The variable number of tandem repeat polymorphism in the P-selectin glycoprotein ligand-1 gene is not associated with coronary heart disease.

Abstract

Genes involved in inflammatory processes are candidates for predisposition to prothrombotic syndromes. The variable number of tandem repeat (VNTR) polymorphism in the P-selectin glycoprotein ligand (PSGL)-1 gene has been associated with ischemic cerebrovascular disease but not with coronary heart disease (CHD). We assessed the effect of the VNTR polymorphism on CHD in two independent case/control studies. In the first study 281 CHD patients and 397 healthy blood donors were genotyped for the VNTR alleles in PSGL-1. The prevalence of homozygous carriers of the PSGL-1 VNTR allele with 15 repeat units was significantly higher in the CHD patients (5.3% vs. 1.5%) than in controls, suggesting an effect of this marker in CHD. To validate the findings genotyping was performed in a second study including 2,578 CHD patients, 731 patients without CHD, and 1084 healthy blood donors. The larger case control study had a power of 99.9% to detect the initially observed difference but failed to confirm the putative role of PSGL-1 VNTR polymorphism in CHD. Frequencies of the PSGL-1 VNTR 15 repeats for homozygous carriers were 2.2% in healthy blood donors, 2.3% in patients without CHD and 2.7%, in CHD cases, respectively. These results demonstrate that the PSGL-1 VNTR polymorphism is not a genetic risk factor for CHD. Adequately powered studies are prerequisites to obtain reliable results about genotype-phenotype relationships of new candidate genes in complex diseases.