Definition of Syndrome, MASS

Syndrome, MASS: A heritable disorder of connective tissue characterized by involvement of the mitral valve, aorta, skeleton, and skin. Hence, the acronym MASS (Mitral valve, Aorta, Skeleton, Skin).

The MASS syndrome is due to a mutation in the fibrillin 1 gene FBN1, the same gene as is mutated in Marfan syndrome.