hours of dehydration. After desmopressin administration, urine osmolality remained low. Serum osmolality was in the normal range for sex and age before and after desmopressin administration. This indicated a nephrogenic form of diabetes insipidus. Molecular analyses revealed a P286L [p.Pro(CCC)286Leu(CTC)] mutation in the AVPR2 gene, that was inherited from his mother. This patient is the first case with genetically confirmed X-linked inherited form of NDI in the Republic of Macedonia. Molecular analysis confirmed the clinical diagnosis and enabled genetic advice for this family.