中国人2型糖尿病人群中线粒体基因突变的发生率及其临床特点的研究

Prevalence and clinical characteristics of mitochondrial mutations in Chinese patients with type 2 diabetes

目的 了解线粒体 t RNAL eu( UUR) nt32 43A→ G突变在中国人 2型糖尿病人群中的精确发病率及该基因突变所导致的 2型糖尿病的临床特征。方法 采用 PCR- RFL P技术对 716例随机抽取的无亲缘关系的 2型糖尿病患者进行了该突变的筛查。结果 在 2型糖尿病组中发现 3例该基因突变携带者 ,代表了被筛选人群的 0 .4%。此外 ,本研究还对近年来报道的与日本人 2型糖尿病相关的 ND1基因 nt3316 G→ A突变进行了筛查 ,在 2型糖尿病组中发现 16例(2 .2 % )突变携带者 ,在 181例正常对照组中发现 5例突变携带者 (2 .7% ) ,突变的发生率在两组间无显著性差异。携带mt3316位点 G→ A突变的 2型糖尿病组与无该突变的 2型糖尿病组之间的临床特点 (发病年龄 ,体重指数 ,胰岛素分泌功能 )比较亦无显著性差异。结论 mt3316位点

Objective To assess the prevalence of the A to G mutation at position 3243 of the mitochondrial tRNA Leu(UUR) gene in type 2 diabetes in a Chinese population. Methods We screened 716 randomly selected, unrelated patients with type 2 diabetes for the mutation with a PCR RFLP technique.Results Three individuals with this mutation were identified, representing approximately 0 4% of the type 2 patients screened. Further screening of first degree relatives of these 3 patients identified another 4 affected carriers. In comparison with type 2 diabetic patients without the mutation, these 7 carriers of the mt3243 mutation had:①an earlier onset of diabetes (38 0±10 1 yr vs 53 4±10 0 yr, P<0 001);②lower BMI (19 5±2 0 vs 24 9±10 9, P<0 0001);and ③ lower post challenge insulin levels (Area under the curve of insulin levels during the OGTT, 2946±1647 2 vs 7469±6647 7, P<0 01). In addition, we screened the same 716 patients with type 2 diabetes, as well as 181 controls with normal glucose tolerance, for a newly described mt 3316 G→A mutation. This mutation was found in 16 patients with type 2 diabetes (2 2%) and 5 controls (2 7%). Therefore, the frequency of the mutation was not different between patients and controls. Moreover, clinical characteristics such as age of onset of diabetes, BMI, and insulin levels were not different between diabetic patients with the mt3316 mutation and those without it.Conclusion The mt3316 G→A mutation is a polymorphism unrelated to diabetes.