Danon综合征LAMP2基因突变分析和微卫星多态标志STR在遗传病分析中的应用研究

发布时间：2018-02-14 12:54

本文关键词： Danon综合征 LAMP2 DMD/BMD STR HA HMO EXT1 EXT2　出处：《浙江大学》2012年硕士论文　论文类型：学位论文

【摘要】：第一部分的研究工作中,我们收集了两个患有Danon综合征的中国人家系,进行了分子遗传学分析。 Danon综合征(OMIM#300257)是一种罕见的X连锁显性遗传病,该病的早发症状和体征主要包括心肌肥厚,骨骼肌病和智力发育迟缓。致病基因LAMP2(lysosome-associated membrane protein-2, LAMP2)位于Xq24,由9个外显子组成,第9外显子有不同剪切产生2种异构体。LAMP2基因全长43218bp,编码含410个氨基酸的溶酶体相关膜蛋白2(LAMP2)[GeneCards: http://www.genecards.org/cgi-bin/carddisp.pl?gene=LAMP2],是一种高度糖基化的溶酶体膜蛋白,参与维持溶酶体膜的完整性以及作为一种转运受体协助蛋白进入溶酶体。本病的病理特点是在骨骼肌和心肌细胞内存在含有自噬物质和糖原的胞浆内空泡。Danon综合征的主要临床特征男性患者和女性患者存在明显的不同。男性患者通常表现典型的症状,心肌肥厚,骨骼肌病和智力发育迟缓,常在20岁前发病,大多数在30岁之前死亡。女性患者发病时间比男性晚,临床症状和表现比男性患者轻,她们的症状通常只涉及心肌。自Nishino首次发现LAMP2基因的8个突变,目前已有40多种不同突变在文献中报道。本研究中,在两个中国家庭的两位男性患者中检测到两个LAMP2基因的新突变(c.808dupG和c.317-320dupCATC),二者都造成移码突变,引起Danon综合征。新突变的检出丰富了Danon综合征数据库的信息。第二部分的研究,是利用微卫星多态标志(STR)对6个遗传病家系进行了连锁分析,其中包括4个杜氏(贝氏)进行性肌营养不良症(Duchenne Muscular Dystrophy/Baker Muscular Dystrophy, DMD/BMD)家系、1个血友病A(Hemophilia A, HA)家系和一个遗传性多发性骨软骨瘤(Hereditary Multiple Osteochondromas, HMO)家系。微卫星多态标志(Microsatellite, MS)又称短串联重复序列(Short tandem repeats, STR),是一种广泛存在于人类基因组,以2-6个碱基为单位、串联重复排列的序列。一般每个微卫星位点有十几个等位片段,具有高度的多态性,并符合孟德尔共显性遗传的特点,具有高杂合度和多态信息量,可以作为一种遗传标记用于遗传性疾病的诊断。采用PCR和STR连锁分析法可以判断遗传病基因的走向,对遗传性疾病基因诊断和产前诊断有重要意义。本研究中,我们采用微卫星标记对DMD/BMD家系、HA家系和HMO家系进行连锁分析,探讨STR在致病基因连锁分析和产前诊断应用中的意义以及局限性。
[Abstract]:In the first part, we collected two Chinese families with Danon syndrome for molecular genetic analysis. Danon syndrome (OMIM #300257) is a rare X-linked dominant hereditary disease. Its early onset symptoms and signs mainly include myocardial hypertrophy, skeletal myopathy and mental retardation. The pathogenic gene LAMP2(lysosome-associated membrane protein-2 (LAMP2) is located in Xq24 and consists of nine exons. Exon 9 has two isoforms produced by different splicing. LAMP2 gene is 43218bp in length and encodes lysosomal associated membrane protein 2GLAMP2 containing 410 amino acids. [gene Cardshttpwt / / www.genecards.orgcgi-bincarddisp.pl.] [GeneCards. / / www.genecards.orgcgi-bincard.pl. Gene=LAMP2 is a highly glycosylated lysosomal membrane protein. It is involved in maintaining the integrity of lysosomal membrane and entering lysosome as a transporter receptor assisting protein. The pathological features of the disease are the presence of cytosolic vacuoles containing autophagy and glycogen in skeletal muscle and cardiomyocytes. The main clinical features of the symptoms are significant differences between male and female patients. Male patients usually exhibit typical symptoms, Myocardial hypertrophy, skeletal myopathy and mental retardation often occur before the age of 20, and most of them die before the age of 30. The onset time of female patients is later than that of men, and their clinical symptoms and manifestations are lighter than that of male patients. Their symptoms usually involve only the myocardium. Eight mutations of LAMP2 gene have been first discovered by Nishino, and more than 40 different mutations have been reported in the literature. Two new mutations of LAMP2 gene, c.808dupG and c.317-320dupCATCG, were detected in two male patients from two Chinese families, both of which caused the Danon syndrome. The detection of the new mutation enriched the information of Danon syndrome database. In the second part, the linkage analysis of 6 families with hereditary diseases was carried out by using microsatellite polymorphism marker (STR). These include four Duchenne Muscular Dystrophy/Baker Muscular dystrophyts, one hemophilia Hemophilia A, and one hereditary multiple Multiple Osteochondromas. microsatellite polymorphism marker MSM. Short tandem repeats, short tandem repeats, are widely found in the human genome. Sequences arranged in tandem repetition in units of 2-6 bases. In general, each microsatellite locus has more than a dozen alleles, highly polymorphic, consistent with the characteristics of Mendelian codominant inheritance, with high heterozygosity and polymorphic information. It can be used as a genetic marker for the diagnosis of genetic diseases. PCR and STR linkage analysis can be used to determine the trend of genetic disease genes, which is of great significance for genetic diagnosis and prenatal diagnosis of hereditary diseases. In this study, we used microsatellite markers to analyze the linkage between HA and HMO families of DMD/BMD families, and to explore the significance and limitation of STR in the linkage analysis of pathogenic genes and prenatal diagnosis.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R394.1

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