FBN1 and Marfan syndrome: Given the relatively high minor allele frequencies for these SNPs (9.56–9.97%), as well as the well-defined role of FBN1 in the pathogenesis of connective tissues disorders including Marfan syndrome, we hypothesize that mutations within this linkage group may account for a non-trivial portion of nonsyndromic thoracic aortic aneurysms and dissections, particularly those within the context of positive family history.