QPRT and early-onset autosomal dominant Alzheimer disease: Most of these 25 genes are expressed in brain, among them several genes have been found to be involved in Alzheimer's disease, including SPN (sialophorin, also named as CD43), CORO1A (coronin, actin binding protein, 1A), QPRT (quinolinate phosphoribosyltransferase), MAZ (MYC-associated zinc finger protein), and MAPK3 (mitogen-activated protein kinase 3, also named as ERK1).