title: Effect of sex and haplotype on plasma tryptase levels in healthy adults.
abstract: BACKGROUND
  The total level of alpha-tryptase and ss-tryptase in serum or plasma is used as a clinical indicator of the mast cell burden.
  
  
  OBJECTIVE
  The effect of the tryptase haplotype and of sex on the total tryptase level of healthy individuals was determined.
  
  
  METHODS
  A novel hot-stop PCR technique was used to determine the tryptase genotype, and a standard fluoroenzyme immunoassay was used to measure total plasma tryptase levels in 106 healthy subjects. Mx modeling and the QTL association routine of Mendel 5.0 were used to analyze the data.
  
  
  RESULTS
  Tryptase haplotypes exhibit a 1 (betaalpha/betaalpha):2 (betabeta/betaalpha):1 (betabeta/betabeta) distribution, monomorphic for ss at 1 position and allelic for ss and alpha at the other position. The betaalpha haplotype has a frequency of 0.49. The betaalpha haplotype increases total tryptase levels by 0.5 ng/mL from the overall mean, whereas female sex increases the level by 0.2 ng/mL from the mean.
  
  
  CONCLUSIONS
  The tryptase haplotype and sex each have a statistically significant effect on the total plasma tryptase level of healthy subjects.
authors.affiliation: Department of Internal Medicine, Virginia Commonwealth University, Richmond, VA 23298, USA.
authors.forename: Hae-Ki
authors.initials: HK
authors.lastname: Min
authors.forename: George
authors.initials: G
authors.lastname: Moxley
authors.forename: Michael C
authors.initials: MC
authors.lastname: Neale
authors.forename: Lawrence B
authors.initials: LB
authors.lastname: Schwartz
mesh_terms: D000328:Adult; D005260:Female; D006239:Haplotypes / Q000235:genetics; D006801:Humans; D008297:Male; D008407:Mast Cells / Q000276:immunology* / Q000502:physiology; D016133:Polymerase Chain Reaction; D012016:Reference Values; D012697:Serine Endopeptidases / Q000097:blood* / Q000235:genetics*; D012737:Sex Factors; D053802:Tryptases
chemical_list: D012697:Serine Endopeptidases; D053802:Tryptases