Neurology Unit, Ospedale A. Manzoni, ASST Lecco, Via Dell'Eremo 9-11, 23900, Lecco, Italy.
Neurology Unit, Ospedale Maggiore di Lodi, ASST Lodi, Largo Donatori del Sangue 1, 26900, Lodi, Italy.
Neurol Sci. 2021 Dec;42(12):5359-5363. doi: 10.1007/s10072-021-05537-z. Epub 2021 Aug 11.
Mutations of the skeletal muscle sodium channel gene SCN4A are associated with several neuromuscular disorders including hyper/hypokaliemic periodic paralysis, paramyotonia congenita and sodium channel myotonia. These disorders are distinguished from dystrophic myotonias by the absence of progressive weakness and extramuscular systemic involvement.
We present an Italian family with 2 subjects carrying a p.Asn1180Ile mutation in SCN4A gene showing a peculiar clinical picture characterized by the association of myopathic features and myotonia.
The clinical, electromyographic and histological findings of these patients are reported. The possible pathogenicity of the mutation was tested by three different software, all giving positive results.
This is the first report of a dominant, heterozygous mutation in SCN4A causing a complex phenotype of non-congenital myopathy and myotonic syndrome. We suggest that, in patients with myotonia and myopathy not related to dystrophic myotonias, the sequence analysis of SCN4A gene should be performed.
骨骼肌钠离子通道基因 SCN4A 的突变与多种神经肌肉疾病有关，包括高/低钾周期性麻痹、先天性副肌强直和钠离子通道肌强直。这些疾病与肌营养不良性肌强直的区别在于没有进行性无力和肌肉外系统受累。
我们介绍了一个意大利家系，其中 2 名患者携带 SCN4A 基因中的 p.Asn1180Ile 突变，表现出一种特殊的临床特征，其特点是肌病特征和肌强直的联合存在。
报告了这些患者的临床、肌电图和组织学发现。通过三种不同的软件对突变的可能致病性进行了测试，均得出阳性结果。
这是 SCN4A 中导致非先天性肌病和肌强直综合征的复杂表型的显性、杂合突变的首次报道。我们建议，在没有与肌营养不良性肌强直相关的肌强直和肌病患者中，应进行 SCN4A 基因的序列分析。
