Neuropsychiatric Manifestations in Late-Onset Urea Cycle Disorder Patients
- Serrano, Mercedes MD, PhD
- Martins, Cecilia MD
- Pérez-Dueñas, Belén MD, PhD
- Gómez-López, Lilian MD
- Murgui, Empar MD
- Fons, Carmen MD
- García-Cazorla, Angels MD, PhD
- Artuch, Rafael MD, PhD
- Jara, Fernando MD
- Arranz, José A. MSc
- Häberle, Johannes PhD
- Briones, Paz PhD
- Campistol, Jaume MD, PhD
- Pineda, Mercedes MD, PhD
- Vilaseca, Maria A. PhD
Inherited urea cycle disorders represent one of the most common groups of inborn errors of metabolism. Late-onset urea cycle disorders caused by partial enzyme deficiencies may present with unexpected clinical phenotypes. We report 9 patients followed up in our hospital presenting late-onset urea cycle disorders who initially manifested neuropsychiatric/neurodevelopmental symptoms (the most prevalent neuropsychiatric/neurodevelopmental diagnoses were mental retardation, attention-deficit hyperactivity disorder [ADHD], language disorder, and delirium). Generally, these clinical pictures did not benefit from pharmacological treatment. Conversely, dietary treatment improved the symptoms. Regarding biochemical data, 2 patients showed normal ammonium but high glutamine levels. This study highlights the fact that neuropsychiatric/neurodevelopmental findings are common among the initial symptomatology of late-onset urea cycle disorders. The authors recommend that unexplained or nonresponsive neuropsychiatric/neurodevelopmental symptoms appearing during childhood or adolescence be followed by a study of ammonia and amino acid plasmatic levels to rule out a urea cycle disorder.