MAMDC2 is a 686 amino acid secreted protein that localizes to extracellular matrix. Containing four MAM domains and existing as two alternatively spliced isoforms, MAMDC2 is encoded by a gene located on human chromosome 9q21.11. Chromosome 9 consists of about 145 million bases, 4% of the human genome and encodes nearly 900 genes. Considered to play a role in gender determination, deletion of the distal portion of 9p can lead to development of male to female sex reversal, the phenotype of a female with a male X,Y genotype. Hereditary hemorrhagic telangiectasia, Familial dysautonomia and certain leukemias are also associated with chromosome 9.