The Relationship Between Polymorphisms on Chromosome 9p21 and Age of Onset of Coronary Heart Disease in Black and White Women

Abstract

Genome-wide association studies have identified variants on chromosome 9p21 that are associated with coronary heart disease (CHD). The relationship between these variants and the age of onset of CHD is less clear. The aim of this study was to examine the allelic frequencies and haplotype structure of eight single-nucleotide polymorphisms (SNPs) on chromosome 9p21 in ethnically diverse women. We also explored the relationship between 9p21 SNPs and the age of CHD onset. There was considerable interethnic allelic and haplotype diversity across the 9p21 locus with only two SNPs (rs10757274 and rs4977574) in perfect linkage disequilibrium in both races, and only a small proportion of the haplotypes shared between the racial groups. With the exception of rs1333040, whites with at least one copy of the 9p21 SNP risk alleles were found to have CHD from 1.45 (rs10116277) to 4.77 (rs2383206) years earlier than those with the wild-type alleles. Blacks carrying at least one copy of the risk allele (92%) for rs1333040 had a CHD age of onset that was 6.5 years earlier than those with the wild-type alleles. Different variants on chromosome 9p21 may influence CHD age of onset in whites and blacks.