Sepiapterin reductase deficiency

Sepiapterin reductase deficiency is a very rare autosomal recessive disease resulting in monoamine neurotransmitter depletion. Patients exhibit progressive psychomotor retardation, dystonia, dopamine and serotonin deficiencies. Mutations in the SPR gene have been reported. Sepiapterin reductase catalyzes the final step in the de novo synthesis of tetrahydrobiopterin, essential cofactor for phenylalanine, tyrosine, and tryptophan hydroxylases.