Department of prenatal diagnostic center, Shijiazhuang gynaecology and obstertrics Hospital, Key Laboratory of Maternal and Fetal Medicine of Hebei Province, Hebei, Shijiazhuang, P.R. China.
Department of obstetrics and gynecology, Shijiazhuang gynaecology and obstertrics Hospital, Hebei, Shijiazhuang, P.R. China.
Medicine (Baltimore). 2022 Jul 22;101(29):e29591. doi: 10.1097/MD.0000000000029591.
This study aimed to characterize the genetic, pathological, and clinical alterations of 17 patients in China presenting with nondystrophic myotonia (NDM) and to analyze the relationship between genotype and clinical phenotype.
CLCN1 and SCN4A genes in patients with clinical features and muscle pathology indicative of NDM were sequenced. Furthermore, KCNE3 and CACNA1S genes were assessed in patients with wild-type CLCN1 and SCN4A.
Patients may have accompanying atypical myopathy as well as muscle hypertrophy, secondary dystonia, and joint contracture as determined by needle electromyography. All the study participants were administered mexiletine in combination with carbamazepine and showed significant improvements in myotonia symptoms in response to this therapy. CLCN1 gene mutation was detected in 8 cases diagnosed with myotonia congenital using gene screening. The detected mutations included 5 missense, 2 nonsense, 1 deletion, and 2 insertions. Further gene analysis showed 4 mutations in the SCN4A gene in patients diagnosed with paramyotonia congenita.
Myotonia congenita and paramyotonia congenita are the predominant forms of NDM in China. NDM may be best diagnosed using genetic analysis in associated with clinical features.
本研究旨在描述中国 17 名非营养不良性肌强直（NDM）患者的遗传、病理和临床改变，并分析基因型与临床表型之间的关系。
对具有非营养不良性肌强直临床特征和肌肉病理学表现的患者进行 CLCN1 和 SCN4A 基因测序。此外，对 CLCN1 和 SCN4A 基因野生型患者进行 KCNE3 和 CACNA1S 基因评估。
通过针电极肌电图检查，所有患者均伴有非典型肌病、肌肉肥大、继发性肌张力障碍和关节挛缩。所有研究参与者均接受美西律联合卡马西平治疗，肌强直症状均有显著改善。通过基因筛查诊断为先天性肌强直的 8 例患者中检测到 CLCN1 基因突变。检测到的突变包括 5 个错义突变、2 个无义突变、1 个缺失和 2 个插入。进一步的基因分析显示，4 例先天性副肌强直症患者的 SCN4A 基因发生突变。
先天性肌强直和先天性副肌强直是中国 NDM 的主要形式。NDM 的最佳诊断方法是结合临床特征进行基因分析。
