Novel < b > < i > de novo < /i > < /b > < b > < i > AVPR2 < /i > < /b > Variant in a Patient with Congenital Nephrogenic Diabetes Insipidus

In this study, a Swedish male with no family history was diagnosed with CNDI at 6 months of age during an episode of gastroenteritis. We analyzed the coding regions ofAVPR2 by PCR and direct DNA sequencing and identified an 80-bp duplication in exon 2 (GenBank NM_000054.4; c.800_879dup) in the proband. This variant leads to a frameshift and introduces a stop codon four codons downstream (p.Ala294Profs*4). The variant gene product either succumbs to nonsense-mediated decay or is translated to a truncated nonfunctional vasopressin V2 receptor. This variant was absent in four unaffected family members, including his parents, as well as in 100 alleles from healthy controls, and is thus considered a novelde novo disease-causing variant. Identification of the disease-causing variant facilitated precise diagnosis of CNDI in the proband. Furthermore, it allows future genetic counseling in the family. This case study highlights the importance of genetic testing in sporadic infant cases with CNDI that can occur due tode novo variants inAVPR2 or several generations of female transmission of the disease-causing variant.Case Rep Nephrol Dial 2017;7:130 –137
Source: Case Reports in Nephrology and Dialysis - Category: Urology & Nephrology Source Type: research