GENETIC HETEROGENEITY: EHLERS DANLOS SYNDROMES VII & IV

胶原蛋白是组织特异性结构蛋白家族，其 异常的生物合成可能会影响大多数生物的发育和完整性， 器官，包括皮肤、关节和血管（Ehlers-Danlos Syndrome）;骨 （成骨不全）;和主动脉和心脏（马凡氏综合征）。那里 在任何类别的患者中存在巨大的临床异质性， 反映了必须存在的分子异质性。遗传 胶原蛋白和其他细胞外基质成分的疾病， 弹性蛋白和纤连蛋白，提供了一个机会，了解结构和 皮肤和结缔组织的功能关系。的克隆 这些蛋白质的cDNA和基因以及聚合酶的发展 链式反应为分子方法提供了必要工具， 突变分析。 该项目将确定分子遗传缺陷， 先前研究的患有胶原蛋白生物合成障碍的患者： Ehlers-Danlos综合征和Buschke-Ollendorf综合征。蛋白质生物合成 SDS PAGE、肽图谱、Southern和北方印迹法已被广泛应用， 将用于识别患者进行更详细的分析。限制 片段长度多态性（RFLPS）将用于胶原单倍型 链等位基因在家庭中，以确定受影响的染色体（S）。的DNA 将使用RNAase A研究疑似点突变的患者 保护测定以定位突变。这些突变将被测序 通过从成纤维细胞mRNA进行第一链cDNA合成， 通过聚合酶链反应（PCR）扩增。使用不相等 当寡聚体的摩尔当量为1摩尔当量时，单链DNA分子可以是 在两个方向上扩增用于突变的直接DNA测序。以来 胶原蛋白对传统的蛋白质测序有抵抗力， 研究胶原蛋白生物合成异常的遗传学方法可能是 非常有用，提供有关结构和意义的信息， 胶原蛋白在皮肤形态发生，并导致发现遗传 标记和可识别的突变，用于产前诊断这些 紊乱

Collagens are a family of tissue specific structural proteins, whose abnormal biosynthesis may affect the development and integrity of most organs including skin, joints, and vessels (Ehlers-Danlos Syndromes); bone (Osteogenesis Imperfects); and aorta and heart (Marfan's Syndrome). There is tremendous clinical heterogeneity among patients in any category, reflecting the molecular heterogeneity which must be present. Genetic disorders of collagen, and other extracellular matrix components such as elastin and fibronectin, provide an opportunity to understand structure and functional relationships of skin and connective tissue. The cloning of the cDNAs and genes for these proteins plus the development of the polymerase chain reaction provide essential tools for a molecular approach for analysis of mutations. This project will identify molecular genetic defects in selected and previously studied patients with disorders of collagen biosynthesis: Ehlers-Danlos Syndrome and Buschke-Ollendorf Syndrome. Protein biosynthesis SDS PAGE, peptide mapping, Southern and Northern blotting have been and will be used to identify patients for more detailed analysis. Restriction fragment length polymorphisms (RFLPS) will be used to haplotype collagen chain alleles in families to identify the affected chromosome(s). DNA from patients suspected point mutations will be studied using RNAase A protection assays to localize mutations. These mutations will be sequenced by performing 1st strand CDNA synthesis from fibroblast MRNA and amplification by the polymerase chain reaction (PCR). By using unequal molar equivalents of oligomers, single stranded DNA molecules can be amplified in both directions for direct DNA sequencing of mutations. Since collagens are resistant to conventional protein sequencing, a molecular genetic approach to the study of abnormal collagen biosynthesis may be extremely useful, provide information on the structure and significance of collagen in skin morphogenesis, and lead to the discovery of genetic markers and identifiable mutations for prenatal diagnosis of these disorders.