Association of 5′ upstream promoter region of prostacyclin synthase gene variant with cerebral infarction

The aim of this study was to investigate whether there is an association between the promoter region of the prostacyclin synthase gene and cerebral infarction (CI). Using the polymerase chain reaction–single strand conformation polymorphism (PCR-SSCP) method, we found a variable-number tandem repeat polymorphism in the 5′-upstream promoter region of the prostacyclin synthase gene. This region contains transcriptional factors–binding sites of Sp1 (CCCGCC) and AP-2 (CCGCCAGCCCC). The alleles varied in size from three to seven repeats of nine base pairs (bp). We performed an association study using the polymorphism in 111 patients and 152 control subjects. The transcriptional activity of the abnormal promoter region allele was determined by luciferase assay. The overall distribution of alleles differed significantly between both groups. Logistic linear regression analysis revealed the small number repeat allele to be found more frequently with CI. Transcriptional activity increased with increasing numbers of repeats. This study provides consistent support for the association between CI and the PGIS gene.