FBN1 and Mitral regurgitation: P4 was also diagnosed to have Marfan syndrome due to carrying a known disease causing mutation in FBN1 gene (NM_000138, heterozygous c.7240C > T/p.Arg2414Ter, HGMD CM020137), having typical features (congenital heart disease with VSD with mitral valve regurgitation, and arachnodactyly), and positive family history (mother and maternal grandmother) (Loeys et al., 2010).