{Reference Type}: Case Reports {Title}: A case of aquaporin 2 R85X mutation in a boy with congenital nephrogenic diabetes insipidus. {Author}: Bircan Z;Karacayir N;Cheong HI; {Journal}: Pediatr Nephrol {Volume}: 23 {Issue}: 4 {Year}: Apr 2008 {Factor}: 3.651 {DOI}: 10.1007/s00467-007-0682-0 {Abstract}: Autosomal recessive nephrogenic diabetes insipidus (ARNDI) is a rare disease usually seen in patients with consanguineous parents. We report on a case of ARNDI in a patient with non-consanguineous parents who presented with recurrent febrile attacks. The differential diagnosis of ARNDI was made by desmopressin infusion test. A homozygous mutation, R85X, was detected in the aquaporin 2 gene (AQP2) of our patient, which has been described only once previously. This case is presented to stress that even male patients with non-consanguineous parents could have ARNDI with a AQP2 gene defect, and the desmopressin infusion test is useful for differential diagnosis.