Savad Shahram, Ashrafi Mahmoud Reza, Samadaian Niusha, Heidari Morteza, Modarressi Mohammad-Hossein, Zamani Gholamreza, Amidi Saloomeh, Younesi Sarang, Amin Mohammad Mahdi Taheri, Saadati Pourandokht, Ronagh Alireza, Ardakani Hossein Shojaaldini, Eslami Solat, Ghafouri-Fard Soudeh
Genome-Nilou Laboratory, Tehran, Iran.
Pediatric Neurology Division, Children's Medical Center, Pediatrics Center of Excellence, Ataxia Clinic, Tehran University of Medical Sciences, Tehran, Iran.
Sci Rep. 2023 Feb 24;13(1):3202. doi: 10.1038/s41598-023-30449-7.
Spinal muscular atrophy (SMA) is among the most common autosomal recessive disorders with different incidence rates in different ethnic groups. In the current study, we have determined SMN1, SMN2 and NAIP copy numbers in an Iranian population using MLPA assay. Cases were recruited from Genome-Nilou Laboratory, Tehran, Iran and Pars-Genome Laboratory, Karaj, Iran during 2012-2022. All enrolled cases had a homozygous deletion of exon 7 of SMN1. Moreover, except for 11 cases, all other cases had a homozygous deletion of exon 8 of SMN1. Out of 186 patients, 177 (95.16%) patients showed the same copy numbers of exons 7 and 8 of SMN2 gene. In addition, 53 patients (28.49%) showed 2 copies, 71 (38.17%) showed 3 copies and 53 patients (28.49%) showed 4 copies of SMN2 gene exons 7 and 8. The remaining 9 patients showed different copy numbers of exons 7 and 8 of SMN2 gene. The proportions of SMA patients with different numbers of normal NAIP were 0 copy in 73 patients (39.24%), 1 copy in 59 patients (31.72%), 2 copies in 53 patients (28.49%) and 4 copies in one patient (0.5%). These values are different from values reported in other populations. Integration of the data of the SMN1/2 and NAIP genes showed 17 genotypes. Patients with genotype 0-0-3-3-1 (0 copies of SMN1 (E7,8), 3 copies of SMN2 (E7,8) and 1 copy of NAIP (E5)) were the most common genotype in this study. Patients with 0-0-2-2-0 genotype were more likely to have type I SMA. The results of the current study have practical significance, particularly in the genetic counseling of at-risk families.
脊髓性肌萎缩症（SMA）是最常见的常染色体隐性疾病之一，在不同种族群体中的发病率有所不同。在本研究中，我们使用多重连接探针扩增（MLPA）检测法测定了伊朗人群中SMN1、SMN2和NAIP的拷贝数。研究病例于2012年至2022年期间从伊朗德黑兰的Genome-Nilou实验室和卡拉季的Pars-Genome实验室招募。所有纳入的病例均存在SMN1基因第7外显子的纯合缺失。此外，除11例病例外，所有其他病例均存在SMN1基因第8外显子的纯合缺失。在186例患者中，177例（95.16%）患者的SMN2基因第7和第8外显子拷贝数相同。此外，53例患者（28.49%）显示有2个拷贝，71例（38.17%）显示有3个拷贝，53例患者（28.49%）显示有4个拷贝的SMN2基因第7和第8外显子。其余9例患者的SMN2基因第7和第8外显子拷贝数不同。不同正常NAIP数量的SMA患者比例分别为：73例患者（39.24%）为0拷贝，59例患者（31.72%）为1拷贝，53例患者（28.49%）为2拷贝，1例患者（0.5%）为4拷贝。这些数值与其他人群报告的数值不同。SMN1/2和NAIP基因数据整合显示有17种基因型。基因型为0-0-3-3-1（SMN1（E7,8）为0拷贝、SMN2（E7,8）为3拷贝、NAIP（E5）为1拷贝）的患者是本研究中最常见的基因型。基因型为0-0-2-2-0的患者更易患I型SMA。本研究结果具有实际意义，尤其是在对高危家庭的遗传咨询方面。
