The Frequency of CYP3A5 Expression in a Mexican Population Compared to a Caucasian Population

Aims: To determine the frequencies of the six most common CYP3A5 alleles and genotypes in a Mexican-American population compared to a non-Hispanic Caucasian population.

Study Design: This cross-sectional study compared the frequency of CYP3A5 genetic variations in a Mexican-American population compared to a non-Hispanic Caucasian population.

Duration of Study: The study was conducted from September 2014 to April 2015.

Methodology: There were 236 Mexican-American and 237 non-Hispanic Caucasian samples that were analyzed. The two groups of subjects’ gDNA were analyzed for CYP3A5 rs776746 (*3), rs56411402 (*4), rs10264272 (*6), rs41303343 (*7), rs55817950 (*8), and rs28383479 (*9).

Results: There was a significant difference in the CYP3A5*3 containing diplotypes, but no other diplotypes were significantly different. The frequency of the CYP3A5*3 allele in the Mexican population was 0.782, which was significantly lower than the frequency of the CYP3A5*3 allele in the non-Hispanic Caucasian population of 0.932 (P <0.001). The CYP3A5*7 frequency was very low in the Mexican-American group at 0.85% and was absent in the Caucasian group (P = 0.045). Mexican-Americans were three times more likely to be CYP3A5 expressers compared to non-Hispanic Caucasians (P <0.001).

Conclusion: CYP3A5*3 and *7 allele frequencies vary significantly between Mexicans and non-Hispanic Caucasians, while other allele frequencies for CYP3A5*4, *6, *8 and *9 do not vary significantly between Mexicans and non-Hispanic Caucasians. Mexican-Americans were shown to have a three-fold higher frequency of CYP3A5 expression compared to non-Hispanic Caucasians.