2型糖尿病患者线粒体ATP6基因变异分析

Variations of mitochondrial gene ATP6 in type 2 diabetes mellitus

目的研究2型糖尿病（T2DM）患者线粒体DNA（mitochondrial DNA，mtDNA）ATP6基因变异与T2DM及其慢性并发症的相关性。方法选取浙江籍汉族人群中临床诊断为T2DM的无血缘关系患者254例，同时收集165名年龄匹配的健康体检者作为健康对照组。提取所有受试者全血基因组DNA，采用PCR扩增线粒体ATP6基因，直接测序后与线粒体基因组剑桥参考序列（rCRS）进行比对。借助生物信息学和统计学方法分析ATP6基因变异。结果所有变异位点的发生率在T2DM组和健康对照组间差异无统计学意义（P〉0．05）。其中有部分位点仅在T2DM组中以低频率出现，多数为错义变异，其改变了线粒体ATP合酶6亚基（ATPase6）跨膜螺旋上高度保守的氨基酸。这些变异位点未见相关报道，同时在合并高血压且为非肥胖患者中检测到，包括G8557A、A8563G、T8594C、C8609T、A8689G、G8998A和G9139A。结论线粒体ATP6基因存在大量变异，多数为多态性位点，但不能排除变异位点A8689G、T8825C、G8920A、G8998A、G9139A提高了T2DM易感性和微效致病性的可能。变异位点G8557A、A8563G、T8594C、C8609T、A8689G、G8998A和G9139A可能与糖尿病、高血压等生物能学疾病的发生有关。

Objective To investigate the correlation between the variations of mitochondrial gene ATP6 and type 2 diabetes mellitus （ T2DM ） and chronic complications. Methods Genomic DNA were extracted from 254 T2DM patients and 165 age-matched controls. After amplification of ATP6 by PCR and direct sequencing, all sequences were compared with the reference sequence （rCRS） to find out the variations. Bioinformatics and statistic method were used to analyze these variations. Results Many variations were detected respectively in T2DM patients and controls, a part of them only appeared in T2DM patients in low frequency, which has not been reported previously. Most of these variations are located in the third and forth transmembrane helix of ATP synthase subunit 6 （ATPase6）. Interestingly, these variations almost were detected in the non-obese T2DM patients with hypotension, including G8557A, A8563G, T8594C, C8609T, A8689G, G8998A and G9139A. Conclusions There were many variations in gene ATP6 and most of them are mitochondrial SNP, while variations A8689G, T8825C, G8920A, G8998A and G9139A may be mild mutations which may increase the susceptibility of T2DM. G8557A, A8563G, T8594C, C8609T, A8689G, G8998A and G9139A may be associated with the biogenetics diseases such diabetes and hypertension.