Comparative language performance in children and adolescents with 22q11.2ds syndrome and down syndrome.

Genetically defined neurodevelopmental syndromes provide a framework for examining constraints on language development. This study compared language performance in children and adolescents with 22q11.2 deletion syndrome (22q11.2DS; n = 40) and Down syndrome (DS; n = 40), matched for age and nonverbal cognitive ability, aged 6-16 years. Standardized assessments included the Clinical Evaluation of Language Fundamentals (CELF-5) and the BLOC-C to evaluate multiple receptive and expressive language domains. Group differences, effect sizes, and associations with age were analyzed to characterize syndrome-specific profiles. Children with 22q11.2DS demonstrated relatively stronger receptive vocabulary and syntax alongside weaker morphosyntactic and pragmatic skills, with vocabulary showing moderate positive associations with age. In contrast, the DS group exhibited generally lower performance across domains, with pronounced difficulties in morphosyntax and limited age-related gains. These findings highlight differences in overall level of performance and relative strengths within a globally impaired profile across syndromes and emphasize the value of multi-dimensional assessment in capturing both age-related patterns and vulnerabilities.