Familial periodic paralysis associated with a rare KCNJ5 variant that supposed to have incomplete penetrance

Abstract Background The periodic paralyses are a group of skeletal muscle channelopathies caused by variants in several ion channel genes. Potassium Inwardly Rectifying Channel Subfamily J Member 5 (KCNJ5) encodes the G-protein–activated inwardly rectifying potassium 4 (Kir3.4) and heterozygous KCNJ5 cause familial hyperaldosteronism long QT syndrome (LQTS). Recent studies suggested that also causative for Andersen-Tawil syndrome, which showed paralysis characteristic electrocardiogram features. Clinical report. We found variant c.1159G > C, p.(Gly387Arg) an individual with using exome sequencing. Sanger sequencing revealed this was inherited from his affected mother. same had been previously two cases LQTS or functional analysis might have loss function effect on activity. However, allele frequency c.1159G > C East Asian population public databases ranged 0.21% to 0.25%, indicating possible incomplete penetrance. Conclusions Our patients expand phenotypic spectrum associated variant, though has very low