Affiliations: Department of Pharmacology, University of Zaragoza,
Zaragoza, Spain | Laboratory of Molecular Genetics, Hospital
Metropolitano, Quito, Ecuador | Department of Legal Medicine. University of Zaragoza,
Zaragoza, Spain
Abstract: Polymorphisms in CYP3A genes, such as CYP3A5} and
CYP3A4, as well as in the MDR1 gene, which encodes for P-glycoprotein,
have been implicated as genetic markers in several disorders. Differences in
the frequency distribution of the allelic variants CYP3A5*3,
CYP3A4*1B, and MDR1 3435T have been demonstrated between distinct ethnic
groups. In this study we examined the frequency of these allelic variants in
317 healthy Mestizo individuals from Ecuador and made comparisons with results
reported in the literature. The genotypes were determined by PCR-RFLP. Allele
and genotype differences were studied by chi-square test. The MDR1 T
allele frequency was similar to that of Spaniard or Asian populations, which is
consistent with the ethnic origin of Ecuadorian Mestizo individuals (Amerindian
and Spaniard Caucasians). By contrast, the CYP3A5*3 allele frequency was
significantly lower in Ecuadorians than in Spaniards and other white
populations and higher than in Central Americans, Asians and blacks.
CYP3A4*1B was more common in Ecuadorians than in Caucasian or Asian
populations but less present than in blacks. The differences in the
polymorphism found in this work should be considered in allele-disease
association studies.
