title: Treatable neurotransmitter deficiency in mild phenylketonuria.
abstract: The authors describe a case of neurologic involvement in mild hyperphenylalaninemia (HPA), not due to tetrahydrobiopterin (BH(4)) deficiency, with low levels of monoamine neurotransmitter metabolites in CSF. The combined BH(4)-Phe loading test suggested a BH(4) response, confirmed by clinical improvement after BH(4) therapy. Molecular study revealed a compound heterozygosity of the phenylalanine hydroxylase alleles: a mild HPA-associated mutation (T380M) and the new mutation D151E. This case demonstrates that even mild HPA, generally considered a benign disorder, may present neurologic impairment.
authors.affiliation: Division of Clinical Chemistry, Department of Pediatrics, University Children's Hospital, Zürich, Switzerland.
authors.forename: L
authors.initials: L
authors.lastname: Bonafé
authors.forename: N
authors.initials: N
authors.lastname: Blau
authors.forename: A P
authors.initials: AP
authors.lastname: Burlina
authors.forename: A
authors.initials: A
authors.lastname: Romstad
authors.forename: F
authors.initials: F
authors.lastname: Güttler
authors.forename: A B
authors.initials: AB
authors.lastname: Burlina
mesh_terms: D000293:Adolescent; D000975:Antioxidants / Q000627:therapeutic use*; D015306:Biogenic Monoamines / Q000097:blood / Q000172:deficiency*; D001708:Biopterins / Q000031:analogs & derivatives* / Q000097:blood / Q000172:deficiency* / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D010649:Phenylalanine / Q000097:blood / Q000627:therapeutic use; D010661:Phenylketonurias / Q000097:blood / Q000188:drug therapy*; D014443:Tyrosine / Q000097:blood
chemical_list: D000975:Antioxidants; D015306:Biogenic Monoamines; D001708:Biopterins; D014443:Tyrosine; D010649:Phenylalanine; C003402:sapropterin