Abstract:

Objective To report the efficacy and safety of lamotrigine in the treatment of one case of Becker myotonia congenita. Methods and Results A 17-year-old male had muscle stiffness in the limbs as the first symptom, which could be alleviated after repeated exercise. The creatine kinase (CK) level was normal. Genetic testing showed there were two missense mutations c.1205C > T (p.Ala402Val) and c.896T > C (p.Val299Ala) located in exon 11 and 8 of CLCN1 gene respectively in the proband. The missense mutation c.1205C > T (p.Ala402Val) in exon 11 was found out in his mother and c.896T > C (p.Val299Ala) located in exon 8 was found out in his father. The latter, exon 8 c.896T > C of CLCN1 gene has not been reported. The proband was clearly diagnosed as Becker myotonia congenita, and his family was diagnosed as Becker myotonia congenita pedigree. After 5 years' treatment with lamotrigine, the symptom of myotonia was significantly improved and no adverse reactions was observed. Conclusions The missense mutation in exon 8 c.896T > C in this patient further expanded the CLCN1 gene mutation spectrum. Lamotrigine is effective in treating Becker myotonia congenita, providing a new idea for the treatment of myotonia congenita.

Key words: Myotonia congenita, Triazines, Genes, Mutation, missense, Pedigree

摘要：

目的 报道拉莫三嗪治疗 1 例 Becker 型先天性肌强直患者的疗效及安全性。方法与结果 17 岁男性患者，以四肢肌肉僵硬为首发症状，反复运动后症状减轻，血清肌酸激酶水平正常，基因检测提示存在 CLCN1 基因外显子 11 c.1205C > T（p.Ala402Val）及 CLCN1 基因外显子 8 c.896T > C（p.Val299Ala）错义突变，确诊为 Becker 型先天性肌强直；其母为 CLCN1 基因外显子 11 c.1205C > T（p.Ala402Val）、其父为 CLCN1 基因外显子 8 c.896T > C（p.Val299Ala）错义突变，确诊为 Becker 型先天性肌强直家系，其中 CLCN1 基因外显子 8 c.896T > C 突变尚无报道。经拉莫三嗪连续治疗 5 年后肌强直症状长期缓解，且无任何药物不良反应。结论 该例 CLCN1基因外显子8 c.896T > C 错义突变进一步扩展了CLCN1基因突变谱。拉莫三嗪治疗效果良好，为 Becker型先天性肌强直的治疗提供了新的思路。

关键词: 先天性肌强直, 三嗪类, 基因, 突变, 误义, 系谱