Clinical and Molecular Studies of Malformations

该实验室使用转化研究方法来研究人类畸形。在临床竞技场，我们操作几个临床研究方案，以评估严重程度的范围，畸形谱，和自然史的多效性发育异常。我们使用包括病史和体格检查、影像学研究（包括X线摄影、超声和断层扫描）以及EEG、肺功能测试等在内的临床评价来表征功能和结构异常。在选定的情况下，我们也进行手术治疗，如果他们提供临床效益，可以提高我们对所研究疾病的理解。此外，我们在再洗礼教派（阿米什人和门诺派）中进行实地考察，以研究该人群中流行的人类遗传疾病。最后，我们与NCBI合作开发了再洗礼派家谱数据库，这是一个遗传研究的研究资源，包括超过40万个条目。我们目前正在研究的一些疾病包括Pallister-Hall、Greig头多并指、McKusick考夫曼、Proteus、Bardet-Biedl、伦茨小眼症和眼面心牙综合征。 我们使用现代分子生物学的工具来确定这些疾病的分子发病机制。这些包括定位克隆、微阵列表达和微阵列CGH分析、评估细胞生物学功能和基因产物异常的细胞和组织培养研究，以及人类遗传疾病动物模型（小鼠和斑马鱼）的创建和分析。 利用这些技术，我们已经阐明了Pallister-Hall，McKusick-Kaufman，伦茨小眼症和眼面心牙综合征的病因。此外，我们已经证明了Pallister-Hall综合征的功能缺陷，通过比较该疾病（GLI 3）的致病基因与其果蝇同源基因（cubitus interruptus）的功能，并将这些功能与150多名患者的突变相关联。在此过程中，我们确定Pallister Hall综合征的发病机制与Greig头多并指综合征不同。我们还在临床上重新定义了变形综合征，这是一种具有肿瘤易感性的马赛克过度生长疾病。我们通过对35例患者进行评估，并对文献中报告的所有病例进行详尽的调查。这使我们能够建立新的临床诊断标准，这种疾病和描绘一个新的疾病实体，偏侧增生-多发性脂肪增多症综合征。在我们对伦茨小眼综合征的研究中，我们确定这种疾病实际上是两种不同的X连锁疾病的合并，其中一种伦茨与眼面心齿综合征是等位基因，这两种疾病都是由BCOR基因突变引起的。 最后，我们使用动物模型来研究两种疾病，阿米什小头畸形综合征，我们确定这是由DNC基因突变引起的，和格雷格头多并指综合征的表型。对于阿米什人的小头畸形，我们利用转基因技术建立了一个该疾病的小鼠基因敲除模型，并正在利用遗传和生化分析研究该疾病的病理生理学。我们还进行了位置克隆分析的格雷格头多并趾表型的小鼠使用一个零星的突变体在一个大型育种设施。这种疾病现在已经被映射到500 KB的间隔，候选基因正在测序中。

The laboratory uses a translational research approach to study human malformations. In the clinical arena, we operate several clinical research protocols to assess the range of severity, spectrum of malformations, and natural history of pleiotropic developmental anomalies. We use clinical evaluations that include history and physical examination, imaging studies including radiography, ultrasound, and tomography, as well as EEG, pulmonary function testing, etc. to characterize functional and structural anomalies. In selected cases we also perform surgical treatments if they offer clinical benefit and can advance our understanding of the disease under study. In addition, we perform fieldwork among the Anabaptist sects (Amish and Mennonites) to study human genetic diseases prevalent in that population. Finally, we collaborate with NCBI to develop the Anabaptist Genealogy Database, which is a research resource for genetic research that includes over 400,000 entries. Some of the disorders that we are currently studying include Pallister-Hall, Greig cephalopolysyndactyly, McKusick Kaufman, Proteus, Bardet-Biedl, Lenz microphthalmia, and Oculofaciocardiodental syndromes. We use the tools of modern molecular biology to determine the molecular pathogenesis of these disorders. These include positional cloning, microarray expression and microarray CGH analysis, cell and tissue culture studies to assess cell biologic functions and abnormalities of gene products, and the creation and analysis of animal models of human genetic disease (mouse and zebrafish). Using these techniques we have elucidated the etiology of Pallister-Hall, McKusick-Kaufman, Lenz microphthalmia and Oculofaciocardiodental syndromes. In addition, we have demonstrated the functional defect of Pallister-Hall syndrome by comparing the function of the causative gene in that disorder (GLI3) to its Drosophila homologue (cubitus interruptus) and correlating those functions with mutations in over 150 patients. In so doing, we have determined that the mechanism of Pallister Hall syndrome is distinct from that of Greig cephalopolysyndactyly syndrome. We have also clinically redefined the Proteus syndrome, a disorder of mosaic overgrowth with tumor susceptibility. We did this through evaluating a series of 35 patients and an exhaustive survey of all cases reported in the literature. This allowed us to establish new clinical diagnostic criteria for this disorder and delineate a novel disease entity, the hemihyperplasia-multiple lipomatosis syndrome. In our studies of Lenz microphthalmia syndrome we determined that this disorder is actually an amalgamation of two distinct X-linked diseases and that one form of Lenz is allelic to Oculofaciocardiodental syndrome and that both of these diseases are caused by mutations in the BCOR gene. Finally, we are using animal models to study two disorders, Amish microcephaly syndrome, which we determined to be caused by mutations in the DNC gene, and a phenocopy of Greig cephalopolysyndactyly syndrome. For Amish microcephaly, we have created a mouse knockout model of that disease using transgenic technology and are studying the pathophysiology of that disorder using genetic and biochemical analysis. We are also performing a positional cloning analysis of the Greig cephalopolysyndactyly phenotype in the mouse using a sporadic mutant identified at a large breeding facility. This disorder has now been mapped to a 500 KB interval and candidate genes are being sequenced.