Analysis of the CYP1A2 caffeine metabolism gene in the student population at Lake Superior State University

Abstract

85% of Americans drink caffeinated beverages on a daily basis. Each individual responds differently to caffeine depending on age, gender, diet, and ethnicity. Caffeinated beverages cause insomnia in some people, but not in others due to differences in the rate of caffeine metabolism. This study examines the variation in the caffeine metabolism of Lake Superior State University (LSSU) students. My hypothesis was that LSSU student allele frequencies would match those of the general population: 47.5% fast, 41.0% medium, and 11.5% slow caffeine metabolism. 200 LSSU students were sampled via buccal swabs. DNA was successfully isolated from 164 samples. Participants filled out a demographic questionnaire entailing caffeine intake, ethnicity, and sex. The CYP1A2 gene was amplified via standard PCR prior to genotyping by restriction digest and gel electrophoresis. The APAI restriction enzyme was used to determine the genotype of the rs762551 single nucleotide polymorphism (SNP), while the SACI enzyme was used as a positive digestion control. Overall, results showed a total of 42.7% fast, 44.5% medium, and 12.8% slow metabolizers. Of special note is that 24 of the 164 students sampled were of Native American heritage, an important yet underrepresented group in human genomics. This study provides the first reported look at the CYP1A2 variation within this North American subpopulation with metabolism rates being 50% fast, 33.3% medium, and 16.7% slow. The results confirm my initial hypothesis that the variation of caffeine metabolism gene frequencies for the LSSU student population would be representative of published allele frequencies for the general population.