title: Late-diagnosed phenylketonuria in an eight-year-old boy with dyslexia and attention-deficit hyperactivity disorder.
abstract: Phenylketonuria, previously a common cause of severe intellectual disability, is a metabolic disorder now promptly diagnosed and effectively treated thanks to newborn screening programs. Here, we report a male patient presenting with dyslexia and attention-deficit hyperactivity disorder, who was diagnosed with mild phenylketonuria at eight years of age. Earlier recognition and treatment before the establishment of irreversible brain damage would have resulted in better neurobehavioural outcomes. Classical phenylketonuria and milder phenotypes of phenylalanine hydroxylase deficiency need to be considered in the differential diagnosis of all cognitive and behavioural problems of unknown cause.
authors.affiliation: Pediatric Metabolic Diseases Unit, Department of Pediatrics, Hacettepe University Faculy of Medicine, Ankara, Turkey.
authors.forename: Yılmaz
authors.initials: Y
authors.lastname: Yıldız
authors.affiliation: Pediatric Metabolic Diseases Unit, Department of Pediatrics, Hacettepe University Faculy of Medicine, Ankara, Turkey.
authors.forename: Ali
authors.initials: A
authors.lastname: Dursun
authors.affiliation: Pediatric Metabolic Diseases Unit, Department of Pediatrics, Hacettepe University Faculy of Medicine, Ankara, Turkey.
authors.forename: Ayşegül
authors.initials: A
authors.lastname: Tokatlı
authors.affiliation: Pediatric Metabolic Diseases Unit, Department of Pediatrics, Hacettepe University Faculy of Medicine, Ankara, Turkey.
authors.forename: Turgay
authors.initials: T
authors.lastname: Coşkun
authors.affiliation: Pediatric Metabolic Diseases Unit, Department of Pediatrics, Hacettepe University Faculy of Medicine, Ankara, Turkey.
authors.forename: Hatice Serap
authors.initials: HS
authors.lastname: Sivri
mesh_terms: D001289:Attention Deficit Disorder with Hyperactivity / Q000150:complications*; D002648:Child; D057210:Delayed Diagnosis; D003937:Diagnosis, Differential; D004410:Dyslexia / Q000150:complications*; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D015997:Neonatal Screening; D010649:Phenylalanine / Q000097:blood*; D010661:Phenylketonurias / Q000150:complications / Q000175:diagnosis*
chemical_list: D010649:Phenylalanine
keywords: attention-deficit hyperactivity disorder; dyslexia; intellectual disability; phenylalanine hydroxylase deficiency; phenylketonuria