Identification of Two Novel Mutations from Congenital Heart Defects and Related Cellular Function

Abstract

ObjectiveCongenital heart defects (CHD) represent the most common congenital anomaly in newborns. The causes of CHD are complex, and are not fully understood. A number of genetic studies have linked gene mutations to cardiac abnormalities. In this study, we found a child who was diagnosed as having a complex including complete endocardial cushion defect, patent ductus arteriosus, secondary atrial septal defect, severe pulmonary hypertension, and polydactyly, we aimed to identify potential pathogenic mutations from this complex.MethodsThe whole blood was collected and genomic DNA was extracted to identify mutations by whole exome sequencing (WES). The CRISPR/Cas9 system was used to generate human pluripotent stem cell with mutations (hPSC‐Mut) separately. As pluripotency markers, Oct4, Nanog, Klf4, SSEA4 were tested in hPSC‐Mut cell, by the methods of Immunofluorescence, Real‐Time PCR, Western Blot. The hPSC‐Mut cell was then inducted and differentiated into cardiomyocytes (CM‐Mut), The differentiation efficiency and contraction of CM‐Mut was detected in 0d, 2d, 4d, 8d, 13d.ResultTwo heterozygous mutations, LTBP2 (c.2206G>A), TCTN3 (c.1268G>A) were identified via WES and analysed by bioinformatics. The hPSC‐LT/TC stable cell line was constructed, inducted and differentiated into CM‐LT/TC. Compare to the wild type, there were no significant differences in cell pluripotency and differentiation efficiency. The cell contraction was observed in the 8th day and lasted to the 13rd day, the contraction of CM‐LT was faster and CM‐LT was slower than wild type cell line.ConclusionTwo heterozygous mutations LTBP2 (c.2206G>A) and CTN3 (c.1268G>A) with alteration of the contraction of CM‐LT/LT cell were found to be pathogenic in complex CHD.Support or Funding InformationNational Natural Science Foundation of China (81870288, 81641017), National Central Grants for Research Institute (2017NL31001), Binhai New Area Health Bureau ( 2016BWKZ 003).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

A splice site variant inTCTN3underlies an atypical form of orofaciodigital syndrome IV

“…Previously, a compound heterozygous and five homozygous TCTN3 variants with OFD4 have been reported in families of different ancestries (Al‐Dewik et al., 2019 ; Thomas et al., 2012 ; Yadava & Ashkinadze, 2019 ). Variants in TCTN3 have also been reported to be involved in the etiology of Joubert syndrome and congenital heart defects (Chen et al., 2019 ; Huppke et al., 2015 ). Frameshift and nonsense variants have been observed more often with OFD4, whereas missense variants are more closely associated with other disorders.…”