Heterozygous gain-of-function missense mutations in ABL1 have been reported to cause congenital heart defect and skeletal malformation syndrome (CHDSKM; Figure 2E, blue variants) (Wang et al., 2017; Chen et al., 2020; Blakes et al., 2021). The gene discussed is ABL1; the disease is congenital heart defects and skeletal malformations syndrome.