[Mutation of Thr704Met in SCN 4A causes normoKPP in a Chinese family].

Familial periodic paralysis (PP) is an autosomal dominant disorder characterized by episodic attacks of paralysis with different severity. We recruited a normoKPP family in Hubei China and evaluated genetic variations responsible for the disease. Linkage analysis was performed through microsatellite markers. Markers flanking SCN4A showed linkage evidence in the family. Sequencing of SCN4A exons revealed a substitution C2111T leading to the mutation Thr704Met in all affected family members, and was not observed in either unaffected members of the family or 100 unrelated individuals (controls). This mutation should be responsible for normoKPP in this family.