title: Gene expression variation increase in trisomy 21 tissues.
abstract: Congenital development disorders with variable severity occur in trisomy 21. However, how these phenotypic abnormalities develop with variations remains elusive. We hypothesize that the differences in euploid gene expression variation among trisomy 21 tissues are caused by the presence of an extra copy of chromosome 21 and may contribute to the phenotypic variations in Down syndrome. We used DNA microarray to measure the differences in gene expression variance between four human trisomy 21 and six euploid amniocytes. The three publicly available data sets of fetal brains, adult brains, and fetal hearts were also analyzed. The numbers of euploid genes with greater variance were significantly higher in all four kinds of trisomy 21 tissues (p<0.01) than in the corresponding euploid tissues. Seventeen euploid genes with significantly different variance between trisomy 21 and euploid amniocytes were found using the F test. In summary, there is a set of euploid genes that shows greater variance of expression in human trisomy 21 tissues than in euploid tissues. This change may contribute to producing the variable phenotypic abnormalities observed in Down syndrome.
authors.affiliation: Department of Obstetrics and Gynecology, Cathay General Hospital, Taipei, Taiwan.
authors.forename: Ching Yu
authors.initials: CY
authors.lastname: Chou
authors.forename: Li Yu
authors.initials: LY
authors.lastname: Liu
authors.forename: Chien Yu
authors.initials: CY
authors.lastname: Chen
authors.forename: Cheng Hsien
authors.initials: CH
authors.lastname: Tsai
authors.forename: Hsiao Lin
authors.initials: HL
authors.lastname: Hwa
authors.forename: Li Yun
authors.initials: LY
authors.lastname: Chang
authors.forename: Yi Shing
authors.initials: YS
authors.lastname: Lin
authors.forename: Fon Jou
authors.initials: FJ
authors.lastname: Hsieh
mesh_terms: D000653:Amniotic Fluid / Q000166:cytology / Q000378:metabolism; D002877:Chromosomes, Human / Q000235:genetics; D004314:Down Syndrome / Q000235:genetics*; D005786:Gene Expression Regulation / Q000235:genetics*; D014644:Genetic Variation / Q000235:genetics*; D006801:Humans