title: Coronary artery disease and polymorphisms in a receptor mediating shear stress-dependent platelet activation.
abstract: BACKGROUND
  Platelets play pivotal roles in coronary thrombosis, and antiplatelet therapies are widely used for coronary artery disease (CAD). However, the effects of genetic variation in platelets on CAD are poorly understood. We have assessed the association between CAD and polymorphisms in a platelet receptor for von Willebrand factor, the glycoprotein (GP) Ib/IX complex, which mediates shear stress-dependent platelet activation.
  
  
  RESULTS
  Genotypes of the alpha-chain of the receptor (GP Ib alpha, 145Thr/Met) were determined in 91 patients with myocardial infarction (MI) or angina pectoris whose lesions were confirmed by coronary angiography as well as in 105 individuals from the general population with no history of angina or other heart diseases and normal resting ECGs. There was no homozygote for Met/Met in either the control or patient groups. The prevalence of the Thr/Met genotype (T/M) in all patients was not significantly different from that in the control group. However, the frequency of T/M was significantly higher in patients aged < or = 60 years (31.8%) than in control subjects aged < or = 60 years (16.0%; P<.05, odds ratio=2.5). An association was also demonstrated between CAD and the other polymorphism of GP Ib alpha, a variable number of tandem repeats of a 13-amino acid sequence, which is known to be linked to the 145Thr/Met polymorphism. There was an association between the frequency of the T/M genotype and the angiographic severity of CAD: 11.1% for Gensini score < 40 versus 50.0% for Gensini score > or = 40 (P=.0015). There was no difference in the distribution of GP Ib alpha genotypes between patients with MI and those with angina pectoris.
  
  
  CONCLUSIONS
  This study suggests that the presence of the Met allele in GP Ib alpha is a risk factor for the prevalence and severity of CAD in individuals aged < or = 60 years. The results need to be confirmed in a large-scale study of incident case subjects and matching control subjects.
authors.affiliation: Department of Medicine, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Murata
authors.forename: Y
authors.initials: Y
authors.lastname: Matsubara
authors.forename: K
authors.initials: K
authors.lastname: Kawano
authors.forename: T
authors.initials: T
authors.lastname: Zama
authors.forename: N
authors.initials: N
authors.lastname: Aoki
authors.forename: H
authors.initials: H
authors.lastname: Yoshino
authors.forename: G
authors.initials: G
authors.lastname: Watanabe
authors.forename: K
authors.initials: K
authors.lastname: Ishikawa
authors.forename: Y
authors.initials: Y
authors.lastname: Ikeda
mesh_terms: D000328:Adult; D000483:Alleles; D000787:Angina Pectoris / Q000235:genetics / Q000503:physiopathology; D001792:Blood Platelets / Q000378:metabolism*; D003327:Coronary Disease / Q000235:genetics* / Q000503:physiopathology; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000235:genetics / Q000503:physiopathology; D015539:Platelet Activation / Q000502:physiology*; D019038:Platelet Glycoprotein GPIb-IX Complex / Q000502:physiology*; D011110:Polymorphism, Genetic / Q000235:genetics*; D012016:Reference Values; D012307:Risk Factors; D013314:Stress, Mechanical
chemical_list: D019038:Platelet Glycoprotein GPIb-IX Complex