Author/Editor     Kotnik, Primož; Battelino, Tadej; Debeljak, Maruša; Podkrajšek-Trebušak, Katarina; Waldhauser, F; Frokiaer, J; Nielsen, S; Kržišnik, Ciril
Title     Correlation between AVPR2 mutations and urinary AQP2 excretion in patients with nephrogenic diabetes insipidus
Type     članek
Source     J Pediatr Endocrinol Metab
Vol. and No.     Letnik 20, št. 4
Publication year     2007
Volume     str. 483-9
Language     eng
Abstract     Activation of the V2 receptor by arginine vasopressin (AVP) results in trafficking of the water channel AQP2 to the luminal plasma membrane and a small amount into the urine. Mutations in the A VPR2 gene, encoding the AVP V2 receptor, result in congenital nephrogenic diabetes insipidus (CNDI). To determine a correlation between A VPR2 mutations and urinary AQP2 excretion, immunobloting was used to detect AQP2 in the urine of patients with CNDI before and after a dehydration test. The patients' genotype was determined using PCR amplification and direct sequencing of the complete A VPR2 gene. Urinary AQP2 excretion was absent in patients with severely debilitating mutations, a novel total deletion of the A VPR2 gene, and a novel nonsense mutation W296X. However, it was detected in siblings with a V88M missense mutation. Urinary AQP2 excretion correlated well with other tested phenotype markers. Urinary AQP2 excretion could be used to evaluate the remaining in vivo integrity of the AVP-V2 receptor-AQP2 cascade in patients with CNDI.
Descriptors     MUTATION
ADULT
CHILD, PRESCHOOL
DEHYDRATION
DIABETES INSIPIDUS, NEPHROGENIC
GENOTYPE
PHENOTYPE
RECEPTORS, VASOPRESSIN