A single heterozygous nucleotide substitution displays two different altered mechanisms in the FBN1 gene of five Italian Marfan patients

The Fibrillin-1 gene (FBN1; chromosome 15q21.1) encodes a major glycoprotein component of the extracellular matrix. Mutations in FBN1, TGFBR1, TGFBR2 are known to cause Marfan syndrome (MIM 154700), a pleiotropic disorder. In the present study, we describe five novel missense FBN1 mutations in five Marfan patients that have the peculiarity to activate two contemporary mutational mechanisms: a missense mutation and exon skipping.