title: Epsilon globin gene expression in developing human fetal tissues.
abstract: OBJECTIVE
  The discovery of free fetal DNA in plasma of pregnant women has opened a new avenue for non-invasive prenatal diagnosis. We hypothesized that epsilon (ɛ)-globin gene expression could serve as a positive control for the presence of fetal nucleic acid.
  
  
  METHODS
  We measured ɛ-globin mRNA in human fetal tissues and compared concentrations with that measured in adult non-pregnant and pregnant samples. Total RNA was isolated from fetal marrow, liver, blood, and placenta (10-24 weeks gestation), from adult peripheral blood mononuclear cells, and from maternal plasma. RNA was reverse transcribed and quantitative polymerase chain reaction performed for ɛ-globin expression.
  
  
  RESULTS
  ɛ-globin gene expression was detected in all fetal samples, was detected in plasma of pregnant women, but was negligible in non-pregnant samples. Relative ɛ-globin gene expression was significantly greater in fetal blood compared to fetal liver, and was minimally expressed in placenta. ɛ-globin gene expression decreased at the highest gestational ages in fetal blood, while expression was greatest at 15-19 weeks in fetal marrow.
  
  
  CONCLUSIONS
  Fetal ɛ-globin gene expression is significantly greater than adult expression and is increased in maternal plasma compared to non-pregnant samples. ɛ-globin gene expression might serve as a positive control when determining the presence of fetal nucleic acid in total nucleic acid isolated from maternal plasma.
authors.affiliation: Department of Pediatrics, University of New Mexico, Albuquerque, New Mexico.
authors.forename: S
authors.initials: S
authors.lastname: McConaghy
authors.affiliation: St. Joseph's Hospital, Phoenix, AZ, USA.
authors.forename: V
authors.initials: V
authors.lastname: Manuel
authors.affiliation: Department of Pediatrics, University of New Mexico, Albuquerque, New Mexico.
authors.forename: S
authors.initials: S
authors.lastname: Nagji
authors.affiliation: Department of Pediatrics, University of New Mexico, Albuquerque, New Mexico.
authors.forename: R K
authors.initials: RK
authors.lastname: Ohls
mesh_terms: D015415:Biomarkers / Q000032:analysis / Q000097:blood; D005260:Female; D005333:Fetus / Q000196:embryology / Q000378:metabolism*; D020869:Gene Expression Profiling; D005865:Gestational Age; D006801:Humans; D008099:Liver / Q000378:metabolism; D009928:Organ Specificity; D010920:Placenta / Q000378:metabolism; D011247:Pregnancy; D011296:Prenatal Diagnosis; D012333:RNA, Messenger / Q000032:analysis* / Q000097:blood*; D012015:Reference Standards; D055547:epsilon-Globins / Q000235:genetics*
chemical_list: D015415:Biomarkers; D012333:RNA, Messenger; D055547:epsilon-Globins
keywords: Epsilon globin; fetal tissues; noninvasive; nucleic acid; prenatal diagnosis