Educational objective: Tetrahydrobiopterin (BH.) is a cofactor | Uworld | Step 1

Educational objective: Tetrahydrobiopterin (BH.) is a cofactor used by hydroxylase enzymes in the synthesis of tyrosine, dopamine, and serotonin. Phenylketonuria can result from BH. deficiency due to dihydropteridine reductase deficiency.
Intellectual disability is the hallmark of this condition and results in neurotransmitter
(eg, serotonin) deficiency and hyperphenylalanemia. Treatment involves a low phenylalanine diet and BH. supplementation.