P678: Role of de novo variants in genetic disorders with new insights and clinical implications

95% of DPD deficiencies within the population.In addition, validation of an in-house DPYD full gene sequencing is in progress to detect rare variants other than the most common ones.Results: So far, 202 cancer patients have been subjected to DPYD genotyping prior to chemotherapy.Thirteen of them were detected to have a reduced function or non-function allele, which accounts for ~6.5% in patient population.Their doses of 5-FU/capecitabine were adjusted accordingly to prevent the risk of severe side effects.Conclusion: DPYD testing allows for the early detection of DPD deficiencies, which improves patient outcomes by adjusting the dosage of fluoropyrimidine drugs used in chemotherapy treatment, overall reducing the risk of severe side effects.Local availability of these tests allows cancer patients to access safe, effective treatment much faster.