Analysis index

2 ml EDTA-blood and consent declaration

Demonstration of a defect in Dihydropyrimidine dehydrogenase (DPD) (Exon-14-skipping-mutation) prior to therapy with fluoropyrimidines such as capecitabine (Xeloda®) or 5-fluorouracil especially in case of signs of an intoxication (neutropenia)

The enzyme DPD usually degrades 80 % of 5-fluorouracil within a very short time. In 1 – 3 % of patients who are treated with 5-fluorouracil as a result of a mamma carcinoma or a gastrointestinal tumor, severe and even deadly side effects occur, which are attributed to a decrease in Dihydropyrimidine dehydrogenase-activity and therefore very high 5-fluorouracil levels. More than half of the cases of decreased DPD-activity are caused by a mutation in the DPD-gene (Exon-14-skipping-mutation). Incidence of heterozygous mutation is at 1 – 1,8 % in the total population, incidence of homozygous mutation at 1:42.000.