Jing Wang1, Jing Luo2, Qiuhong Chen3, Xi Wang4, Jiangyan He5, Wei Zhang4, Zhan Yin5, Fang Zheng2, Hong Pan4, Tengyan Li4, Qiyong Lou6, Binbin Wang7. 1. Department of Medical Genetics and Developmental Biology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China. 2. Center for Gene Diagnosis, Zhongnan Hospital, Wuhan University, Wuhan, Hubei 430071, China. 3. Cardiovascular Center, Qinghai High Altitude Medical Research Institute, Xining 810012, China. 4. Center for Genetics, National Research Institute for Family Planning, Beijing 100081, China. 5. Key Laboratory of Aquatic Biodiversity and Conservation of the Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China. 6. Key Laboratory of Aquatic Biodiversity and Conservation of the Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China. Electronic address: louqiyong@ihb.ac.cn. 7. Center for Genetics, National Research Institute for Family Planning, Beijing 100081, China. Electronic address: wbbahu@163.com.
Abstract
BACKGROUND: Atrial septal defect (ASD) is one of the most common cardiac malformations worldwide. Several genes have been identified so far, which can merely explain small proportion of all the cases, therefore, it is anticipated that there are additional genes causing ASD. The aims of this study were to identify the causal gene of ostium secundum atrial septal defect (ASDII) in a Chinese family. METHODS: Whole exome sequencing was performed in three affected members and one control in the ASDII family. We screened mutations of LBX2 in 300 unrelated ASD patients and validated in 400 normal controls by Sanger sequencing. LBX2 knockout zebrafish was generated by CRISPR/Cas9 to detect whether lbx2 deficiency influenced cardiac development. RESULTS: A rare missense mutation in LBX2 (c.A403G: p.K135E) was identified as the pathogenic cause of ASD. Subsequent mutation screening revealed two missense variants in 3 of 300 sporadic patients. We observed expanded size of atrium and ventricle in LBX2 knockout zebrafish through hematoxylin-eosin staining, more incompact distribution of cardiac myocytes was also discovered in homozygote compared with in wildtype. Furthermore, we performed in situ hybridization of crip2 gene to trace the cardiac neural crest cells in the embryo stage and found that the migration of neural crest cells was obviously delayed in the homozygotes. CONCLUSIONS: We identified LBX2 for the first time as a pathogenic gene of ASDII. LBX2 deficiency may cause abnormal development of heart through influencing the migration of neural crest cells and affect the process of cardiac septation.
BACKGROUND:Atrial septal defect (ASD) is one of the most common cardiac malformations worldwide. Several genes have been identified so far, which can merely explain small proportion of all the cases, therefore, it is anticipated that there are additional genes causing ASD. The aims of this study were to identify the causal gene of ostium secundum atrial septal defect (ASDII) in a Chinese family. METHODS: Whole exome sequencing was performed in three affected members and one control in the ASDII family. We screened mutations of LBX2 in 300 unrelated ASDpatients and validated in 400 normal controls by Sanger sequencing. LBX2 knockout zebrafish was generated by CRISPR/Cas9 to detect whether lbx2 deficiency influenced cardiac development. RESULTS: A rare missense mutation in LBX2 (c.A403G: p.K135E) was identified as the pathogenic cause of ASD. Subsequent mutation screening revealed two missense variants in 3 of 300 sporadic patients. We observed expanded size of atrium and ventricle in LBX2 knockout zebrafish through hematoxylin-eosin staining, more incompact distribution of cardiac myocytes was also discovered in homozygote compared with in wildtype. Furthermore, we performed in situ hybridization of crip2 gene to trace the cardiac neural crest cells in the embryo stage and found that the migration of neural crest cells was obviously delayed in the homozygotes. CONCLUSIONS: We identified LBX2 for the first time as a pathogenic gene of ASDII. LBX2 deficiency may cause abnormal development of heart through influencing the migration of neural crest cells and affect the process of cardiac septation.
Authors: Yicheng Long; Taeyoung Hwang; Anne R Gooding; Karen J Goodrich; John L Rinn; Thomas R Cech Journal: Nat Genet Date: 2020-07-06 Impact factor: 38.330