Background: The incidence of variant angina in oriental patients is higher than in patients from the Western world. Endothelin-1 (ET-1) seems to be associated with coronary vasospasm in variant angina, suggesting that ET-1 gene variants may be important in coronary vasospasm in variant angina. We wanted to assess potential association between Korean variant angina and three polymorphisms of the ET-1 gene, which include the +138delA polymorphism in exon 1, G8002A polymorphism in intron 4 and Lys198Asn polymorphism in exon 5.
Method: A total of 97 patients with variant angina and 111 healthy controls were studied. Analyses of the +138delA, G8002A and Lys198Asn polymorphisms were carried out by polymerase chain reaction-restriction fragment length polymorphism and haplotype techniques.
Results: The frequency of mutant 138delA allele was lower in the angina group than in controls [p=0.003, odds ratio (OR)=0.42] and the frequencies of A8002 or Asn198 were significantly higher in the variant angina group than in controls (p=0.005, OR=2.17 or p=0.009, OR=1.75, respectively). According to haplotype analysis, 4A/A8002/Asn198 haplotype was significantly associated with the disease (p=0.0162, OR=2.33) and 3A/G8002/Lys198 haplotype was protective against the disease (p=0.0043, OR=0.54).
Conclusions: The ET-1 gene polymorphisms, such as +138delA, G8002A and Lys198Asn polymorphisms, seem to be associated with variant angina in Korean patients.