Chromosomal microdeletions causing heart defects

描述(申请人提供)：圆锥干畸形是临床上严重的先天性心脏畸形，影响发育中心脏的流出道。这些圆锥干心脏缺陷的病因在很大程度上是未知的，但它们可能是异质性的，涉及环境和遗传因素。拟议的研究计划将继续把重点放在检测圆锥干心脏缺陷的遗传因素上。我们在NHLBI R01 HL092330的支持下，对391例圆锥干缺陷儿进行了阵列比较杂交。我们发现，在患有法乐四联症的男孩中，有近2%的人有额外的性染色体物质。我们还成功地利用细菌人工染色体阵列比较基因组杂交(ARRAY-CGH)检测了7例新的亚显微染色体缺失，涉及染色体22q11、1q和10q23p以及8q21和8p23重复。基于ARRAY-CGH发现的一个新的CRKL基因微缺失，我们将进行下一代DNA测序，以确定851名患有圆锥干心脏缺陷的加州婴儿的信号通路FAK-CRKL-ERK1/ERK2的基因突变。小鼠实验表明，这条通路是颅神经脊细胞迁移到心脏发育中的流出道的重要信号通路。但几乎有 目前尚不清楚这一途径中的基因序列变异对人类圆锥干缺陷的潜在贡献。我们还将使用ARRAY-CGH研究发现缺失和复制的三个染色体区域。我们将使用三个基因座的关联研究来缩小候选染色体区域。然后，我们将再次转向下一代DNA测序，以确定位于染色体微缺失/重复内的候选基因或调控元件的突变。这项研究的结果应该会导致对出生时患有圆锥干心脏缺陷的儿童进行更全面、更临床适用的测试。我们研究的圆锥干缺陷儿人群异常庞大，并为出生时患有圆锥干缺陷症的儿童提供了独特的基于人群的调查。总体而言，我们的研究计划试图加强我们对圆锥干缺陷遗传原因的科学理解。由于圆锥干缺陷会导致相当大的发病率，以及高昂的情感和经济成本，扩大我们对其原因的理解可能会导致预防性干预，这将极大地造福于公共卫生和社会。

DESCRIPTION (provided by applicant): Conotruncal defects are clinically serious congenital heart malformations affecting the outflow tract of the developing heart. The etiologies of these conotruncal heart defects are largely unknown, but they are likely heterogeneous, involving environmental and genetic factors. The proposed research program will continue our focus on detecting genetic contributions to conotruncal heart defects. We have been supported by NHLBI R01 HL092330 to perform array comparative hybridization of 391 infants with conotruncal defects. We found that nearly 2% of boys with tetralogy of Fallot have an extra sex chromosome material. We have also successfully employed bacterial artificial chromosome array comparative genomic hybridization (array-CGH) to detect seven infants with novel submicroscopic chromosomal deletions involving chromosomes 22q11, 1q, and 10q23p and duplications of 8q21 and 8p23. Based on a novel microdeletion of the gene CRKL that we found by array-CGH, we will perform Next Generation DNA sequencing to identify mutations of genes of the signaling pathway FAK-CRKL-Erk1/Erk2 among 851 California infants with conotruncal heart defects. Murine experiments have shown that this pathway is an essential signaling pathway for cranial neural crest cells that migrate into the developing outflow tract of the heart. But there is almost nothing known about the potential contribution of sequence variation of the genes in this pathway to conotruncal defects in humans. We will also investigate three chromosomal regions where we found deletions and a duplication using array-CGH. We will use association studies of the three loci to narrow the candidate chromosomal regions. Then, we will turn to e Next Generation DNA sequencing again to identify mutations of candidate genes or regulatory elements that are located within the chromosomal microdeletions/duplication. The results of this research should lead to the development of more comprehensive, clinically applicable testing for children born with conotruncal heart defects. Our study populations of infants with conotruncal defects are unusually large and offer unique population-based investigations of children born with conotruncal defects. Overall, our research program attempts to enhance our scientific understanding of the genetic causes of conotruncal defects. Because conotruncal defects result in substantial morbidity, as well as high emotional and economic costs, expanding our understanding of their causes may lead to preventive interventions that would greatly benefit public health and society.