OCIAD2 Background Information OCIAD2 (OCIA domain containing 2) is a 154 amino acid protein that localizes to endosomes and contains one OCIA domain. OCIAD2 exists as multiple alternative spliced isoforms and is encoded by a gene which localizes to human chromosome 4. Representing approximately 6% of the human genome, chromosome 4 contains nearly 900 genes, one of which is the Huntingtin gene, which is found to encode an expanded glutamine tract in cases of Huntington's disease. FGFR-3 is also encoded by a gene that localizes to chromosome 4 and has been associated with thanatophoric dwarfism, achondroplasia, Muenke syndrome and bladder cancer. Defects in chromosome 4 are also tied to Ellis-van Creveld syndrome, methylmalonic acidemia and polycystic kidney disease.
