Introduction: Tuberous sclerosis complex (TSC) is a rare genetic multisystem disorder characterized by the widespread growth of benign hamartomas in multiple organ systems, leading to very diverse ...Show moreIntroduction: Tuberous sclerosis complex (TSC) is a rare genetic multisystem disorder characterized by the widespread growth of benign hamartomas in multiple organ systems, leading to very diverse (neuropsychiatric) manifestations, including autism spectrum disorder (ASD). This study aimed to examine the prevalence of clinically assessed ASD in children with TSC visiting a specialized TSC outpatient clinic. The influence of gender, age, intellectual functioning, and mutation type on a clinical ASD diagnosis was investigated. Secondly, the predictive value of using both a screening instrument and an observational assessment in relation to a clinical DSM-IV/-V ASD diagnosis in the group of children with TSC was examined. Methods: The data sample consisted of 110 children (50% male) between 1 and 17 years old (mean age = 9.65, SD = 4.61) diagnosed with a genetically and/or clinically confirmed diagnosis of TSC and a filled out ADOS and/or SRS. They were assessed as part of standard (mental) health care and longitudinal follow-up. The independent variables were gender, age, IQ/DQ, and mutation type, which associations with clinical ASD diagnoses were examined with Chi-Square Tests of Association or independent sample t-tests. The dependent variables were ASD classifications according to the Social Responsiveness Scale (SRS/SRS-2) scores, Autism Diagnostic Observation Schedule-second edition (ADOS-2) scores, and DSM-IV/-V diagnoses. Results: A clinical ASD prevalence rate of 52.7% was found, substantially higher than in the general population. Children with a clinical ASD diagnosis had significantly lower intelligence scores (p = .01). No gender, age, or mutation type effects were found. The combined use of screening and observational- based classifications showed the highest positive predictive value for DSM-IV/-V ASD diagnosis. Discussion: The results showed a substantially higher ASD prevalence rate compared to the general population, underlining the importance of ASD assessment in children with TSC. Furthermore, these results highlighted the relevance of using both a screening instrument and an observational assessment to accurately classify children with TSC as having ASD. A better ASD prediction and classification may lead to earlier diagnosis and appropriate, personalized interventions, potentially alleviating some of the burden for both patients and their families or caregivers.Show less
