The entire coding regions and flanking intronic sequences of the AVPR2 gene were amplified from genomic DNA using polymerase chain reaction (PCR).
Three-dimensional protein structures for wild-type and mutant AVPR2 proteins, comparing amino acid sequence properties and predictions of binding sites of these proteins, were obtained with computational tools including Swiss-Model and UCSF Chimera 1.10.2 servers.
To predict the functional effect of mutation on the resulting mutant AVPR2, it was also analysed using Phenotyping Polymorphism v2 (PolyPhen-2) software.
All of the coding regions for the AVPR2 gene of the proband were screened by DNA sequence analysis.
Using the Swiss-Model and UCSF Chimera 1.10.2 servers, we found some differences between alpha-helix and beta-sheet structures of wild-type and mutant AVPR2 proteins (Figure 3).
CNDI is a rare disease, most commonly caused by mutations in the AVPR2 in the collecting duct epithelial cells, which is encoded by the AVPR2 gene (Xq28).
Currently, over 250 mutations in the AVPR2 have been described as the cause of NDI .
In conclusion, we report Japanese NDI patients with AVPR2 mutations (p.K100KfsX91, p.W99X, and p.R106C).
Usui (Kyoto Medical Center, Kyoto, Japan) for kindly sequencing AVPR2 in Case 2.
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