title: [Cell-cycle negative regulatory gene ANA is over-expressed in the brain tissues of patients with Down syndrome].
abstract: OBJECTIVE
  To investigate the expression level of genes located in chromosome 21 in the brain tissues of Down syndrome(DS).
  
  
  METHODS
  An optimized semi-quantitative RT-PCR method was used to evaluate the expression levels of seven genes encoded in chromosome 21 in fetal cortex brain and cerebellum of DS and the control at the end of 20 weeks of gestation. B2M was used as internal reference to normalize cell loss.
  
  
  RESULTS
  The expression levels of 6 genes in cortex and cerebellum, including DYRK1A, SYNJ1, PCP4, C21orf5, C21orf2 and C21orf106, were comparable between DS and the control. ANA, a cell-cycle negative regulatory gene, was over-expressed dramatically in the cortex but not in the cerebellum of DS.
  
  
  CONCLUSIONS
  Over-expression of ANA may contribute to the reduction of neuronal density in DS brain.
authors.affiliation: Central Laboratory, Peking University People's Hospital, Beijing 100044, China. hexiangjun@hotmail.com
authors.forename: Xiang-jun
authors.initials: XJ
authors.lastname: He
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhang
authors.forename: Li-ping
authors.initials: LP
authors.lastname: Ma
authors.forename: Li-jun
authors.initials: LJ
authors.lastname: Yang
authors.forename: Huan
authors.initials: H
authors.lastname: Shen
authors.forename: Jing-zhu
authors.initials: JZ
authors.lastname: Guo
mesh_terms: D001921:Brain / Q000196:embryology / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000235:genetics*; D002531:Cerebellum / Q000196:embryology / Q000378:metabolism; D002540:Cerebral Cortex / Q000196:embryology / Q000378:metabolism; D002891:Chromosomes, Human, Pair 21 / Q000235:genetics*; D004314:Down Syndrome / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D018797:Cell Cycle Proteins; D012333:RNA, Messenger