Genetic variants of the drug-metabolizing enzyme CYP2D6 in Puerto Rican psychiatry patients: a preliminary report and potential implications for breast cancer patients.
BACKGROUND
The CYP2D6 liver enzyme, which metabolizes 25-30% of common medications, is highly polymorphic. Existing studies of Hispanics have focused on Mexicans and Mexican-Americans. The goal of the study was to identify the CYP2D6 alleles associated with reduced or negligible activities present in the Puerto Rican population.


METHODS
The study cohort comprised 40 Puerto Rican psychiatric patients referred because of suspected intolerance of drugs metabolized by CYP2D6, and five subjects without suspected adverse responses to these drugs. All subjects had both parents and all grandparents born in Puerto Rico. Genomic DNA was queried for 27 CYP2D6 alleles using the Roche AmpliChip P450 test.


RESULTS
A total of 12 alleles were identified. The most common alleles were CYP2D6*1 > *2 > *4 > *41. The inactive alleles were *4 > * 5 > * 31 >*40; reduced activity alleles were *10 >* 17 > *9* = *29; active alleles were *1 > *2 > *35. Two subjects carried the rare *31 allele. Only one subject carried two non-functional alleles (CYP2D6*5/*40), and was predicted to be a poor metabolizer.


CONCLUSIONS
Any conclusions should be interpreted with caution given the small population sample investigated. Nonetheless, our findings strongly suggest that Puerto Ricans exhibit distinct CYP2D6 allele frequencies and harbor a non-functional allele that is rare or absent in other populations and are highly valuable for the emerging practice of Personalized Medicine in admixed populations like Puerto Ricans.
González-Tejera
Gloria
G
Department of Psychiatry, University of Puerto Rico School of Medicine, San Juan, Puerto Rico 00936.
Gaedigk
Andrea
A
Corey
Susan
S
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D001943:Breast Neoplasms / Q000201:enzymology / Q000235:genetics; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D019389:Cytochrome P-450 CYP2D6 / Q000235:genetics*; D005260:Female; D014644:Genetic Variation; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000188:drug therapy / Q000201:enzymology* / Q000235:genetics*; D008875:Middle Aged; D010865:Pilot Projects; D011647:Puerto Rico; D055815:Young Adult
D019389:Cytochrome P-450 CYP2D6