title: Letter: Biopterin derivatives in atypical phenylketonuria.
mesh_terms: D001708:Biopterins / Q000097:blood / Q000378:metabolism* / Q000652:urine; D002675:Child, Preschool; D005260:Female; D006801:Humans; D010661:Phenylketonurias / Q000097:blood / Q000378:metabolism* / Q000652:urine; D011621:Pteridines / Q000378:metabolism*
chemical_list: D011621:Pteridines; D001708:Biopterins