眼科遗传疾病的分子遗传学分析
发布时间：2018-10-21 07:53
【摘要】： 眼遗传病是当前儿童和青少年的主要致盲性眼病之一。根据遗传方式可分为四种主要类型:常染色体显性遗传病、常染色体隐性遗传病,性染色体连锁遗传病,和线粒体遗传病。在众多眼遗传病中,先天性白内障和视神经萎缩占有重要位置,本论文对这两种眼科遗传病进行分子遗传研究,开展遗传连锁分析和致病突变检测。 白内障是指晶状体出现浑浊的病理状态,按发病时间可被分为先天性和年龄相关性白内障。先天性白内障通常在患者出生时或不久就出现,该病呈现出高度的遗传以及临床异质性。 (1)在一全白内障中国家系中,我们发现致病基因与微卫星多态标记D16S3043连锁,进一步单倍型分析将其定位于D16S515和D16S415标记之间,对该区域内HSF4基因测序发现第74位密码子由精氨酸突变为组氨酸(p.R74H),该突变在家系中与疾病共分离,同时对150个正常对照的RFLP分析也没有发现该突变。该结果丰富了HSF4基因突变导致的白内障的临床表现谱。 (2)在另一后极性白内障家系中,连锁和单倍型分析将该家系致病基因定位在11q22-22.3区域,最大LOD值为4.52,对CRYAB基因测序发现第20位密码子由脯氨酸突变为丝氨酸(p.P20S),该突变在此家系中与白内障共分离,在200个正常人中,用SSCP分析未检测到这一突变。该结果有力地证实了CRYAB基因突变可以导致白内障。 视神经纤维退化和相关血管系统病变会导致视力受损,这种病理学状态被称为视神经萎缩(OA)。遗传性OA可分为两大类:原发性OA和继发性OA,原发性OA包括常染色体视神经萎缩(ADOA)和Leber’s视神经萎缩(LHON)等类型。由于OA遗传和临床表型的高度异质性,因此其诊断较为困难。 (3)通过一个ADOA家系的连锁分析以及测序和RFLP,鉴定出OPA1基因的一个错义突变(p.G401D),经RFLP分析证明该突变只存在于该家系患者,不存在于家系中健康人和150个正常人中,而且病人呈现出视神经萎缩以及听力受损综合征状。该结果支持OPA1突变导致的视神经萎缩可伴随有听力受损。 (4)我们对一个LHON家系进行临床分析,发现家系内患者整体预后良好,实属罕见;对家系成员进行了线粒体DNA的3个原发突变位点检测,发现病人携带mtG11778A位点突变,而且多名病人和突变携带者呈现出异质性突变;对相关继发突变位点的检测没有发现次级突变的存在。该结果表明可能存在其它因子对该家系的表型起调节作用。 所有这些分子遗传学研究为阐明先天性白内障和视神经疾病的病理学,以及提供更好的遗传咨询和最终发展有效疾病治疗策略提供了有益的帮助。
[Abstract]:Eye-hereditary disease is one of the leading causes of blindness in children and adolescents. According to the genetic pattern, there are four main types: autosomal dominant disease, autosomal recessive hereditary disease, sex chromosome linked genetic disease, and mitochondrial genetic disease. Congenital cataract and optic atrophy play an important role in many ophthalmic hereditary diseases. In this paper, molecular genetic analysis, genetic linkage analysis and pathogenic mutation detection of these two kinds of ophthalmic hereditary diseases were carried out. Cataract refers to the pathological state of lens opacity, which can be divided into congenital cataract and age-related cataract according to the onset time. Congenital cataract usually occurs at birth or shortly after birth, showing a high degree of genetic and clinical heterogeneity. We found that the pathogenicity gene was linked to microsatellite polymorphic marker D16S3043, and further haplotype analysis mapped it between D16S515 and D16S415 markers. The HSF4 gene in this region was sequenced from arginine to histidine (p.R74H) at codon 74. The mutation was isolated from the disease at home, and the mutation was not detected by RFLP analysis of 150 normal controls. The results enriched the clinical manifestations of cataract caused by mutation of HSF4 gene. (2) in another pedigree with post-polar cataract, linkage and haplotype analysis located the pathogenic gene in 11q22-22.3 region. The maximum LOD value was 4.52. The CRYAB gene was sequenced from proline to serine (p.P20S). The mutation was separated from cataract in this pedigree and was not detected by SSCP analysis in 200 normal subjects. The results strongly confirm that mutations in the CRYAB gene can lead to cataracts. Optic nerve fiber degeneration and associated vascular system lesions can lead to visual impairment, a pathological condition known as optic nerve atrophy (OA).) Hereditary OA can be divided into two categories: primary OA and secondary OA, primary OA including autosomal optic atrophy (ADOA) and Leber's optic atrophy (LHON). Due to the high heterogeneity of genetic and clinical phenotypes of OA, Therefore, it is difficult to diagnose OPA1 gene. (3) A missense mutation (p.G401D) of OPA1 gene was identified by linkage analysis, sequencing and RFLP, analysis of a ADOA pedigree. It does not exist in healthy people and 150 normal people, and the patient presents optic atrophy and hearing loss syndrome. The results support that the optic atrophy caused by OPA1 mutation may be accompanied by hearing impairment. (4) A clinical analysis of a LHON family showed that the overall prognosis of the patients in the family was good, which was rare. Three primary mutation sites of mitochondrial DNA were detected among family members. It was found that the patients carried mtG11778A mutation, and many patients and mutants showed heterogeneity. No secondary mutation was found in the detection of related secondary mutation sites. These results suggest that there may be other factors regulating the phenotype of the family. All of these molecular genetic studies are helpful to clarify the pathology of congenital cataract and optic nerve diseases, to provide better genetic counseling and to develop effective treatment strategies.
