Analysis of one familial hypokalemic periodic paralysis family with R669H variant of SCN4A gene / 临床神经病学杂志

ABSTRACT

Objective To investigate the clinical and genetic characteristics of a family with hypokalemic periodic paralysis(HOKPP).Methods The clinical data of one HOKPP family were retrospectively analyzed.Results The proband presented with periodic paralysis,limb weakness and decreased serum potassium(1-2 mmol/L).The proband's father and cousin had similar symptoms.A heterozygous missense variant c.2006G＞A(p.R669H)in SCN4A gene was identified in the proband,his father,younger aunt and cousin using gene detection.However,the variant was absent in his elder aunt and younger uncle.Conclusions The family shows irregular dominant inheritance.The severity,frequency and age of onset of male heterozygotes were different,while female heterozygotes had no clinical phenotype.The study first confirms that the R669H variant in SCN4A gene causes complete penetrance in males and carriers in females in Asian populations.