ESPN 51th Annual Meeting

ESPN 2018


 
X-LINKED NEPHROGENIC DIABETES INSIPIDUS DIAGNOSED LATELY IN 7 YEAR-OLD BOY
BURCU BOZKAYA YÜCEL 1 MEHTAP EZEL ÇELAKIL 1 AYŞE BURCUM BÜYÜKUYSAL 1 KENAN BEK 1

1- KOCAELI UNIVERSITY FACULTY OF MEDICINE DEPARTMENT OF PEDIATRIC NEPHROLOGY
 
Introduction:

 Kidneys can’t concentrate urine secondary to antidiuretic hormone(ADH)-resistance in nephrogenic diabetes insipidus (NDI). The x-linked mutations of the arginine vasopressin V2 receptor (AVPR2) gene are the most common cause of hereditary NDI. Clinical symptoms, usually severe in affected males, include polyuria, polydipsia, bouts of dehydration and enuresis. Mild forms may be seen in females due to skewed inactivation of X chromosome. 

Material and methods:

CASE

Results:

 A 7-year-old boy was admitted to the emergency department with diarrhea, vomiting and fever. His medical history included compulsive water drinking since infancy. His height and weight were both below 2 SD. Physical examination and laboratory tests were nonrevealing except moderate dehydration. His urine density was 1005 with Na concentration of 8,9 mOsm/L. Initial Urine and plasma osmolalities were 49  and 290 mOsm/kg. Serum ADH level was normal (21,96 pg/ml). Water deprivation and lack of response to DDVAP confirmed the diagnosis of NDI.  Family history of maternal grandfather with similar complaints strongly suggested the diagnosis of X-linked dominant NDI and the definitive diagnosis was confirmed by genetic analysis (AVPR2 gene NM_000054,4 c.541C>T homozygous). Indomethacin and aldactazide induced prompt clinical and laboratory improvement.

Conclusions:

 Delay in the diagnosis of X linked NDI may end up with growth and mental retardation. Therefore in  male infants with typical findings and positive family history it should always be considered in differential diagnosis and genetic confirmation should be done.