Genetic Heterogeneity and Protein Function in DBA

DBA 中的遗传异质性和蛋白质功能

• 批准号: 6383682
• 负责人: COLIN A SIEFF
• 金额: $ 42.91万
• 依托单位: DANA-FARBER CANCER INST
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-08-15 至 2004-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6383682
• 关键词: anemia; autosomal dominant trait; chromosome aberrations; comparative genomic hybridization; congenital blood disorder; erythropoiesis; family genetics; gene expression; gene mutation; genetic mapping; human subject; in situ hybridization; linkage mapping; loss of heterozygosity; microarray technology; molecular pathology; patient oriented research; polymerase chain reaction; protein structure function; single strand conformation polymorphism

Diamond Blackfan anemia (DBA) is a congenital anemia that develops at birth or soon after, and is due to failure of production of erythrocytes and their precursors, with normal or near normal myeloid and platelet lineages. Patients can emit completely on corticosteroids or may become resistant to treatment, and then require regular blood transfusions, or bone marrow transplant if a histocompatible sibling donor is available. DBA patients are at increased risk of developing leukemia and other malignancies. DBA is inherited in about 10-15 percent of cases, mostly as an autosomal dominant. Recent genetic studies have led to the the surprising identification of mutations in a ribosomal protein gene, RPS19, on chromosome 19q13.2, in about 25 percent of both familial and sporadic cases (DBA1). Linkage analysis in multiplex DBA families shows strong evidence for another gene on chromosome 8p (DBA2) in about 40 percent of families, and other pedigrees do not show evidence for linkage to either chromosome 8p or 19q, indicating further genetic heterogeneity. The long term objective of this proposal is to identify and isolate the DBA2 gene. Therefore the specific aims are to (1), further define the chromosome 8p genetic map by ascertaining more families to search by linkage and haplotype analysis for recombinations in the flanking regions, and screen by cytogenetic techniques for deletions and translocations; (2) use cDNA arrays of the genes and expressed sequence tags (ESTs) in the critical region to define candidate genes by examining their pattern of expressed RNAs in erythroid cells, and by comparing the hybridization of normal and patient genomic DNA to these arrays to look for loss of heterozygosity; and (3), test candidate genes identified either as a result of progress in aim 1 and/or aim 2 for mutations in chromosome 8 linked families by SSCP, PCR heterozygosity screening and sequence analysis. Knowledge of additional genes that cause DBA may offer new insights into the molecular regulation of erythropoiesis and the process of stem cell commitment to the erythroid lineage, and it is possible that the protein encoded by the gene on chromosome 8p interacts with RPS19 in a novel pathway. Furthermore, the increased risk of malignancy in these patients suggests that the protein may act as a tumor suppressor. Thus isolating the genes that cause DBA may be important not only for devising new treatment for these patients but also for a better understanding of the regulation of erythropoiesis and the development of malignancy.

Diamond Blackfan贫血（DBA）是一种先天性贫血，在出生时或之后不久就会发育，这是由于红细胞及其前体的产生失败，其正常或接近正常的髓样和血小板谱系。 患者可以完全在皮质类固醇上发射或可能对治疗有抵抗力，然后需要定期输血，或者如果有组织兼容的同胞供体，则需要骨髓移植。 DBA患者患白血病和其他恶性肿瘤的风险增加。 DBA在约10-15％的病例中继承，主要是常染色体主导。 最近的遗传研究导致在大约25％的家族性和零星病例中，核糖体蛋白基因RPS19，RPS19，RPS19的突变令人惊讶（DBA1）。 多重DBA家族中的链接分析显示了大约40％家族染色体8p（DBA2）的另一个基因的有力证据，而其他血统则没有显示与8p或19q染色体染色体的证据，表明进一步的遗传异质性。 该提案的长期目标是识别和隔离DBA2基因。 因此，具体的目的是（1），通过确定更多的家族来通过连锁和单倍型分析进行搜索，以进一步定义8P遗传图，以进行侧翼区域的重组，并通过细胞遗传学技术筛选缺失和易位的细胞遗传学技术； （2）使用基因的cDNA阵列和临界区域中的表达序列标签（EST）来定义候选基因，通过检查其在红细胞细胞中表达的RNA的模式，并通过比较正常和患者基因组DNA的杂交与这些阵列的杂交以寻找杂合子的损失； （3），通过SSCP，PCR杂合性筛选和序列分析在AIM 1和/或AIM 2中确定的测试候选基因。对引起DBA的其他基因的了解可能会为红细胞生成的分子调节和干细胞对红细胞性谱系的承诺的过程提供新的见解，并且在8P染色体上，基因编码的蛋白质可能与RPS19相互作用。 此外，这些患者的恶性肿瘤风险增加表明该蛋白可能是肿瘤抑制剂。 因此，隔离引起DBA的基因不仅对于为这些患者设计新治疗，而且对于更好地理解了促红细胞生成的调节和恶性肿瘤的发展很重要。