甲亢性低血钾型周期性麻痹家系基因突变的初步研究

目的筛查甲亢性低血钾型周期性麻痹家系的钙离子通道α1亚基和电压门控钠离子通道α亚基基因是否存在突变。方法总结甲亢性低血钾型周期性家系Ⅵ代患者的临床特点，并应用酶联免疫测定和测序技术筛查编码钙离子通道α1亚基的528位及1239位精氨酸和钠离子通道α亚基669位及672位精氨酸基因的突变点。结果钠离子通道α亚基基因2012位碱基序列发生错义突变（T→C），671位苯丙氨酸变为丝氨酸，而其他3个已知突变点的碱基序列完全正常。结论华人甲亢性低血钾型周期性麻痹家系患者中存在突变，致使钠离子通道α亚基基因671位苯丙氨酸为丝氨酸替代，该位点国内外未见报道，是一个新的突变位点。

A New SCN4A Mutation in A Chinese Family with Thyotoxic Hypokalemic Periodic Paralysis:Phe671Ser

Objective To observe whether the mutations in the CACNIAA3 and SCN4A genes exist in a Chinese family with thyrotoxic hypokalemic periodic paralysis. Methods In the Chinese family, The nucleic acid sequences coding the amino acid of 528 and 1239 in CACNL1A3, and of 669 and 672 in SCN4A gene were researched with PCR and sequence technology, to confirm whether the mutations exist. Results This family showed typical clinical features of thyrotoxic hypokalemic periodic paralysis. The nucleic acid sequences were normal in CACNL1A3. The T2012C nucleic acid substitution was found in SCN4A gene,resulted in the Phe671Ser substitution. Conclusion The Phe671Ser substitution does exist in the Chinese family and is different from the known mutations in thyrotoxic hypokalemic periodic paralysis. It is a completely new substitution.