title: The lack of associations between alleles at the hypoxia-inducible factor 1A C1772T loci and responses to acute hypoxia.
abstract: OBJECTIVE
  The aim of this study was to investigate the associations between alleles of the hypoxia-inducible factor 1A (HIF1A) C1772T polymorphism and several physiological responses to hypoxia, including the hypoxic ventilatory response (HVR), and serum erythropoietin (EPO), arterial oxygen saturation (Sao2), and acute mountain sickness (AMS) responses during 8 hours of exposure to normobaric hypoxia.
  
  
  METHODS
  A total of 76 males participated in the study; 52 participants completed an 8-hour exposure to 12.7% oxygen, during which time Sao2, EPO concentrations, and AMS scores were measured, while 62 individuals took part in an HVR trial (in total 38 individuals completed both protocols). DNA was obtained from leukocytes, and a 346-bp fragment of the HIF1A gene containing the C1772T polymorphism was amplified using polymerase chain reaction. Fragments were sequenced to reveal individual genotypes, and the associations between HIF1A genotype and EPO, Sao2, AMS responses to hypoxia and HVR were examined.
  
  
  RESULTS
  The magnitude of the hypoxic responses was highly variable between individuals. The increase in participants' EPO responses ranged from 89% to 388% of baseline values following hypoxia, while Sao2 values during the exposure ranged from 71% to 89%. The HVR ranged from -0.04 to +2.18 L x min(-1) x Sao2 %(-1) among participants. No significant differences in EPO, Sao2, AMS, or HVR results were observed between the HIF1A CC genotype and the combined CT/TT genotype group.
  
  
  CONCLUSIONS
  In this study, the HIF1A C1772T polymorphism does not appear to influence EPO, Sao2, or AMS responses during acute hypoxic exposure, or the magnitude of the HVR.
authors.affiliation: School of Science and Technology, Nottingham Trent University, Nottingham, England. philiphennis@hotmail.com
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Hennis
authors.forename: Christopher
authors.initials: C
authors.lastname: Bussell
authors.forename: Mark G
authors.initials: MG
authors.lastname: Darlison
mesh_terms: D000328:Adult; D000483:Alleles; D000532:Altitude Sickness / Q000235:genetics* / Q000503:physiopathology*; D000704:Analysis of Variance; D004921:Erythropoietin / Q000097:blood; D006801:Humans; D000860:Hypoxia / Q000235:genetics* / Q000503:physiopathology*; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics; D008297:Male; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D012123:Pulmonary Ventilation / Q000235:genetics / Q000502:physiology; D011795:Surveys and Questionnaires; D055815:Young Adult
chemical_list: D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D004921:Erythropoietin