Minigene splicing assays reveal new insights into exonic variants of the SLC12A3 gene in Gitelman syndrome

BackgroundGitelman syndrome (GS) is a type of salt-losing tubular disease, most of which is caused by SLC12A3 gene variants, and missense variants account for the majority. Recently, the phenomenon of exon skipping, in which variants disrupt normal pre-mRNA splicing, has been related to a variety of diseases. Therefore, we hypothesize that a certain proportion of SLC12A3 variants can result in disease via interfering with the normal splicing process. MethodsWe analyzed 342 previously presumed SLC12A3 missense variants using bioinformatics programs and identified candidate variants that may alter the splicing of pre-mRNA through minigene assays. ResultsOur study revealed that, among ten candidate variants, six variants (c.602G>A, c.602G>T, c.1667C>T, c.1925G>A, c.2548G>C, and c.2549G>C) led to complete or incomplete exon skipping by affecting exonic splicing regulatory elements and/or disturbing canonical splice sites. ConclusionIt is worth mentioning that this is the largest study on pre-mRNA splicing of SLC12A3 exonic variants. In addition, our study emphasizes the importance of detecting splicing function at the mRNA level in GS and indicates that minigene analysis is a valuable tool for splicing functional assays of variants in vitro.

Automated summary

This study revealed that six SLC12A3 variants can cause exon skipping and contribute to the development of Gitelman syndrome. The findings highlight the importance of detecting splicing function at the mRNA level and suggest that minigene analysis is a valuable tool for studying splicing in vitro.