Studying Pentalogy of Cantrell in Humans and Mice

坎特雷尔五联症(POC)是一种发育障碍，估计每100万活产中有1-5.5例发生，存活率为61%。该综合征包括五个特征：1)胸骨融合缺陷，通常导致心脏异位；2)横隔性疝气，使腹部器官伸入胸腔；3)腹壁变薄，通常导致脐膨出；4)心包缺失或缺陷；5)心脏结构和瓣膜缺陷，包括室间隔缺陷和主动脉出口移位至右室。我们的实验室已经培育出具有人类POC表型的非肌肉肌球蛋白2B重链(由Myh10基因编码)上单一氨基酸替代(R709C)的小鼠。小鼠模型的产生促使我们启动了一项人类临床研究，在该研究中，我们正在对POC患者及其父母进行全外显子组测序和全基因组测序，以确定POC的可能遗传病因。在过去的一年里，我们又增加了5个家庭到我们的研究中。目前在我们研究中的29名先证者在登记时年龄从1天到31岁不等，并表现出该疾病五个特征特征的不同亚组。最近，我们与USUHS的CHIRP设施合作，启动了我们的样本的全基因组测序(WGS)。这些样本目前正在进行生物信息学分析。WGS具有提供更好的外显子覆盖率、调用拷贝数变体(CNV)以及插入和缺失(INDel)的优点，并且可以提供有关感兴趣基因周围的非编码(潜在调节)区域的信息。WES和WGS的初步结果显示了一些感兴趣的候选基因，但在两到三个不相关的家系中没有一个是重复的。我们目前正在使用CRISPR基因组编辑在小鼠模型中测试它们的生物学意义。我们正在生成两个鼠标线。一个是PTPN11基因点突变，另一个是MTOR基因点突变。PTPN11和MTOR基因都参与了心脏发育的调控。

Pentalogy of Cantrell (POC) is a developmental disorder estimated to occur in 1-5.5 per 1 million live births with a 61% survival rate. The syndrome includes five features: 1) a defect in sternal fusion, often resulting in ectopia cordis, 2) a diaphragmatic hernia, allowing the abdominal organs to protrude into the thoracic cavity, 3) a weakened abdominal wall, often resulting in an omphalocele, 4) a missing or defective pericardium, and 5) structural and valvular defects in the heart, including ventricular septal defect and displacement of the aorta outlet to the right ventricle. Our laboratory has generated mice with a single amino acid substitution (R709C) in the non-muscle myosin 2B heavy chain (encoded by the Myh10 gene) which phenocopies human POC. Generation of the mouse model prompted us to initiate a clinical study in humans in which we are conducting whole exome sequencing as well as whole genomic sequencing of POC patients and their parents to determine a possible genetic etiology for POC. During the past year we have added 5 more families to our study. The 29 probands currently in our study range from 1 day to 31 years of age at time of enrollment and exhibit different subsets of the five characteristic features of the disorder. Recently we have initiated whole genome sequencing (WGS) of our samples in collaboration with the CHIRP facility at USUHS. The samples are presently undergoing bioinformatic analysis. WGS has the benefits of providing better coverage of exons, of calling copy number variants (CNVs) and insertions and deletions (indels), and can provide information about non-coding (potentially regulatory) regions around the genes of interest. Preliminary results from WES and WGS indicate some candidate genes of interest, however none of them is recurrent in two or three unrelated families. We are currently testing their biological significance in mouse models using CRISPR genome editing. We are generating two mouse lines. One with a point mutation in the PTPN11 gene, the other with a point mutation in the MTOR gene. Both PTPN11 and MTOR genes have been implicated in regulating cardiac development.