FBN1 and Marfan syndrome: The complexity of MFS clinical picture and its unpredictable course were extensively studied in the last decades, especially trying to elucidate the genotype-phenotype correlations of MFS and Marfan-like habitus. Mutations of FBN1 gene, encoding fibrillin-1, represent the most common genetic event associated with Marfan-like spectrum since a FBN1 mutations can be identified in 91–95% of subjects with classic MFS [16,17].