Interestingly, heterozygous SMAD6 variants have also been reported on patients with congenital heart disease (CHD), bicuspid aortic valve (BAV), craniosynostosis (CS), or intellectual disability (ID; Calpena et al., 2020; Gillis et al., 2017; Jin et al., 2017; Lelieveld et al., 2016). The gene discussed is SMAD6; the disease is Intellectual disability.