ATP-binding cassette transporter A7 (ABCA7), located on chromosome 19, is a recently discovered potential risk factor for AD. ABCA7 protein, which is highly homologous to ABCA1, may be involved in the synthesis and transport of high-density lipoprotein cholesterol and generate phospholipid and cholesterol efflux from the cells. It can also play a key role in sterol homeostasis and in the host defense system.171,172 The two variants (rs3752246 and rs3764650) in ABCA7 have been suggested to be associated with LOAD.171 Rs3764650 is located in intron 13, and rs3752246 is a missense mutation in exon 32 (Gly1527 Ala).171 Recent findings have revealed an additional SNP (rs115550680) that might be involved in LOAD in African-Americans. Since ABCA7 plays a role in the lipid metabolism as well as in APP transport, mutations in ABCA7 gene might be involved in LOAD.173
