Clinical exome analysis was performed for late-onset Gitelman syndrome, which incidentally revealed a germline heterozygous mutation in CAPN3 (CAPN3(NM_000070.3):c.1466G > A; p.(Arg489Gln)) responsible for autosomal dominant limb girdle muscular dystrophy. This evidence concerns the gene CAPN3 and muscular dystrophy, limb-girdle, autosomal dominant.