Dihydropteridine reductase deficiency (DHPRD) is a rare genetic disorder caused by a deficiency of the enzyme dihydropteridine reductase (DHPR). This enzyme is responsible for the conversion of the essential vitamin folate into its active form, tetrahydrofolate. Without this enzyme, folate cannot be used by the body, leading to a deficiency of folate and other essential vitamins and minerals. Symptoms of DHPRD include developmental delays, seizures, vision and hearing loss, and intellectual disability. Treatment typically involves supplementation with folate and other vitamins and minerals.