Down Syndrome (DS) Cell Adhesion Molecules (DSCAMs) represent a small group of transmembrane proteins of the immunoglobulin superfamily comprising, in vertebrates, DSCAM and its paralogue DSCAM-like 1 (DSCAML1) (Yamakawa et al., 1998; Agarwala et al., 2001). This evidence concerns the gene DSCAM and Down syndrome.