title: A DPYD variant (Y186C) in individuals of african ancestry is associated with reduced DPD enzyme activity.
abstract: 5-Fluorouracil (5-FU) is used to treat many aggressive cancers, such as those of the colon, breast, and head and neck. The responses to 5-FU, with respect to both toxicity and efficacy, vary among racial groups, potentially because of variability in the activity levels of the enzyme dihydropyrimidine dehydrogenase (DPD, encoded by the DPYD gene). In this study, the genetic associations between DPYD variations and circulating mononuclear-cell DPD enzyme activity were evaluated in 94 African-American and 81 European-American volunteers. The DPYD-Y186C variant was unique to individuals of African ancestry, and DPD activity was 46% lower in carriers as compared with noncarriers (279 ± 35 vs. 514 ± 168 pmol 5-FU min(-1) mg(-1); P = 0.00029). In this study, 26% of the African Americans with reduced DPD activity were carriers of Y186C. In the African-American cohort, after excluding Y186C carriers, homozygous carriers of C29R showed 27% higher DPD activity as compared with noncarriers (609 ± 152 and 480 ± 152 pmol 5-FU min(-1) mg(-1), respectively; P = 0.013).
authors.affiliation: Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic Cancer Center, Rochester, Minnesota, USA.
authors.forename: S M
authors.initials: SM
authors.lastname: Offer
authors.forename: A M
authors.initials: AM
authors.lastname: Lee
authors.forename: L K
authors.initials: LK
authors.lastname: Mattison
authors.forename: C
authors.initials: C
authors.lastname: Fossum
authors.forename: N J
authors.initials: NJ
authors.lastname: Wegner
authors.forename: R B
authors.initials: RB
authors.lastname: Diasio
mesh_terms: D000328:Adult; D001741:Black or African American / Q000235:genetics*; D000964:Antimetabolites, Antineoplastic / Q000627:therapeutic use*; D015331:Cohort Studies; D042943:Dihydrouracil Dehydrogenase (NADP) / Q000235:genetics* / Q000378:metabolism; D005260:Female; D005472:Fluorouracil / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D009369:Neoplasms / Q000188:drug therapy* / Q000201:enzymology; D044465:White People / Q000235:genetics; D055815:Young Adult
chemical_list: D000964:Antimetabolites, Antineoplastic; D042943:Dihydrouracil Dehydrogenase (NADP); D005472:Fluorouracil