Research has shown that DPYD-guided dose-individualization based on 4 DPYD variants (DPYD*2A, c.1236G>A, c.2846A>T and c.1679T>G) can significantly reduce severe fluoropyrimidine-related toxicity. However, these 4 variants are most likely not predictive for toxicity in patients of non-Western descent. In this study the DPYD gene of patients of non-Western descent will be sequenced to identify novel variants that could be associated with a reduced DPD enzyme activity and an increased risk of developing severe fluoropyrimdine-related toxicity. Additionally, the ability to predict if a DPYD variant is possibly deleterious by a recombinant model systen (DPYD-varifier) will be studied.
This is a observational, multicenter study to identify novel variants of the DPYD gene which are possible deleterious in patients of non-Western descent.