Fbn1C1041G/+ heterozygous mice, which contain a similar variant to the human FBN1 Cys1039Tyr pathogenic variant representing a common mechanism of disease for MFS with substitution of a cysteine in the calcium-binding EGF-like domain, develop typical skeletal and cardiovascular abnormalities though modest in severity and without clinical endpoints of lethality (9). This evidence concerns the gene FBN1 and Marfan syndrome.