(dī-hī'drō-pī-rim'ĭ-dēn dē-hī'drō-jen-ās'), [MIM*274270] An enzyme in pyrimidine biosynthesis that reacts 5,6-dihydrouracil with NADP+ to form uracil and NADPH; it also acts on dihydrothymine; a deficiency of this enzyme can result in hyperuracil thyminuria. Synonym(s): dihydrouracil dehydrogenaseSeeDHP2SeeDPYD