Markers of cognitive function in patients with metabolic disease: Morquio Syndrome and Tyrosinemia Type III

Research output: Contribution to journalArticle


  • Anupam Chakrapani
  • Shauna Kearney
  • Suresh Vijay
  • Anita MacDonald
  • Paul Gissen
  • Chris Hendriksz

Colleges, School and Institutes

External organisations

  • Birmingham Children’s Hospital, Birmingham, UK
  • Great Ormond St Hosp Children
  • University of Pretoria
  • Birmingham Children's Hospital NHS Foundation Trust


We characterised cognitive function in two metabolic diseases. MPS-IVa (Morquio) and Tyrosinemia Type III individuals were assessed using tasks of attention, language and oculomotor function. MPS-IVa individuals were slower in visual search, but the display size effects were normal and slowing was not due to long reaction times (ruling out slow item processing or distraction). Maintaining gaze in an oculomotor task was difficult. Results implicated sustained attention and task initiation or response processing. Shifting attention, accumulating evidence and selecting targets were unaffected. Visual search was also slowed in Tyrosinemia Type III and patterns in visual search and fixation tasks pointed to sustained attention impairments, although there were differences from MPSIVa. Language was impaired in Tyrosinemia Type III but not MPS-IVa. Metabolic diseases produced selective cognitive effects. Our results, incorporating new methods for developmental data and model selection, illustrate how cognitive data can contribute to understanding function in biochemical brain systems.


Original languageEnglish
Pages (from-to)120-147
Number of pages28
JournalCognitive Neuropsychology
Issue number3-4
Early online date9 May 2018
Publication statusPublished - 2018


  • Morquio, MPS-IVa, Tyrosinemia, inherited metabolic disease, language, attention, developmental disorder