伴线粒体基因突变的家族性糖尿病的临床特征

目的探讨由线粒体ｔＲＮＡＬｅｕ（ＵＵＲ）（ｍｔＤＮＡ）３２４３Ａ→Ｇ点突变引起的糖尿病亚型的临床特征。方法按ＷＨＯ的标准，采用基因诊断技术，对１３０例伴有糖尿病家族史的病人，其中包括胰岛素依赖型糖尿病（ＩＤＤＭ）和非胰岛素依赖型糖尿病（ＮＩＤＤＭ）进行筛查。并对其中３例阳性者的家系进行临床及基因分析。结果从１３０例糖尿病患者中共检出４例（３．１％）伴有ｍｔＤＮＡ３２４３点突变的非亲缘关系的病人，然后从其中３例突变病人及其家系中检测出９例线粒体糖尿病。全部患者均为消瘦体型。其中８例伴有神经性耳聋，８例因对口服降糖药继发性失效需改用胰岛素治疗。结论由于这类病人具有母系遗传、耳聋、进行性胰岛素分泌不全等特征，临床上可将这一类型的糠尿病分为一种新亚型－ＭＩＤＤ。

Clinical characterizations of familial diabete mellitus associated with mitochondrial gene mutation

Objective To discuss clinical features at diabetic subtype which is apparently caused by a single mutation in the mitochondrial tRNA Leu(UUR) gene.Methods According to WHO criteria of diabetes mellitus (DM), 130 patients with DM and the family history of DM (either NIDDM or IDDM) were screened by using genetic diagnosis. Clinical and laboratory analyses were made in three unrelated patients with the mutation in mtDNA and their relatives. Results Four unrelated subjects(3.1%) were detected with mutation at position 3243 of mitochondrial DNA. Then nine diabetes patients from first degree relatives of three probands were also identified with the mutation, in which eight patients were associated with sensory hearing loss and required insulin therapy due to secondary failure to oral hypoglycemic agents. All these nine patients had a lower frequency of obesity in the past, and most of them had a mother with diabetes, were younger at diagnosis, and were generally accompanied by impaired insulin secretion.Conclusion Since the patients have the clinical characteristics of maternal transmission, hearing loss and impaired insulin secretion, we conclude that maternally inherited diabetes and deafness (MIDD) is a new diabetes subtype associated with a single mitochondrial mutation.