Haghiri Rosa, Mashayekhi Farhad, Bidabadi Elham, Salehi Zivar
Department of Biology, Faculty of Sciences, University of Guilan, Rasht, Iran.
Department of Biology, Faculty of Sciences, University of Guilan, Rasht, Iran,
Acta Neurobiol Exp (Wars). 2016;76(4):318-323. doi: 10.21307/ane-2017-030.
Autism is characterized by impairment in reciprocal communication and speech, repetitive behaviors, and social communication. The genetic and environmental factors play roles in the pathogenesis of autism. It was recently shown that the genes involved in the folate/homocysteine pathway may be risk factors for autistic children. One of the genes that may be the risk factor for autism is Methionine synthase (MTR). MTR is responsible for the regeneration of methionine from homocysteine. The aim of this study was to analyze the association of MTR A2756G gene polymorphism (rs1805087) and the risk of autism in a population in northern Iran. The prevalence of MTR A2756G polymorphism was determined in 108 children with autism and 130 controls in northern Iran. Genotypes and allele frequencies were determined in patients and controls by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The prevalence of genotype frequencies of AA, AG and GG in autistic children were 57.41%, 22.22% and 20.37%, respectively, while in controls were 61.54%, 32.31% and 6.15%, respectively. There was significant difference between the MTR polymorphism distribution in control and patient groups. The prevalence of allele frequencies of A and G in autistic children were 0.69 and 0.31, respectively and in controls were 0.78 and 0.22, respectively (P=0.03). The MTR G allele conferred a 1.6-fold increased risk to autism relative to the A allele (95% CI=1.06-2.41, P=0.02). The present study suggests that the G allele of MTR A2756G polymorphism is associated with an increased risk of autism.
自闭症的特征是双向沟通和言语受损、重复行为以及社交沟通障碍。遗传和环境因素在自闭症的发病机制中起作用。最近有研究表明，参与叶酸/同型半胱氨酸代谢途径的基因可能是自闭症儿童的危险因素。其中一个可能是自闭症危险因素的基因是甲硫氨酸合成酶（MTR）。MTR负责将同型半胱氨酸再生为甲硫氨酸。本研究的目的是分析伊朗北部人群中MTR A2756G基因多态性（rs1805087）与自闭症风险的关联。在伊朗北部的108名自闭症儿童和130名对照中确定了MTR A2756G多态性的患病率。通过聚合酶链反应-限制性片段长度多态性（PCR-RFLP）确定患者和对照的基因型和等位基因频率。自闭症儿童中AA、AG和GG基因型频率的患病率分别为57.41%、22.22%和20.37%，而对照中分别为61.54%、32.31%和6.15%。对照组和患者组的MTR多态性分布存在显著差异。自闭症儿童中A和G等位基因频率的患病率分别为0.69和0.31，对照中分别为0.78和0.22（P=0.03）。相对于A等位基因，MTR G等位基因使自闭症风险增加1.6倍（95%CI=1.06-2.41，P=0.02）。本研究表明，MTR A2756G多态性的G等位基因与自闭症风险增加有关。
