Article

Dihydropyrimidine dehydrogenase deficiency in an Indian population.

Yale University School of Medicine, New Haven, CT 06520, USA.
Cancer Chemotherapy and Pharmacology (Impact Factor: 2.57). 10/2006; 58(3):396-401. DOI: 10.1007/s00280-005-0174-5
Source: PubMed

ABSTRACT Dihydropyrimidine dehydrogenase (DPD) deficiency is prevalent in 3-5% of the Caucasian population; however, the frequency of this pharmacogenetic syndrome in the Indian population and other racial and ethnic groups remains to be elucidated.
We describe an Indian patient who presented to clinic for the treatment of gastric adenocarcinoma with 5-flurouracil (5-FU) therapy who subsequently was diagnosed with DPD deficiency by using the peripheral blood mononuclear cell (PBMC) DPD radioassay. This observation prompted us to examine the data generated from healthy (cancer-free) Indian subjects who were enrolled in a large population study to determine the sensitivity and specificity of the uracil breath test (UraBT) in the detection of DPD deficiency. Thirteen Indian subjects performed the UraBT. UraBT results were confirmed by PBMC DPD radioassay.
The Indian cancer patient demonstrated reduced DPD activity (0.11 nmol/min/mg protein) and severe 5-FU toxicities commonly associated with DPD deficiency. Of the 13 Indian subjects [ten men and three women; mean age, 26 years (range: 21-31 years)] enrolled in the UraBT, 12 Indian subjects demonstrated UraBT breath profiles and PBMC DPD activity within the normal range; one Indian subject demonstrated a reduced breath profile and partial DPD deficiency.
DPD deficiency is a pharmacogenetic syndrome which is also present in the Indian population. If undiagnosed, the DPD deficiency can lead to death. Future epidemiological studies would be helpful to determine the prevalence of DPD deficiency among racial and ethnic groups, allowing for the optimization of 5-FU chemotherapy.

Download full-text

Full-text

Available from: Robert B Diasio, Jul 04, 2015
0 Followers
 · 
107 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In the field of pharmacogenetics, we currently have a few markers to guide physicians as to the best course of therapy for patients. For the most part, these genetic variants are within a drug metabolizing enzyme that has a large effect on the degree or rate at which a drug is converted to its metabolites. For many drugs, response and toxicity are multi-genic traits and understanding relationships between a patient's genetic variation in drug metabolizing enzymes and the efficacy and/or toxicity of a medication offers the potential to optimize therapies. This review will focus on variants in drug metabolizing enzymes with predictable and relatively large impacts on drug efficacy and/or toxicity; some of these drug/gene variant pairs have impacted drug labels by the United States Food and Drug Administration. The challenges in identifying genetic markers and implementing clinical changes based on known markers will be discussed. In addition, the impact of next generation sequencing in identifying rare variants will be addressed.
    Current Drug Metabolism 04/2011; 12(5):487-97. DOI:10.2174/138920011795495321 · 3.49 Impact Factor
  • Source
    Clinical Cancer Research 08/2006; 12(14 Pt 1):4137-41. DOI:10.1158/1078-0432.CCR-06-0707 · 8.19 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: African-American patients with colorectal cancer were observed to have increased 5-fluorouracil (5-FU)-associated toxicity (leukopenia and anemia) and decreased overall survival compared with Caucasian patients. One potential source for this disparity may be differences in 5-FU metabolism. Dihydropyrimidine dehydrogenase (DPD), the initial and rate-limiting enzyme of 5-FU catabolism, has previously been shown to have significant interpatient variability in activity. Several studies have linked reduced DPD activity to the development of 5-FU toxicity. Although the distribution of DPD enzyme activity and the frequency of DPD deficiency have been well characterized in the Caucasian population, the distribution of DPD enzyme activity and the frequency of DPD deficiency in the African-American population are unknown. Healthy African-American (n=149) and Caucasian (n=109) volunteers were evaluated for DPD deficiency using both the [2-(13)C]uracil breath test and peripheral blood mononuclear cell DPD radioassay. African-Americans showed significantly reduced peripheral blood mononuclear cell DPD enzyme activity compared with Caucasians (0.26+/-0.07 and 0.29+/-0.07 nmol/min/mg, respectively; P=0.002). The prevalence of DPD deficiency was 3-fold higher in African-Americans compared with Caucasians (8.0% and 2.8%, respectively; P=0.07). African-American women showed the highest prevalence of DPD deficiency compared with African-American men, Caucasian women, and Caucasian men (12.3%, 4.0%, 3.5%, and 1.9%, respectively). These results indicate that African-Americans, particularly African-American women, have significantly reduced DPD enzyme activity compared with Caucasians, which may predispose this population to more 5-FU toxicity.
    Clinical Cancer Research 10/2006; 12(18):5491-5. DOI:10.1158/1078-0432.CCR-06-0747 · 8.19 Impact Factor