【学位授予单位】：华中科技大学
【学位级别】：博士
【学位授予年份】：2006
【分类号】：R77;R394
本文编号：2284451
[Abstract]:Eye-hereditary disease is one of the leading causes of blindness in children and adolescents. According to the genetic pattern, there are four main types: autosomal dominant disease, autosomal recessive hereditary disease, sex chromosome linked genetic disease, and mitochondrial genetic disease. Congenital cataract and optic atrophy play an important role in many ophthalmic hereditary diseases. In this paper, molecular genetic analysis, genetic linkage analysis and pathogenic mutation detection of these two kinds of ophthalmic hereditary diseases were carried out. Cataract refers to the pathological state of lens opacity, which can be divided into congenital cataract and age-related cataract according to the onset time. Congenital cataract usually occurs at birth or shortly after birth, showing a high degree of genetic and clinical heterogeneity. We found that the pathogenicity gene was linked to microsatellite polymorphic marker D16S3043, and further haplotype analysis mapped it between D16S515 and D16S415 markers. The HSF4 gene in this region was sequenced from arginine to histidine (p.R74H) at codon 74. The mutation was isolated from the disease at home, and the mutation was not detected by RFLP analysis of 150 normal controls. The results enriched the clinical manifestations of cataract caused by mutation of HSF4 gene. (2) in another pedigree with post-polar cataract, linkage and haplotype analysis located the pathogenic gene in 11q22-22.3 region. The maximum LOD value was 4.52. The CRYAB gene was sequenced from proline to serine (p.P20S). The mutation was separated from cataract in this pedigree and was not detected by SSCP analysis in 200 normal subjects. The results strongly confirm that mutations in the CRYAB gene can lead to cataracts. Optic nerve fiber degeneration and associated vascular system lesions can lead to visual impairment, a pathological condition known as optic nerve atrophy (OA).) Hereditary OA can be divided into two categories: primary OA and secondary OA, primary OA including autosomal optic atrophy (ADOA) and Leber's optic atrophy (LHON). Due to the high heterogeneity of genetic and clinical phenotypes of OA, Therefore, it is difficult to diagnose OPA1 gene. (3) A missense mutation (p.G401D) of OPA1 gene was identified by linkage analysis, sequencing and RFLP, analysis of a ADOA pedigree. It does not exist in healthy people and 150 normal people, and the patient presents optic atrophy and hearing loss syndrome. The results support that the optic atrophy caused by OPA1 mutation may be accompanied by hearing impairment. (4) A clinical analysis of a LHON family showed that the overall prognosis of the patients in the family was good, which was rare. Three primary mutation sites of mitochondrial DNA were detected among family members. It was found that the patients carried mtG11778A mutation, and many patients and mutants showed heterogeneity. No secondary mutation was found in the detection of related secondary mutation sites. These results suggest that there may be other factors regulating the phenotype of the family. All of these molecular genetic studies are helpful to clarify the pathology of congenital cataract and optic nerve diseases, to provide better genetic counseling and to develop effective treatment strategies.
【学位授予单位】：华中科技大学
【学位级别】：博士
【学位授予年份】：2006
【分类号】：R77;R394
【参考文献】
相关期刊论文 前5条
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