ARID1B and hypoplastic left heart syndrome: In a larger fetal cohort of 44 fetuses with Coffin-Siris associated genes, 80% of fetuses with ARID1A pathogenic variant had a cardiovascular anomaly, and 33% of fetuses with SMARCB1 pathogenic variant had cardiovascular anomalies.11 Only 1 fetus with a ARID1A pathogenic variant had a hypoplastic right heart and 2 had a hypoplastic left heart syndrome.11 The research group also reported hypoplastic left heart syndrome in 1 fetus with ARID1B and 2 fetuses with SMARCA4 pathogenic variants.11 Also a case with prenatal CSS related to SMARCC2 with tetralogy of Fallot has been reported.14