Sepiapterin reductase deficiency is a genetic disorder that is characterized by abnormal levels of neurotransmitters and pterins. It is caused an autosomal recessive genetic mutation in the SPR gene which leads to the underproduction of the enzyme sepiapterin reductase. Sepiapterin reductase is an enzyme required in multiple steps of the synthesis of tetrahydrobiopterin which is needed in the synthesis of the neurotransmitters dopamine and serotonin. The deficiency of sepiapterin reductase also causes an accumulation of sepiapterin. Symptoms of sepiapterin reductase deficiency include Motor and speech delay, axial hypotonia, dystonia, weakenss microcephaly, dysarthria, autonomic dysfunction, oculogyric crises, and drowsiness. Parkinsonian signs (tremor, bradykinesia, masked facies, rigidity), limb hypertonia, hyperreflexia, intellectual disability, psychiatric and/or behavioral abnormalities, autonomic dysfunction, and sleep disturbances are also common features of Sepiapterin reductase deficiency.

Sepiapterin Reductase Deficiency References