MAPPING, GENE IDENTIFICATION AND DETECTION OF MUTATIONS IN CHROMOSOME 22

圆锥动脉干型先天性心脏病（CHD）患者的一个亚组 已经显示有22q11.2的微缺失。 删除的区域 很大，可能编码几个相邻的基因。 开始 为了了解这种特殊染色体片段的半合子性 引起所见的心脏缺陷，该区域必须小心 分析并鉴定基因。 为了实现这一目标，我们建议 该地区的详细物理地图，并使用此地图隔离 重叠克隆的来自YACs和cosmetic的基因组DNA片段。 DNA 来自选定的CHD患者子集的样本将用于缩小 关键区域。 特别是， 将研究具有较小缺失的代表，以解剖出 可能负责锥体干的区域内的基因 在这些患者中观察到的畸形。 将使用多种方法 来鉴定和分离该区域的cDNA 这些方法将 包括直接绘制新分离22号染色体特异性基因 使用YAC选择映射到关键区域的cDNA， 对从大规模野生动物中获得的DNA序列进行了克隆和计算机分析， 关键区域的规模排序。 在这本书中找到的文字记录 方式将通过PCR-PCR杂交或PCR-PCR杂交来确认和分离。 基于战略。 因此，重要的发育调控基因将 被识别和表征。 它们在冠心病发病机制中的作用 将被审查。

A subset of conotruncal congenital heart disease (CHD) patients studied have been shown to have microdeletions of 22q11.2. The region deleted is large and is likely to code for several contiguous genes. To begin to understand how hemizygosity of this particular chromosomal segment gives rise to the cardiac defects seen, this region must be carefully analyzed and the genes identified. To accomplish this we propose to make a detailed physical map of the region and use this map to isolate overlapping cloned genomic DNA fragments from YACs and cosmids. DNA samples from a selected subset of CHD patients will be used to narrow the critical region. In particular, the breakpoints of patients who represent with smaller deletions will be studied to dissect out the gene(s) within the region likely to be responsible for the conotruncal malformations observed in these patients. Multiple methods will be used to identify and isolate cDNAs from the region. These methods will include mapping of newly isolated chromosome 22-specific genes, directly selecting for cDNAs which map to the critical region using YACs and cosmids and computer analysis of the DNA sequence obtained from large scale sequencing of the critical region. Transcripts identified in this manner will be confirmed and isolated by either hybridization of PCR- based strategies. Thus, important developmentally regulated genes will be identified and characterized. Their role in the pathogenesis of CHD will be examined.