Background
Cerebral deposition of amyloid beta peptide is an early and critical feature of Alzheimers disease and a frequent complication of Down syndrome. Amyloid beta peptide is generated by proteolytic cleavage of amyloid precursor protein by 2 proteases, one of which is the protein encoded by this gene. This gene localizes to the Down critical region of chromosome 21. The encoded protein, a member of the peptidase A1 protein family, is a type I integral membrane glycoprotein and aspartic protease. Three transcript variants encoding different isoforms have been described for this gene.