家族性糖尿病人群中线粒体ND4基因12026 A→G突变的分析研究

目的了解线粒体ND4基因mt12026A→G变异在中国人家族性糖尿病人群中的发生率及其临床特点。方法应用PCR-限制性片段长度多态性技术结合直接测序方法对随机抽取的无亲缘关系的770个糖尿病家系的先证者及309名非糖尿病对照者进行线粒体基因mt12026A→G变异的筛查。结果在糖尿病先证者组中发现28例（3．63％）mt12026A→G变异，而在正常对照组中发现9例（2．91％），两组间变异的发生率差异无统计学意义。伴mt12026A→G的糖尿病组与无该变异的糖尿病组之间的临床特点（年龄、体重指数、胰岛素抵抗指数）比较差异无统计学意义。结论线粒体ND4基因mt12026A→G变异可能不是中国人线粒体糖尿病发病的致病原因，而是中国人线粒体的一种基因多态。

Prevalence and clinical characteristics of the A to G variant at position 12026 of the mitochondrial ND4 gene in familial diabetes mellitus in Chinese population

OBJECTIVE: To assess the prevalence of the A to G variant at nucleotide 12026 (mt12026) of the mitochondrial NADH-dehydrogenase subunit 4 (ND4) gene in familial diabetes mellitus in Chinese population. METHODS: The authors screened 770 randomly selected, unrelated probands of diabetic pedigrees, and 309 controls with normal glucose tolerance for the variant by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique and PCR-direct-sequencing. RESULTS: The mt12026 A --> G variant was detected in 28 diabetic patients (3.63%) and 9 controls (2.91%). The frequency of the variant mt12026 A --> G was not statistically different between diabetic patients and controls. Moreover, clinical characteristics such as age, body mass index (BMI), and insulin resistant index were not different between diabetic patients with and without the mt12026 mutation. CONCLUSION: The mt12026 A --> G variant is a mitochondrial gene polymorphism in Chinese population, and it is unlikely that the mutation is in itself the cause of diabetes.