Mondo Description Pterin-4 alpha-carbinolamine dehydratase 1 (PCBD1) deficiency is considered a transient and benign form of hyperphenylalaninemia due to tetrahydrobiopterin deficiency, characterized by muscular hypotonia, irritability (detected by EEG), slow acquisition of psychomotor skills, age-dependent movement disorders, including dystonia and an accompanying excretion of 7-substituted pterins. Neurological developement is normal with dietary control of blood phenyalanine. PCBD1 is inherited in an autosomal recessive manner.

Uniprot Description An autosomal recessive disease characterized by primapterinuria, a variant form of hyperphenylalaninemia defined by increased excretion of 7-substituted pterins in the urine. Patients with primapterinuria show an increased ratio of neopterin to biopterin in the urine, excretion of subnormal levels of biopterins, and normal levels of biogenic amines in cerebrospinal fluid. Neurologic signs are mild, present in the neonatal period only, and include hypotonia, delayed motor development and tremor.