_:vb50940767 . _:vb50940767 . _:vb50940767 "url:https://www.ncbi.nlm.nih.gov/pubmed/22275001"^^ . _:vb50940767 "A bicuspid aortic valve disease that has_material_basis_in heterozygous mutation in the SMAD6 gene on chromosome 15q22."^^ . _:vb50940767 . _:vb50940767 . _:vb50940767 .