title: DNA repair/replication transcripts are down regulated in patients with Fragile X Syndrome.
abstract: BACKGROUND
  Fragile X Syndrome (FXS) and its associated disorders are caused by the expansion of the CGG repeat in the 5' untranslated region of the fragile X mental retardation 1 (FMR1) gene, with disease classification based on the number of CGG repeats. The mechanisms of repeat expansion are dependent on the presence of cis elements and the absence of trans factors both of which are not mutually exclusive and contribute to repeat instability. Expansions associated with trans factors are due to the haploinsuffient or reduced expression of several DNA repair/metabolizing proteins. The reduction of expression in trans factors has been primarily conducted in animal models without substantial examination of many of these expansion mechanisms and trans factors in humans.
  
  
  RESULTS
  To understand the trans factors and pathways associated with trinucleotide repeat expansion we have analyzed two microarray datasets which characterized the transcript expression in patients with FXS and in controls.
  
  
  CONCLUSIONS
  We observed significant down regulation of DNA damage/repair pathway transcripts. This observation was consistent in both datasets, which used different populations. Within these datasets, several transcripts overlapped in the direction of association and fold change. Further characterization of these genes will be critical to understand their role in trinucleotide repeat instability in FXS.
authors.affiliation: Center for Research on Genomics and Global Health, National Human Genome Research Institute, National Institutes of Health, 12 South Dr. MSC 5635, Bethesda, MD 20892, USA.
authors.forename: Huichun
authors.initials: H
authors.lastname: Xu
authors.forename: Mónica A
authors.initials: MA
authors.lastname: Rosales-Reynoso
authors.forename: Patricio
authors.initials: P
authors.lastname: Barros-Núñez
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Peprah
mesh_terms: D001321:Autistic Disorder / Q000235:genetics; D016000:Cluster Analysis; D004249:DNA Damage; D004260:DNA Repair; D004261:DNA Replication; D015536:Down-Regulation; D051860:Fragile X Messenger Ribonucleoprotein 1 / Q000235:genetics* / Q000378:metabolism; D005600:Fragile X Syndrome / Q000235:genetics*; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D015894:Genome, Human; D006801:Humans; D008297:Male; D020411:Oligonucleotide Array Sequence Analysis; D014158:Transcription, Genetic; D019680:Trinucleotide Repeat Expansion
chemical_list: D051860:Fragile X Messenger Ribonucleoprotein 1