周围髓鞘蛋白22基因重复突变致夏科-马里-图斯病1A亚型的临床和神经电生理特征

Clinical and electrophysiological characteristics of Charcot-Marie-Tooth disease type 1A patients with PMP22 duplication mutation

目的探讨周围髓鞘蛋白22(PMP22)基因重复突变阳性的夏科-马里-图斯病(CMT)lA亚型患者临床和神经电生理改变特点。方法总结21例PMP22基因重复突变阳性的CMTlA患者的临床特点,并分析其神经电生理特征。结果 21例患者中,10例临床特征符合四肢远端萎缩无力的典型CMTl型表现,另外11例呈不典型性,如仅有头晕、合并听力障碍、上肢姿势性震颤、反复发作性肢体无力、伴有小脑性共济失调及癫疒间等。10例患者肌电图出现纤颤电位和(或)正锐波,15例患者运动单位电位时限延长。神经传导存在广泛异常,所有患者被检的运动或感觉神经传导速度存在不同程度的减慢或消失。结论 PMP22重复突变阳性的CMTlA患者具有较高的临床异质性,其电生理特点为肌电图呈神经源性损害,感觉神经病变重于运动神经,下肢受累程度重于上肢,神经电生理检查对CMT1A的诊断很重要。

Objective To investigate the clinical and electrophysiological characteristics in Charcot-Marie- Tooth disease （CMT） type 1A patients with （peripheral myetin protein22, PMP22 ） duplication mutation. Methods Twenty one patients with CMT 1A were retrospectively studied. Routine electromyography （EMG） and nerve conduction had been performed in all patients. The clinical and electrophysiological features were analyzed. Results 10 of 21 patients showed typical presentations including weakness and atrophy in the distal parts of limbs, and 11 atypical cases with special phenotypes including mild dizziness, hearing loss, postural tremor in the upper limbs, recurrent limbs weakness, eerebellar ataxia and epilepsy. EMG detected fibrillation potentials and positive sharp waves in 10 patients and prolonged duration of motor unit potentials in 15 patients respectively. Nerve conduction studies revealed decreased nerve conductive velocity or unelicited potentials in all detected nerves in the patients. Conclusion The CMT 1A patients with positive PMP22 duplication indicate the high clinical variability. The electrophysiological features of these patients are neurogenic lesion, sensory nerves are more susceptible than motor nerve, and the nerve damage in lower limbs is more severe than that in upper limbs, eleetrophysiologieal examination may play a very important role in diagnosis of CMT1A.