Department of Neurology, Gangnam Severance Hospital, Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea.
Yonsei Med J. 2012 Jan;53(1):53-7. doi: 10.3349/ymj.2012.53.1.53.
The association between survivor motor neuron (SMN) gene deletion and spinal muscular atrophy suggests that sporadic amyotrophic lateral sclerosis (sALS) may be related to SMN deletion. We examined the association between the SMN genotype and susceptibility to and severity of sALS.
We genotyped the copy number of SMN1 and SMN2 in 25 patients diagnosed with sporadic ALS and 100 healthy subjects in a Korean population. Onset age and medical research council (MRC) scale were compared among patients according to SMN1 : SMN2 genotypes.
There was a significantly higher incidence of homozygous deletion of SMN2 (SMN1 : SMN2 genotype, 2 : 0) in sALS patients (20%) than in the normal controls (2%) (p<0.001). The onset age for patients with homozygous deletion of SMN2 (2 : 0) was significantly younger (34 ± 15.38 years) than that of patients with 2 : 1, 2 : 2 and 2 : 3 of the SMN1 : SMN2 genotype (59.5 ± 5.09; 52.69 ± 16.46 and 50 ± 0.00 years) (p=0.049). The ratio of patients with an MRC scale above G4- was smaller in the 2 : 0 genotype (40%) than in the 2 : 1, 2 : 2 and 2 : 3 genotypes (83.3%, 100% and 100%) (p=0.02).
The homozygous SMN2 deletion (2 : 0) was statistically more frequent and associated with earlier onset age and lower MRC scale in Korean sALS patients. These suggest that SMN2 deletion may be one of the factors associated with susceptibility to and severity of sALS in a Korean population.
存活运动神经元（SMN）基因缺失与脊髓性肌萎缩症之间的关联表明，散发性肌萎缩侧索硬化症（sALS）可能与 SMN 缺失有关。我们研究了 SMN 基因型与 sALS 的易感性和严重程度之间的关系。
我们对 25 名韩国散发性 ALS 患者和 100 名健康对照者的 SMN1 和 SMN2 基因拷贝数进行了基因分型。根据 SMN1：SMN2 基因型，比较患者的发病年龄和医学研究委员会（MRC）量表。
sALS 患者（20%）杂合性 SMN2 缺失（SMN1：SMN2 基因型，2：0）的发生率明显高于正常对照组（2%）（p<0.001）。SMN2 纯合缺失（2：0）患者的发病年龄明显较年轻（34 ± 15.38 岁），而 SMN1：SMN2 基因型 2：1、2：2 和 2：3 的患者发病年龄分别为 59.5 ± 5.09 岁、52.69 ± 16.46 岁和 50 ± 0.00 岁（p=0.049）。2：0 基因型患者的 MRC 量表评分高于 G4-的比例（40%）明显小于 2：1、2：2 和 2：3 基因型患者（83.3%、100%和 100%）（p=0.02）。
韩国 sALS 患者中，SMN2 纯合缺失（2：0）更频繁，与发病年龄更早和 MRC 量表评分更低相关。这些结果提示 SMN2 缺失可能是韩国人群中 sALS 易感性和严重程度的相关因素之一。
