Genomic analysis of patients with DPD deficiency has identified over 128 mutations and polymorphisms in the DPYD gene, but only four high-risk variants (DPYD*2A, DPYD*13, DPYD*9B, and HapB3) have been consistently associated with DPD deficiency and FrAEs. The gene discussed is DPYD; the disease is dihydropyrimidine dehydrogenase deficiency.