Hyperphenylalaninemia due to DNAJC12 deficiency

A rare inborn error of metabolism characterized by increased serum phenylalanine, associated with variable neurological symptoms ranging from mild autistic features or hyperactivity to severe intellectual disability, dystonia, and parkinsonism. Laboratory analyses show normal tetrahydrobiopterin (BH4) metabolism and low levels of the CSF monoamine neurotransmitter metabolites homovanillic acid and 5-hydroxyindoleacetic acid.