Periodic paralysis mutation MiRP2-R83H in controls - Interpretations and general recommendation

An R83H point mutation in KCNE3-encoded MiRP2 has been reported to cause 2% of all cases of familial periodic paralysis. The authors found MiRP2-R83H in 3 of 321 control subjects and in 5 unaffected related individuals. Provocation of an unaffected carrier with glucose or KCl did not induce weakness. The authors propose that causality criteria for mutations require exclusion of mutations in n = ln(P)/ ln( 1 = p(1)) ethnically matched control chromosomes ( P = acceptable error probability; p(1) = mutation prevalence in patient chromosomes).