INTRODUCTION: We examined previously the genomic structure of the humannatriuretic peptide receptor type B (hNPRB) gene and reported a C2077T polymorphism located in exon 11of the gene. We now have studied the C2077T polymorphism in myocardial infarction [MI] patients and non-MI[control] subjects to evaluate the value of this polymorphism as a marker for MI. MATERIAL AND METHODS:302 subjects (163 MI patients and 139 non-MI age-matched control subjects) were studied. PCR-restrictionfragment length polymorphism analysis (PCR-RFLP) was developed to detect the C2077T transition. RESULTS:The distribution of C2077T polymorphism genotypes in the MI patients (CC:CT:TT, 47.2%:41.1%:11.7%) wasnot significantly different from that in the control patients (CC:CT:TT, 53.2%:40.3%:6.5%) (chi 2 = 2.73,p = NS). Allele frequencies of the C2077T polymorphism were f(C/T) 68.2%/31.8% in the MI group and 73.4%/26.6%in the control group. However, no association was found between this polymorphism and clinical diagnosisof MI. CONCLUSION: Our data indicate that the C2077T polymorphism is not a useful marker of the relationbetween the hNPRB gene and MI in the Japanese and variations of the hNPRB gene that may be in linkagedisequilibrium with this polymorphism do not play a causative role in MI.

Keywords: Receptors, Atrial Natriuretic Factor