SummaryConflicting results of an association between the human platelet antigen 1b (HPA-1b or PlA2) allele and the risk of myocardial infarction and coronary artery disease have been reported. To assess the reason for this discrepancy, we determined the HPA-1 genotype in 298 men who had undergone coronary angiography, including 124 individuals with myocardial infarction, 83 individuals with coronary artery disease but no history of myocardial infarction, and 91 control patients. Among patients with acute or recent onset myocardial infarction (<1 year), the prevalence of HPA-1b was higher than among patients with coronary artery disease but without myocardial infarction (33 percent vs. 14 percent, p = 0.016). In patients under 60 years of age this difference was even more pronounced (45 percent vs. 15 percent, p = 0.003). Unlike conventional risk factors HPA-1b does not represent a risk factor for coronary artery disease itself but appears to be associated with increased platelet thrombogenicity.

Genotyping of platelet alloantigens with the possibility of using any type of cellular material as a source of DNA has become a preferred procedure, particularly in thrombocytopenic patients when platelet counts are too low for phenotyping. Recently human platelet antigen 1 (HPA‐1) has been identified as an inherited risk factor for coronary thrombosis. The different detection methods currently used have disadvantages for large‐scale DNA diagnosis, including the need for electrophoresis (allele‐specific restriction enzyme analysis, amplification with sequence‐specific primers) or the potential risk of reduced specificity (allele‐specific oligonucleotide hybridization). In this report we describe the adaptation of an automated oligonucleotide ligation assay to genotype HPA‐1 in polymerase chain reaction (PCR)‐amplified DNA samples. HPA‐1a and HPA‐1b phenotypes corresponded to the results of the different genotyping assays. The genotypes determined with the ELISA‐based PCR‐oligonucleotide ligation assay were in 100% concordance with the results obtained by conventional allele‐specific restriction enzyme site analysis and PCR amplification with sequence‐specific primers. The automated oligonucleotide ligation assay provides a rapid, reliable, nonisotopic method to genotype human platelet antigens that can rapidly be applied to large population screening.

SummaryResistance of coagulation factor Va to inactivation by activated protein C (APCR) is associated with a point mutation in which adenine is substituted for guanine at nucleotide 1691 in the gene coding for factor V (FV Leiden). To date, this mutation of factor V is the most frequent genetic risk factor for venous thrombophilia. In this report, we describe the adaptation of an automatable oligonucleotide ligation assay (OLA) to detect the mutation in polymerase chain reaction-amplified DNA samples from 40 normal, 20 affected heterozygous, and 3 affected homozygous individuals. The genotypes determined by conventional allele-specific restriction enzyme site analysis were in complete concordance with the results obtained by ELISA-based oligonucleo-tide-ligation assay. The automated oligonucleotide ligation assay provides a rapid, reliable, nonisotopic method to detect the mutation responsible for APCR that can rapidly be applied to large population screening.

The results of our pilot study indicate that the GG genotype of the C1542G polymorphism of TAFI displays risk factors for the manifestation of thrombotic microangiopathies. Our observation provides a rationale to assess genotype-phenotype relations by determination of TAFI plasma levels in various stages of disease in patients suffering from these rare thrombotic disorders.