The principal outcomes gained from our study were: (I) Heterozygous, homozygous mutant genotypes and mutant C allele of rs4646903 polymorphism elevated CAD risk (II) The CYP1A1 rs4646903 polymorphism acts as a significant risk factor for development of early onset but not late onset CAD (III) Rs4646903 polymorphism didn’t influence stenosis severity. The gene discussed is CYP1A1; the disease is coronary artery disorder.