MMP2 and Osteolysis: Also, autosomal recessive inactivating mutations of the MMP2 gene (MMP-2 deficiency) predispose to congenital heart defects, such as transposition of the great arteries to bicuspid aortic valve and septal defects in the atria and ventricles11 as well as to a multi-centric osteolysis and arthritis syndrome (MONA; OMIM #259600)12,14 – characterized by progressive bone demineralization, destruction of cartilage in joints and abnormal long bone and craniofacial development15.