基于全外显子组测序的肺静脉异位引流拷贝数变异研究

Copy Number Variations of Anomalous Pulmonary Venous Connection Based on Whole Exome Sequencing

目的探讨罕见拷贝数变异(copy number variations,CNVs)与肺静脉异位引流(anomalous pulmonary venous connection,APVC)的关联。方法采用病例-对照研究,对2012~2017年在中国医学科学院阜外医院治疗的144名肺静脉异位引流患儿进行全外显子组测序,同时以188名无心血管系统疾病的肥胖及正常儿童的全外显子组数据为对照进行CNVs鉴定和关联研究。结果在病例组和对照组中分别鉴定出1116个和1360个罕见CNVs。病例组所携带的CNVs平均长度为81.84 Kb,范围为1.0 kb到22.80 Mb,且鉴定出5个病例组独有的大片段CNVs(>2 Mb),而对照组的CNVs平均长度为66.26 kb,范围为1.0 kb-1.52Mb。其次,本研究鉴定出20个在病例组重复出现至少3次且未在对照组中出现的CNVs。其中,所覆盖的POU5F1基因和SLC35E2B基因参与左-右非对称分化的决定,且与已知先心病基因存在相互作用,提示它们可能参与APVC致病过程。此外,病例组相对富集的CNVs共覆盖41个已报道的先心病基因,集中富集于心脏发育和左-右非对称分化相关通路。结论罕见拷贝数变异及其覆盖的左-右非对称分化等心脏发育相关基因可能参与疾病的发生。

Objective This study is to explore the association between rare exonic copy number variations(CNVs)and anomalous pulmonary venous connection(APVC).Methods We performed whole exome sequencing(WES)for 144 patients with anomalous pulmonary venous connection recruited at Fuwai Hospital of the Chinese Academy of Medical Sciences from 2012 to 2017.CNVs identification and association analyses were performed using the WES data of these patients and 188 obese and normal children without cardiovascular disease as controls.Results 1116 and 1360 rare CNVs were identified in the case group and the control group,respectively.The average length of CNVs carried by the case group was 81.84 Kb,ranging from 1.0 kb to 22.80 Mb,and 5 large unique CNVs(>2 Mb)were identified in the case group.The average length of the control group was 66.26 kb,and the range was 1.0 kb-1.52 Mb.In addition,we identified 20 CNVs that recurred at least 3 times in the case group and did not appear in the control group.Among them,the covered POU5 F1 gene and SLC35 E2 B interact with known candidate genes for congenital heart defects and are involved in the determination of left-right asymmetry differentiation,suggesting that these two genes may be involved in the pathogenesis of APVC.In addition,pathway enrichment analysis of 41 reported congenital heart defects genes covered by relatively enriched CNVs in the cases revealed several significant pathways crucial for heart development and left-right asymmetry differentiation.Conclusion Rare exonic CNVs,especially CNVs covering cardiac development-related genes such as the developmenet of left-right asymmetry,are involved in the development of APVC.