title: A family of hypokalemic periodic paralysis with CACNA1S gene mutation showing incomplete penetrance in women.
abstract: Familial hypokalemic periodic paralysis is an autosomal dominant genetic muscle disease characterized by periodic attacks of muscle weakness associated with a decrease in serum potassium. There are two major missense mutation sites in the calcium channel alpha1 subunit (CACNA1S) gene in these patients. We recently encountered a 13-year-old Japanese boy who had collapsed following exercise and was found to have a low serum potassium level. Clinical and genetic studies including exploration of his family tree proved that he and his maternal relatives had the disease with the missense mutation, Arg528His (CGC --> CAC). However, his mother and grandmother had no symptoms of the disease, indicating reduced penetrance in female carriers. Sexual difference in the penetrance of this disease and the association between the clinical symptoms and the types of genetic defects are discussed.
authors.affiliation: Department of Internal Medicine, Hyogo Prefectural Nishinomiya Hospital, Nishinomiya.
authors.forename: Shuji
authors.initials: S
authors.lastname: Kawamura
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Ikeda
authors.forename: Koji
authors.initials: K
authors.lastname: Tomita
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Watanabe
authors.forename: Kouichi
authors.initials: K
authors.lastname: Seki
mesh_terms: D001120:Arginine / Q000235:genetics; D015220:Calcium Channels / Q000235:genetics; D020908:Calcium Channels, R-Type; D027682:Cation Transport Proteins / Q000235:genetics; D015444:Exercise / Q000502:physiology; D006632:Histamine / Q000235:genetics; D006801:Humans; D020514:Hypokalemic Periodic Paralysis / Q000235:genetics* / Q000378:metabolism; D008297:Male; D020125:Mutation, Missense; D010375:Pedigree; D019683:Penetrance; D011188:Potassium / Q000097:blood / Q000652:urine
chemical_list: C423009:CACNA1E protein, human; D015220:Calcium Channels; D020908:Calcium Channels, R-Type; D027682:Cation Transport Proteins; D006632:Histamine; D001120:Arginine; D011188:Potassium