Yadav Upendra, Kumar Pradeep, Rai Vandana
Human Molecular Genetics Laboratory, Department of Biotechnology, VBS Purvanchal University, Jaunpur, 222003 India.
Indian J Clin Biochem. 2021 Jan;36(1):23-32. doi: 10.1007/s12291-019-00862-9. Epub 2019 Nov 30.
Methionine synthase reductase (MTRR) is an important enzyme of the folate/homocysteine pathway. It is responsible for regulation of methionine enzyme by reductive methylation. A common variant A66G is reported in the FMN-binding domain of the gene, which leads to substitution of isoleucine by methionine (I22M) in MTRR enzyme with reduced activity. Reduced catalytic activity of enzyme leads to high homocysteine concentration in blood and increases risk for numerous diseases. The frequency of A66G polymorphism varies in different ethnic groups. The present study has been designed to evaluate the frequency of A66G gene polymorphism in the Eastern UP population by PCR-RFLP method. Along with this we also performed a meta-analysis to evaluate the global prevalence of this polymorphism. Databases were screened to identified the eligible studies. The prevalence of the G allele and GG genotype was determined by the use of prevalence proportion with 95% CI. Open meta-analyst software was used for the meta-analysis. Total 1000 blood samples were analyzed, the frequencies of A and G alleles were 0.35 and 0.65 respectively. Meta-analysis results revealed that the prevalence of G allele and GG genotype were 49.4% (95% CI 40.6-58.1, ≤ 0.001) and 24.3% (95% CI 17.8-30.9, ≤ 0.001) respectively. In sub-group meta-analysis, the lowest frequency of G allele was found in South America (32.7%; 95% CI 14.1-51.3, ≤ 0.001), and highest in Asia (56.4%; 95% CI 39.5-73.3, ≤ 0.001). The results of the meta-analysis showed that the Asian population has the highest frequency of G allele and highest frequency of the GG genotype was found in the European population.
甲硫氨酸合成酶还原酶（MTRR）是叶酸/同型半胱氨酸途径中的一种重要酶。它通过还原甲基化作用负责调节甲硫氨酸酶。据报道，该基因的黄素单核苷酸（FMN）结合域存在一个常见变异A66G，这导致MTRR酶中的异亮氨酸被甲硫氨酸替代（I22M），活性降低。酶的催化活性降低会导致血液中同型半胱氨酸浓度升高，并增加患多种疾病的风险。A66G多态性的频率在不同种族群体中有所不同。本研究旨在通过聚合酶链反应-限制性片段长度多态性（PCR-RFLP）方法评估印度北方邦东部人群中A66G基因多态性的频率。与此同时，我们还进行了一项荟萃分析，以评估这种多态性的全球流行情况。对数据库进行筛选以确定符合条件的研究。通过使用患病率比例及95%置信区间来确定G等位基因和GG基因型的患病率。使用开放元分析软件进行荟萃分析。共分析了1000份血样，A和G等位基因的频率分别为0.35和0.65。荟萃分析结果显示，G等位基因和GG基因型的患病率分别为49.4%（95%置信区间40.6 - 58.1，P≤0.001）和24.3%（95%置信区间17.8 - 30.9，P≤0.001）。在亚组荟萃分析中，G等位基因频率最低的是南美洲（32.7%；95%置信区间14.1 - 51.3，P≤0.001），最高的是亚洲（56.4%；95%置信区间39.5 - 73.3，P≤0.001）。荟萃分析结果表明，亚洲人群中G等位基因频率最高，而欧洲人群中GG基因型频率最高。
