Definition of MASS syndrome

MASS syndrome: 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 FBN1, the fibrillin 1 gene. The same gene as is mutated in Marfan syndrome.