强直性肌营养不良1型两家系的临床及遗传特点分析

Clinical and genetic characteristics of two families with myotonic dystrophy type I

目的探讨强直性肌营养不良1型(DM1)家系的临床及遗传特点。方法回顾性收集2021年9月、10月就诊于河南科技大学第一附属医院神经内科的2个DM1家系的临床资料,应用肌电图、肌肉MRI检查明确患者的肌肉病变情况,应用重复引物PCR技术检测患者DMPK基因3’端非编码区CTG重复数。结果2个家系中患者存在临床异质性,主要临床表现为骨骼肌受累症状(肌无力、肌萎缩),体征表现为肢体无力、"斧头脸"、叩击性肌强直和"肌球征"等,全身多系统受累症状表现为心慌、胸闷、白内障、消化道症状、疲劳或嗜睡症状和认知功能损害等。患者肌电图表现为肌强直电位、肌源性损害,肌肉MRI表现为肌肉脂肪化和肌肉萎缩,病变以腓肠肌为主。患者DMPK基因3’端非编码区CTG重复数均超过50次或100次。结论除注意DM1患者的骨骼肌受累症状外,临床医师还应注意患者可伴有心脏、眼睛、呼吸、内分泌及神经系统等全身多系统受累症状。

Objective To investigate the clinical and genetic characteristics of families with myotonic dystrophy type I.Methods Two families with myotonic dystrophy type I admitted to Department of Neurology,First Affiliated Hospital of He'nan University of Science and Technology in September and October 2021 were chosen;their clinical data were retrospectively analyzed.The muscle pathological changes were confirmed by electromyography and muscle MRI.Repeat-primed PCR assay was used to detect the number of CTG repeats in the 3'end non-coding region of DMPK gene.Results Clinical heterogeneity existed among the two families of patients;muscle weakness and muscular atrophy of the skeletal muscle were the main clinical manifestations;limb weakness,axe face,percussion myotonia and myoglobular sign were noted;systemic multi-system symptoms included palpitation and chest tightness,cataracts,gastrointestinal symptoms,fatigue/lethargy,and cognitive impairment.Electromyography showed myotonic potential and myogenic damage.Muscle fatty infiltration and atrophy were noted in muscle MRI,and lesions were predominantly in the gastrocnemius.All patients had abnormal amplification of DMPK gene CTG(number of CTG repeats>50 or 100).Conclusion In addition to skeletal muscle involvement,systemic multi-system involvement such as cardiac,eye,respiratory,endocrine,and nervous system should also be noted by clinicians in patients with myotonic dystrophy type I.