A case in point is the rare but
severe psychomotor disease Allan - Herndon - Dudley syndrome (AHDS), a congenital condition that affects only males and starves the
developing brain of thyroid hormone, resulting in
cognitive impairment and atrophied muscles and motor skills.
Intellectual disability (ID) affects 143/10 000 children1 and is associated with a range of comorbid health conditions.2 — 4 It is heterogeneous, 5 and clustering of some medical conditions may be associated with particular disorders such as Down syndrome6 or Prader - Willi syndrome.7 While epilepsy and sensory
impairments often occur in association with specific syndromes or more
severe cognitive impairment, conditions such as fractures or obesity may
develop as secondary to medication use, nutritional deficiency or lack of mobility.2 Consequently, children with ID may face greater health challenges than typically
developing children and use healthcare systems more frequently.8, 9 Mental health problems are also common in people with ID.10 For instance, in a Canadian adolescent and adult population with ID, a high proportion of hospitalisations was attributed to the presence of psychiatric conditions.11