title: Reduced levels of oestrogen receptor beta mRNA in Swedish patients with chronic fatigue syndrome.
abstract: BACKGROUND
  Chronic fatigue syndrome (CFS) is an illness with unknown aetiology and pathophysiology. The difference in incidence by sex observed for CFS indicates a role for oestrogen and oestrogen receptors in disease development. Furthermore, an immunomediated pathogenesis has been suggested for CFS, providing an additional connection to oestrogen, which displays immunomodular functions.
  
  
  OBJECTIVE
  To investigate a possible association of oestrogen receptor (ER) mRNAs and two ERbeta single-nucleotide polymorphisms (SNPs) with CFS.
  
  
  METHODS
  Messenger RNA levels of ERalpha, ERbeta wt and ERbeta cx were investigated in peripheral blood mononuclear cells from 30 patients with CFS and 36 healthy controls by quantitative real-time polymerase chain reaction. Two ERbeta SNPs were scored in the same material.
  
  
  RESULTS
  The CFS group showed significantly lower mRNA expression levels of ERbeta wt compared with the healthy control group. No differences were observed for ERalpha or ERbeta cx between patients and controls. There were no significant differences in frequency for the investigated ERbeta SNPs between cases and controls.
  
  
  CONCLUSIONS
  The reduced ERbeta wt expression level observed in this study is consistent with an immune-mediated pathogenesis of CFS. Additionally, the observation that ERbeta wt expression is decreased in CFS could provide an entry point to identify interesting, potentially disease-causing, candidate molecules for further study. A possible connection between oestrogen, oestrogen receptors and CFS should be evaluated further.
authors.affiliation: Department of Laboratory Medicine, Division of Clinical Bacteriology, Karolinska Institutet, Karolinska University Hospital, Huddinge, Stockholm, Sweden.
authors.forename: Hanna
authors.initials: H
authors.lastname: Gräns
authors.forename: Maria
authors.initials: M
authors.lastname: Nilsson
authors.forename: Karin
authors.initials: K
authors.lastname: Dahlman-Wright
authors.forename: Birgitta
authors.initials: B
authors.lastname: Evengård
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D047628:Estrogen Receptor alpha / Q000096:biosynthesis / Q000097:blood / Q000235:genetics; D047629:Estrogen Receptor beta / Q000096:biosynthesis* / Q000097:blood / Q000235:genetics; D015673:Fatigue Syndrome, Chronic / Q000097:blood* / Q000235:genetics; D005260:Female; D015870:Gene Expression; D006801:Humans; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
chemical_list: D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D012333:RNA, Messenger