Core neuropsychological characteristics of children and adolescents with 22q11.2 deletion

J Intellect Disabil Res. 2010 Aug;54(8):701-13. doi: 10.1111/j.1365-2788.2010.01298.x. Epub 2010 Jun 17.

Abstract

Background: The 22q11.2 deletion syndrome (22qDS) confers high risk for intellectual disability and neuropsychological/academic impairment, although a minority of patients show average intelligence. Intellectual heterogeneity and the high prevalence of psychiatric diagnoses in earlier studies may have obscured the prototypical neuropsychological profile in 22qDS.

Methods: We examined intelligence, memory, reading and mathematical processes in 31 children/adolescents with 22qDS, selected for educational underachievement and an absence of psychiatric diagnoses, using standardised, psychometrically matched instruments that specify how typical a score is for a given intelligence quotient (IQ).

Results: Corroborating earlier findings, verbal IQ was significantly superior to performance IQ; verbal memory and basic reading were relative strengths; and visual/spatial memory was a relative weakness. All four findings transcended performance characteristics that are typical of low-IQ individuals. Rote learning yielded the highest score; reading comprehension, numerical operations and mathematical reasoning were among the lowest-performed academic domains. Albeit in the expected direction, performance in the respective components could not be clearly differentiated from what is IQ-appropriate.

Conclusions: A superiority of verbal intelligence over non-verbal intelligence, relative strengths in verbal memory and basic reading, and a relative weakness in visual/spatial memory are likely to be core characteristics of children/adolescents with 22qDS, transcending performance features that are typical of individuals with low IQ.

MeSH terms

  • Adolescent
  • Child
  • Chromosome Deletion*
  • Chromosomes, Human, Pair 22*
  • Female
  • Humans
  • Intelligence*
  • Male
  • Mathematics*
  • Memory*
  • Neuropsychological Tests
  • Psychometrics
  • Reading*
  • Space Perception
  • Underachievement
  • Verbal Behavior
  • Visual Perception