ESPN 51th Annual Meeting

ESPN 2018


 
Nephrogenic diabetes insipidus – affecting three males in two generations
STROESCU RAMONA 1 GAFENCU MIHAI 1 FARKAS FLAVIA 2 CHIRITA-EMANDI ADELA 1 ISAC RALUCA 1 MARGINEAN OTILIA 1 DOROS GABRIELA 1

1- "V. BABES" UNIVERSITY OF MEDICINE AND PHARMACY
2- "LOUIS TURCANU" EMERGENCY HOSPITAL FOR CHILDREN
 
Introduction:

 Nephrogenic diabetes insipidus (NDI) is a heterogeneous rare autosomal dominant or X-linked disease. We aim to present a family with nephrogenic diabetes affecting three males in two generations.

Material and methods:

 We report two boys with NDI, a 4 months old boy, admitted for failure to thrive, vomiting and fever, and his 10 years old uncle(bother of the mother), admitted at the same time for excessive fluid intake(11 liters/day). Family history revealed another brother of the mother, who died at age 2 years, due to severe hypernatremic dehydration. 

Results:

 Clinical and lab-work evaluation in the infant showed polyuria 7.8ml/kg/h, plasma hyperosmolarity, hypernatremic hyperchloremic alkalosis, extremely low urine density(1002), elevated ADH, while the uncle had marked polyuria, low urine density and high ADH, suggestive for nephrogenic diabetes insipidus. Treatment with hydrochlorothiazide was initiated (2mg/kg/body) in the infant, leading to decreased urine output (2.85ml/kg/h); however severe consecutive alkalosis and hypokalemia occurred. Aldosterone antagonist(spironolactone) was added, with good response. The uncle received hydrochlorothiazide and fluid intake reduced to 3-4 l/day. Because of the family history, X linked transmission was considered and we performed sequencing of AVPR2 gene. Analysis showed hemizygous likely pathogenic variant c.335G>A p.(Cys112Tyr) in the 2 boys and carrier status of the mother. We note the phenotypic heterogeneity within the same family, one child deceased at age 2 years, one survived well into age 10 years without treatment and another 4 month infant that could have died without specific treatment. 

Conclusions:

 In infants, treatment is particularly difficult. It aims to avoid episodes of dehydration and obtain a normal growth curve.