DNA LINKAGE STUDY OF CLEFT LIP AND PALATE

本项目的总体目标是阐明 遗传性非综合征性唇裂伴或不伴腭裂（CLP）。 面裂的原因是非常异质性与CLP是 超过100种可识别的综合征的一部分，但更常见的是， 作为孤立的畸形发生。 在后一组中， 疾病，称为非综合征型CLP，我们最近已经表明遗传 异质性，但已经确定了一组同质的 常染色体显性遗传CLP多代家系。 这些 多代同堂的家庭已经得到了很好的描述，这是关键的一步， 以阐明分子机制和识别 负责的基因。 在最初的研究中，我们已经表明， 常染色体显性基因是导致某些CLP病例的原因， 排除了CLP与转化生长因子α的紧密连接， 以前曾报道与遗传性CLP有关。 这 建议是资金继续我们的研究， 常染色体显性唇腭裂基因座先前由一个 （三）小额贷款（RO3） 在这个持续的项目中，我们建议 使用两种方法定位引起非综合征型CLP的常染色体基因座（或多个基因座）， “候选基因”和“反向遗传学”方法。 我们正处在一个独特的 实现这一目标，因为我们已经确定了同质 多代常染色体显性遗传CLP家族，分子 定位基因座的技术是可用的， 生物学上相关的候选基因是可用的。 动物研究最近提供了新的见解颅面 胚胎发生和细胞间相互作用的作用。 从这些 通过观察，已经选择了14个候选基因进行研究， Sourmycel方法学。 受影响的限制性片段模式 将检查个体的总染色体重排，如 如删除或插入。 将检测多态性位点的连锁 在多代同堂的家庭中， 与中电息息相关。 如果排除紧密连锁， 将用于构建连锁排除图。 最后如果 排除与候选基因的连锁，系统搜索 将使用可变数目串联重复探针进行基因组分析， 多限制性位点多态性和聚合酶链反应 可检测的多态性以检测与CLP基因座的连锁。 排除 从以前的连锁研究和排除在这个基因座的地图 研究将用于研究的目标领域。 导出的信息 本研究将为1）阐明具体的 在这些多代家庭中引起遗传性CLP的突变， 2)表征病症的发病机理，以及3）提供 为有CLP风险的家庭提供具体的咨询信息。 关于遗传性CLP的信息也可能有助于了解 涉及散发性非综合征型CLP和其他 由于胚胎发育异常而引起的疾病。

The overall aim of this project is to delineate the molecular mechanisms of heritable nonsyndromic cleft lip with or without cleft palate (CLP). The causes of facial clefting are extremely heterogeneous with CLP being part of greater than 100 recognizable syndromes but, more commonly, occurring as an isolated malformation. Within the latter group of disorders, called nonsyndromic CLP, we have recently shown genetic heterogeneity but have identified a homogeneous group of multigenerational families with autosomal dominant CLP. These multigenerational families have been well characterized, a crucial step towards elucidating the molecular mechanisms and the identification of the gene(s) responsible. In the initial study, we have shown that autosomal dominant gene is responsible for some of the cases of CLP and excluded tight linkage of CLP to transforming growth factor alpha which had previously been reported to be associated with heritable CLP. This proposal is for funds to continue our studies characterizing an autosomal dominant cleft lip and palate locus previously supported by a small grant (RO3) from the NIDR. In this continuing project, we propose to map an autosomal locus (or loci) causing nonsyndromic CLP using both "candidate gene" and "reverse genetics" approaches. We are in a unique position to accomplish this goal because we have identified homogeneous multigenerational families with autosomal dominant CLP, the molecular technology to localize the locus (loci) is available and a number of biologically pertinent candidate genes are available. Animal studies have recently provided new insights into craniofacial embryogenesis and the role of cell-cell interactions. From these observations, fourteen candidate genes have been selected for study by Sourthern gel methodology. Restriction fragment patterns from affected individuals will be examined for gross chromosomal rearrangements, such as deletions or insertions. Linkage to polymorphic sites will be tested in the multigenerational families to determine whether candidate genes are tightly linked to CLP. If tight linkage is excluded, the formation will be used in constructing linkage exclusion maps. Finally, if linkage to the candidate genes is excluded, a systemic search of the genome will be undertaken using variable number tandem repeat probes, multiple restriction site polymorphisms, and polymerase chain reaction detectable polymorphisms to detect linkage to a CLP locus. An exclusion map developed from previous linkage studies and loci excluded in this study will be used to target areas for study. Information derived from this study will provide a basis for 1) elucidating the specific mutation(s) causing heritable CLP in these multigenerational families, 2) characterizing the pathogenesis of the disorder and, 3) providing specific counseling information for families at risk for CLP. Information about heritable CLP may also lead to an understanding of the etiologic mechanisms involved in sporadic nonsyndromic CLP and other disorders resulting from abnormalities of embryogenesis.