糖尿病家系的分子遗传学研究

发布时间：2018-08-28 11:01

【摘要】：本课题分别作了糖尿病家系三个部分的研究：母系遗传的2个糖尿病家系线粒体基因组研究,成人起病的3个青少年糖尿病家系基因检测及功能分析,全基因组扫描在糖尿病家系的应用研究。前人研究表明线粒体DNA与2型糖尿病的发生有密切相关。本课题研究了两个具有相似外显率的母系遗传的2型糖尿病家系,进行线粒体全基因组测序,以期揭示线粒体DNA突变与2型糖尿病的相关性。这两个家系来自中国西南部,通过对两个家系先证者的线粒体基因组测序分析,发现家系A和家系B分别属于A4和D4h1单倍型。家系B的线粒体基因ND5具有一个私有突变G13759A,这个突变发生在线粒体基因的密码子的第一位上,可以引起氨基酸改变(丙氨酸变为苏氨酸)。但是进一步的进化和发育系统分析提示,这个突变有多个起源,可能是一个多态性位点,而不是致病的基因突变。在这两个具有相似的母系遗传背景的2型糖尿病家系中,我们没有发现线粒体基因的致病突变。除了线粒体基因以外,其他母系遗传基因突变(核基因或者核基因和线粒体基因相互作用)可能对中国人群的母系遗传2型糖尿病发挥作用。成人起病的青少年糖尿病(maturity-onset diabetes of the young, MODY)是25岁前发病,遗传至少3代,一种常染色体显性遗传的单基因遗传病的糖尿病类型。本课题对中国3个MODY家系中,进行了临床和MODY基因分析。分析的MODY基因有肝细胞核因子-4α(HNF-4α),GCK(葡萄糖激酶),肝细胞核因子-1α(HNF-1α),胰岛素启动因子-1(IPF-1),肝细胞核因子-1β (HNF1β),神经分化因子-1(NEUROD1),在这些MODY家系中发现了1个HNF4A变异(p.T130I)和2个HNF1A变异(p.I27L和p.S487N)。T130I能引起肝细胞核因子-4α的表达下降,与青少年糖尿病和成人糖尿病的发病都相关。我们进一步的功能都验证了HNF4A的p.T130I变异,可以改变HNF4A表达。HNF1A的p.S487N也是这些患者发生糖尿病的原因之一。本研究对p.T130I、p.I27L和p.S487N进行了保守性分析和功能预测,提示中国人群HNF4A和HNF1A变异可能是中国人群发生成人起病的青少年糖尿病的原因之一。本课题组对一个糖尿病家系的13名成员进行了全基因组扫描,经过TagSNP多点参数连锁分析以及多点非参数分析,并进行了单倍型分析,一个区段发现20号染色体23.5～30.8cM,16号染色体91.24～91.61cM的LOD值达到2附近,可能存在连锁遗传。这些区域有这几个基因和能量代谢相关：LCB1、PLCB4、 LAMP5、PAK7、SNAP25-AS1、SNAP25、MKKS、SLX4IP、JAG1。但我们将这些基因进行测序后没有发现有意义的突变位点。
[Abstract]:Three parts of the diabetes pedigree were studied: mitochondrial genome of 2 diabetic families inherited by matrilineal lineage, gene detection and functional analysis of 3 adolescent diabetic families with onset of disease in adults. Application of Genome scanning in Diabetes pedigree. Previous studies have shown that mitochondrial DNA is closely related to the development of type 2 diabetes. In order to reveal the correlation between mitochondrial DNA mutation and type 2 diabetes mellitus, we studied two maternal lineages of type 2 diabetes mellitus with similar extraneous rates, and sequenced the whole mitochondrial genome in order to reveal the relationship between mitochondrial DNA mutation and type 2 diabetes mellitus. The two families were from southwestern China. By sequencing the mitochondrial genome of the proband, we found that A and B belong to A4 and D4h1 haplotypes, respectively. Family B's mitochondrial gene ND5 has a private mutation, G13759A, which occurs in the first codon of the mitochondrial gene and can cause amino acid changes (alanine to threonine). But further evolutionary and developmental phylogenetic analysis suggests that the mutation has multiple origins and may be a polymorphic locus rather than a pathogenic gene mutation. No mutations in mitochondrial genes were found in these two type 2 diabetic families with similar maternal genetic background. In addition to mitochondrial genes, other maternal genetic mutations (nuclear genes or interactions between nuclear genes and mitochondrial genes) may play an important role in Chinese maternally inherited type 2 diabetes mellitus. Adult onset of adolescent diabetes (maturity-onset diabetes of the young, MODY) is an autosomal dominant single genetic disease type of diabetes mellitus, developed before the age of 25 and inherited for at least 3 generations). Clinical and MODY gene analysis were carried out in three MODY families in China. The MODY genes were identified as hepatic nuclear factor-4 伪 (HNF-4 伪), hepatic nuclear factor-1 伪 (HNF-1 伪), insulin promoter factor 1 (IPF-1), hepatic nuclear factor 1 尾 (HNF1 尾) and neural differentiation factor 1 (NEUROD1). One HNF4A mutation (p.T130I) and two HNF1A variants were found in these MODY families. Mutation (p.I27L and p.S487N). T130I induced a decrease in the expression of hepatocyte nuclear factor-4 伪. It is associated with both adolescent and adult diabetes. Our further function has confirmed that the p.T130I mutation of HNF4A, which can alter the expression of HNF4A. HNF1A p.S487N, is also one of the causes of diabetes in these patients. In this study, conservative analysis and functional prediction of p.T130I0I27L and p.S487N were carried out, suggesting that the variation of HNF4A and HNF1A in Chinese population may be one of the causes of diabetes mellitus in Chinese adults. The whole genome of 13 members of a diabetic family was scanned by TagSNP multipoint parameter linkage analysis and multipoint nonparametric analysis, and haplotype analysis was performed. It was found in one region that the LOD value of chromosome 20 was 30.8 cm and the LOD value of chromosome 16 was about 2, which might be linked inheritance. These regions have these genes associated with energy metabolism: LCB1, PLCB4, LAMP5,PAK7,SNAP25-AS1,SNAP25,MKKS,SLX4IP,JAG1. However, we sequenced these genes and found no significant mutation sites.
【学位授予单位】：云南大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：R587.1

【共引文献】