We reported a delayed diagnosised Chinese JATD case with mild skeletal phenotype, and presented with renal insufficiency as the initial symptom of disease onset. Novel bilateral c.2789C>T (p.S930L) mutations in WDR60 gene were identified. Our report will help to improve our awareness and diagnosibility for this disease in China.

Gitelman syndrome (GS) is a kind 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 exonic variants disrupt normal pre-mRNA splicing, has been related to a variety of diseases. The purpose of this study was to identify the effect of previously presumed missense SLC12A3 variants on pre-mRNA splicing using bioinformatics tools and minigenes. The results 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. It 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.

Primary distal renal tubular acidosis (dRTA) is a rare tubular disease associated with variants in SLC4A1, ATP6V0A4, ATP6V1B1, FOXⅠ1 or WDR72 genes. Currently, there is growing evidence that all types of exonic variants can alter splicing regulatory elements, affecting the pre-mRNA splicing process. This study was to determine the consequences of variants associated with dRTA on pre-mRNA splicing combined with predictive bioinformatics tools and minigene assay. As a result, among the 15 candidate variants, 8 variants distributed in SLC4A1 (c.1765C>T, p.Arg589Cys), ATP6V1B1( c.368G>T, p.Gly123Val; c.370C>T, p.Arg124Trp; c.484G>T, p.Glu162* and c.1102G>A, p.Glu368Lys) and ATP6V0A4 genes (c.322C>T, p.Gln108*; c.1571C>T, p.Pro524Leu and c.1572G>A, p.Pro524Pro) were identified to result in whole or part of exon skipping by either disruption of ESEs and generation of ESSs, or interference with the recognition of the classic splicing site, or both. To our knowledge, this is the first study on pre-mRNA splicing of exonic variants in the dRTA-related genes. These results highlight the importance of assessing the effects of exonic variants at the mRNA level and suggest that minigene analysis is an effective tool for evaluating the effects of splicing on variants in vitro