中文摘要：

家族性周期性麻痹（periodic paralysis，PP）是以反复发作骨骼肌迟缓性瘫痪为特征的一组疾病。我们对一个来自湖北省的正常血钾周期性麻痹家系进行致病基因突变检测。应用微卫星标记对该家系进行连锁分析，证实致病基因可能同SCN 4A连锁。对SCN 4A基因全部外显子测序，发现患者在一个致病突变热点存在碱基替换C2111T。该突变导致编码氨基酸改变Thr704Met，经单链构象多态性分析证明该突变只存在于该家系患者，不存在于家系中健康人和100名无亲缘关系对照中，Thr704Met是该家系的致病突变。

英文摘要：

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 SCN 4A 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.