Genetic Variation at a Metallothionein 2A Promoter Single-Nucleotide Polymorphism in White and Black Females in Midwestern United States

Genetic variation leading to differences in expression and regulation of metallothionein proteins may contribute to observed differences among individuals in terms of cadmium (Cd) uptake and metabolism. The aim of this study was to determine the frequency of the A and G alleles at rs28366003, which lies in the 5' promoter region of MT2A, in White and Black females in the Midwestern United States. One-milliliter saliva samples were collected from 298 White or Black adult female volunteers, and DNA was isolated from each sample using Oragene*DNA kits. Allele-specific PCR with gel visualization of amplification products was used to genotype SNP rs28366003. Of the 291 participants (Black = 142; White = 149), the average yield of DNA extracted from the saliva samples was 23.4 g. The samples, quantitated on a spectrophotometer, achieved an average 260/280 optical density reading of 1.61. The frequency of the G allele was 1.1% for Blacks and 6.4% for Whites. Data demonstrated that the G allele is not common in both the Midwestern U.S. Black and White female population and is less frequent than that reported for an Asian population.