Fig. 2: Analysis of SMC3 variants in patients with isolated congenital heart disease.

a Statistical overview of the types of congenital heart disease (CHD) in Cornelia de Lange syndrome (CdLS) patients with SMC3 mutations. The inner layer represents the pathological categorization of CHD types. The outer layer shows CHD types. The digit in brackets indicates the number of CdLS patients. b Sanger sequencing chromatograms of three SMC3 coding variants (R221T, T857S, and Y434C). The SMC3 variant (Y434C) was screened by multiplex PCR-targeting sequencing and verified by Sanger sequencing. The black arrows in the upper panels indicate variant sites. The lower panels show wild-type (WT) sequences. c General information on the ten coding variants. Red markings represent increased pathogenicity. See Supplementary Table 3 for further details. Categorical predictions from each algorithm. ExAC contains high-quality exome sequencing data for 60,706 individuals from different ancestries. The values represent the frequencies of variant occurrence. SIFT, “T”=tolerated, “D”=damaging. The numbers represent the probabilities of similarity between the variant and the actual variant as calculated using the SIFT algorithm, with values less than 0.05 indicating significant differences. PolyPhen2 HDIV, “B”=benign, “P”=possibly damaging, “D”=likely damaging. Numbers represent the probabilities that the variant changes the protein structure and function as calculated using the HumDiv algorithm. CADD, the numbers represent the score of the deleteriousness of the variant based on several factors, including the polymorphism of the allele and the pathogenicity of the variant, with a higher value representing a greater probability that the variant is “deleterious”. A phred score >20 is generally considered “deleterious”. d The effects of variants on SMC3 expression. The level of SMC3 in SMC3-knockdown (KD) AC16 cells overexpressing SMC3-WT was higher than that in cells overexpressing the variant. e Evolutionary tree of SMC3 in eleven species. Each node represents a taxon. The numbers indicate the reliability of the branch, and a larger value indicates greater reliability. The branch lengths represent the genetic variability of the sequence and are calculated based on a distance scale. f Protein domain plot of SMC3 and the site (top panel) and conserved region (bottom panel) of ten coding variants. The color of each arrow pointing to the variant represents the variant type. All identified SMC3 variants are indicated at the corresponding positions. TOF tetralogy of Fallot, PDA patent ductus arteriosus, PS pulmonary stenosis, BAV mitral and aortic valve, AS aortic stenosis, ASD atrial septal defect, PPS peripheral pulmonary stenosis, PAH pulmonary arterial hypertension, NC normal control cells transfected with a blank vector, ExAC exome aggregation consortium, SIFT Sorting Intolerant From Tolerant, Polyphen2 polymorphism phenotyping v2, HDIV HumDiv model, CADD combined annotation-dependent depletion, WES whole-exon sequencing.