title: Downregulation of TOMM40 expression in the blood of Alzheimer disease subjects compared with matched controls.
abstract: Translocase of outer mitochondrial membrane 40 homolog (TOMM40) gene has been reported in several GWAS to be associated with Alzheimer disease (AD). Gene expression studies thus far only showed TOMM40 differential expression in one study on brain cortex and not in peripheral blood. We studied the gene expression profiles of AD blood versus controls in an Asian population in Singapore. In this first analysis we focused on genes that have been previously reported on GWAS. We found TOMM40 to be significantly down-regulated in blood samples of AD in one discovery and two validation sets, totalling 45 subjects (mean age 76.90, SD 6.46) and 45 controls (mean age 76.23, SD 5.09), matched for ethnicity and gender. The function of TOMM40 is not yet fully characterized but is believed to be involved in import and trafficking of protein into mitochondria. Therefore TOMM40 downregulation, found in the brain in severe AD and in our blood profile, may be a potential marker for AD, disease severity or progression and merit further investigation.
authors.forename: Tih-Shih
authors.initials: TS
authors.lastname: Lee
authors.forename: Liang
authors.initials: L
authors.lastname: Goh
authors.forename: Mei Sian
authors.initials: MS
authors.lastname: Chong
authors.forename: Sze Ming
authors.initials: SM
authors.lastname: Chua
authors.forename: Geng Bo
authors.initials: GB
authors.lastname: Chen
authors.forename: Lei
authors.initials: L
authors.lastname: Feng
authors.forename: Wee Shiong
authors.initials: WS
authors.lastname: Lim
authors.forename: Mark
authors.initials: M
authors.lastname: Chan
authors.forename: Tze Pin
authors.initials: TP
authors.lastname: Ng
authors.forename: K Ranga
authors.initials: KR
authors.lastname: Krishnan
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000097:blood* / Q000208:ethnology / Q000235:genetics / Q000473:pathology; D001921:Brain / Q000378:metabolism; D016022:Case-Control Studies; D015536:Down-Regulation / Q000235:genetics; D005260:Female; D056726:Genetic Association Studies; D006801:Humans; D008297:Male; D026901:Membrane Transport Proteins / Q000097:blood* / Q000235:genetics; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D011569:Psychiatric Status Rating Scales; D012333:RNA, Messenger / Q000097:blood; D012846:Singapore / Q000208:ethnology
chemical_list: D026901:Membrane Transport Proteins; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D012333:RNA, Messenger; C400783:TOMM40 protein, human