Genetic analysis of SLC12A3 gene and diagnostic process in patients with Gitelman syndrome

As the most frequent inherited tubulopathy, Gitelman syndrome (GS), has an incidence that has increased worldwide. The distribution of SLC12A3 gene mutation hotspots deserves exploration. In addition, GS is not a benign syndrome; however, the diagnostic process of GS has not yet been completely detailed.We report two cases of GS pedigrees involving two previously unreported mutations, c. 676G>A, p. A226T and c. 421G>A, p. G141R, in the SLC12A3 gene and reviewed relevant literature. We searched the literature for nucleotide of SLC12A3 in PubMed and other databases as of April 20, 2020.A total of 1,794 detected mutated alleles in 939 patients worldwide were included in this study. Splicing mutations and p. Gly741Arg were mutation hotspots in a European population. P. Leu858His and p. Thr60Met were mutation hotspots in an Asian population. P. Leu858His and p. Thr180Lys were considered mutation hotspots in the Japanese population, while p. Thr60Met and p. Asp486Asn were considered mutation hotspots in the Chinese population.Our results identified two novel mutation sites (c. 676G>A, p. A226T and c. 421G>A, p. G141R), if their pathogenicity was determined this could contribute to the enrichment of database resources on GS. Our study has compiled the most comprehensive SLC12A3 gene mutation database in the world thus far to reveal that different regions have different mutation hotspots in SLC12A3. Moreover, the establishment of a diagnostic process for GS has important implications for confirmed cases.