原发性低钾型周期性麻痹患者的基因及影像学研究  

The genetic and skeletal muscle imaging characteristics of hypokalaemic periodic paralysis patients

作　　者：贾白雪 杨旗[2] 王涵[1] 郭秀海[1] 

机构地区：[1]首都医科大学宣武医院神经内科,100053 [2]首都医科大学宣武医院影像科,100053

出　　处：《中国神经免疫学和神经病学杂志》2014年第1期36-40,共5页Chinese Journal of Neuroimmunology and Neurology

基　　金：北京市"215"高层次卫生技术人才培养计划资助项目(2011-3-091)

摘　　要：目的研究中国原发性低钾型周期性麻痹(hypokalaemic periodic paralysis,HypoPP)患者的基因及影像学特征。方法收集40例原发性HypoPP患者,包括散发性(sporadic periodic paralysis,SPP)33例和家族性(familial periodic paralysis,FPP)7例,同时选取10例年龄匹配的健康对照者。采用PCR及直接测序法对所有患者CACNA1S及SCN4A基因的编码S4片段的外显子进行突变筛查。对20例HypoPP患者(16例SPP、4例FPP)及10例健康对照者进行双小腿肌肉MRI检查,其中1例SPP患者在补钾及改变生活方式3年后进行复查。总结HypoPP患者基因及下肢骨骼肌影像学表现特点。结果分别在1例SPP患者和1个FPP家系中筛查到CACNA1S基因上的R1239H及R900S突变,余患者均未在基因筛查中发现突变。患者MRI脂肪抑制T2WI像上均存在不同程度的高信号,与健康对照组有统计学差异(P<0.01)。小腿不同肌肉受累程度存在差异(P<0.01),最易受累的肌肉依次为比目鱼肌、腓肠肌外侧头、腓肠肌内侧头。患者治疗好转后进行复查,脂肪抑制T2WI异常信号显著减轻和局限。结论大多数中国HypoPP患者不存在CACNA1S和SCN4A基因上高加索人种的已知突变。其小腿肌肉在MRI脂肪抑制T2WI上信号明显高于健康人,肌肉的受累具有选择性,负重的大块肌肉更容易受累。Objective To detect the genetic characteristics of Chinese hypokalaemic periodic paralysis （HypoPP） patients and evaluate their skeletal muscle abnormalities with Magnetic Resonance Imaging （MRI）.Methods Forty Chinese HypoPP patients were identified including 33 sporadic periodic paralysis （SPP） and 7 familial periodic paralysis （FPP） patients coming from different families.Thyroid function,renal function,and urinary test were routinely tested to exclude other causes for HPP.Ten healthy volunteers were also enrolled.Genetic analysis of whole S4 segments in CACNA1S and SCN4A was performed in all the patients by polymerase chain reaction and direct sequencing.Leg muscle of 16 SPP patients,4 FPP patients and 10 healthy controls was examined by a 3.0-T MR system.The MRI examination was repeated in one SPP patient after regular oral potassium citrate treatment for 3 years.The characteristics of the genotype and MR imaging were analyzed.Results Only one SPP patient harboured a mutation in CACNA1S （R1239H） and one FPP patient coming from a four-generation family with 9 patients had the R900S mutation in CACNA1S.None of the other patients had mutation in the screened S4 segments of CACNA1S and SCN4A genes.The MRI of all the examined patients revealed higher signal intensity to different degrees in T2-weighted images with fat suppression （T2W-FS）,which was significantly more common than that of the volunteers.Soleus muscle and gastrocnemius muscle were most commonly involved.The signal alterations of MRI were partially improved after treatment in an SPP patient.Conclusions Most Chinese HypoPP patients do not have known mutations in CACNA1S and SCN4A,but muscle damage do exists.The muscle abnormality is relatively selective and partially reversible.

关 键 词：低钾性周期性麻痹 突变 磁共振成像 

分 类 号：R746.3[医药卫生—神经病学与精神病学]