Biomedical Genomics and Oncogenetics Research Laboratory, Faculty of Sciences and Techniques of Tangier, University Abdelmalek Essaadi, Tangier, Morocco.
Hemoglobin. 2020 May;44(3):190-194. doi: 10.1080/03630269.2020.1772284. Epub 2020 Jun 8.
Sickle cell disease is one of the most common severe monogenic disorders in the world. The -158 I polymorphism (C>T) of the γ-globin gene promoter is known to be associated with increased expression of the γ-globin gene, thus, higher production of Hb F and lesser clinical severity. This study aims to determine the frequency of the I polymorphism and its association with Hb F levels as a modulating factor of sickle cell disease severity in north Moroccan patients. Three hundred and eight subjects carrying the sickle cell mutation and 160 healthy individuals were recruited at the regional hospital of Larache, Morocco. The complete blood count and the Hb F levels were analyzed. The I polymorphism was determined by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique and statistical analysis were done using the Statistical Package for Social Sciences software version 20. Our results estimated the allelic frequency of the I polymorphism in our population at 15.8%. Out of 468 samples, 7.6% were homozygous [+/+] and 16.4% were heterozygous [+/-] for the I polymorphism. This polymorphism was revealed at 20.6% in SS patients, 24.2% in AS carriers, 28.6% in Hb S (: c.20A>T)/β-thalassemia (β-thal) patients and 22.5% in AA subjects. The north Moroccan sickle cell disease patients have shown a low frequency of the I polymorphism. This was later found to be associated with high Hb F levels and mild clinical severity.
镰状细胞病是世界上最常见的严重单基因疾病之一。γ-珠蛋白基因启动子的-158 I 多态性（C>T）已知与 γ-珠蛋白基因表达增加有关，从而导致 Hb F 产量更高，临床严重程度更低。本研究旨在确定 I 多态性的频率及其与 Hb F 水平的关联，作为镰状细胞病严重程度的调节因子。在摩洛哥拉腊什地区医院招募了 308 名携带镰状细胞突变的患者和 160 名健康个体。分析了全血细胞计数和 Hb F 水平。通过聚合酶链反应-限制性片段长度多态性（PCR-RFLP）技术确定 I 多态性，使用社会科学统计软件包版本 20 进行统计分析。我们的结果估计了我们人群中 I 多态性的等位基因频率为 15.8%。在 468 个样本中，7.6%为 I 多态性纯合子[+/+]，16.4%为杂合子[+/-]。该多态性在 SS 患者中占 20.6%，AS 携带者占 24.2%，Hb S（: c.20A>T）/β-地中海贫血（β-地中海贫血）患者占 28.6%，AA 受试者占 22.5%。摩洛哥北部的镰状细胞病患者表现出 I 多态性的低频率。后来发现这与 Hb F 水平高和临床严重程度低有关。
