DPD deficiency

DPD deficiency is an autosomal recessive metabolic disorder due to a decreased activity of the enzyme dihydropyrimidine dehydrogenase (DPD), an enzyme that catalyses the rate-limiting step in 5-FU metabolism, encoded by the DPYD gene. Individuals who carry at least one copy of no-function DPYD variants, may not be able to metabolize those drugs at normal rates, and are at risk of potentially life-threatening toxicity. The stratification of patients based on the DPYD genotype may help to prevent such adverse events. The prevalence of DPD deficiency in Caucasians is approximately 3%-5%. Symptomatic DPD deficiency is typically caused by homozygous inactivation of DPYD; whereas individuals who are heterozygotes tend to be asymptomatic. Signs of fluoropyrimidine toxicity include severe diarrhea, severe mucositis, neutropenia, neurotoxicity, and handfoot syndrome (redness, swelling, and blisters on the palms of the hands and soles of the feet).

DPYD*2A

Also referred to as rs3918290 or c.1905+1 G>A. The A allele of rs3918290 is associated with toxicity.

DPYD*13

Also referred to as c.1679 T>G, I560S or rs55886062

DPYD rs67376798

Also referred to as D949V or c.2846A>T

DPYD rs56038477

Also referred to as c.1236G>A or E412E; rs56038477