Cognitive profile in adult women with turner syndrome: IQ split and associations with ADHD and ASD.

Introduction: The behavioural phenotype in Turner syndrome (TS) is associated with an uneven cognitive profile and social and executive difficulties. Still, studies in adult populations of TS are scarce, and the interactions between different behavioural domains are unclear. The aim of this study was to examine the cognitive profile in relation to measures of ADHD and ASD in a Swedish sample of 30 adult women with TS.

Methods: Standardized psychological tests and questionnaires were used for behavioural assessments in a sample of adult women with a diagnosis of TS (n = 30). Both frequentist and Bayesian statistics were applied.

Results: The cognitive profile was characterized by a verbal > non-verbal intelligence quotient (IQ) split, and 77% of the sample displayed a split exceeding cut-off for clinical significance. Symptoms on screening measures reaching thresholds for ADHD were reported in two of the 30 participants (7%) and thresholds for autism spectrum disorders (ASD) in one participant (3%). Bayesian statistics gave substantial evidence for no association between the IQ split and symptoms of ADHD/ASD.

Conclusions: These results show that the TS phenotype in adulthood is associated with a clinically significant uneven cognitive profile, and particular impairments in integrative executive functions.