Mutation analysis of AVPR2 and AQP2 gene in Chinese patients with congenital nephrogenic diabetes insipidus

To detect mutations of the aquaporin 2 gene(AQP2) and the arginine vasopressin V2 receptor gene(AVPR2) of Chinese congenital nephrogenic diabetes insipidus, and to establish the foundation for further studying the emergence mechanism of the disease and clinical diagnosis, all the exons and part of introns of AQP2 and AVPR2 genes were amplified with intronic primers, using genomic DNA extracted from three patients with congenital nephrogenic diabetes insipidus and two mothers as template, PCR product was ligated into a T-vector and then sequenced. The result was compared with the database sequence to identify the mutable sites via a BLAST search, the incidence of every mutation was analyzed, and the putative transcription factor binding sites that maybe disturbed were analyzed by MAPPER. Mutation g. 1394A > G in exon 3 of AVPR2 was detected in all the subjects, g.861C > T(S167L) in exon 2 of AVPR2 and IVS1+3G > A in intron of AQP2 were detected, respectively, in two patients, and c.836A9 > C in 3' untranslated region of AQP2 was detected in two patients and one mother. Four mutations were identified. g.1394A > G of AVPR2 and c.836A > C of AQP2 have high incidence in patients with nephrogenic diabetes insipidus. Detection on the two sites may become auxiliary diagnosis index of congenital nephrogenic diabetes insipidus.