The Incidence of Autism Spectrum Disorder Among Children With STXBP1-Related Disorders

STXBP1-Related Disorders (STXBP1-RD) is a rare genetic condition that is estimated to occur in 1 in 30,000 births and was first identified in 2008 (Saiitsu et al, 2008). Features include seizures, developmental delays and shared characteristics with autism spectrum disorder (ASD); however, ASD may be underreported in this population. This study aims to define the prevalence of ASD in individuals with STXBP1-RD. The secondary aim is to apply these findings to occupational therapy (OT) practice by presenting the implications for clinical evaluation and intervention. This study utilizes a retrospective descriptive design. Participants were identified via a convenience sample through the STARR study at the Children’s Hospital of Philadelphia (CHOP), which is the largest natural history study of STXBP1-RD. 52 individuals with STXBP1-RD were included in this sample. Prior ASD diagnoses were identified through medical record review while assessments for ASD were completed by developmental pediatricians. Results showed that 46% of STXBP1-RD patients had prior ASD diagnoses. Upon evaluation, 84.6% of patients were at risk for ASD per a CARS-2 assessment. Of these patients, 45% scored at a mild-moderate level of behaviors related to ASD and 55% scored at a severe level of behaviors related to ASD. Following the STARR evaluation, 62% of patients were diagnosed with ASD. The results from this study indicate that ASD is underdiagnosed in individuals with STXBP1-RD, with previous estimates of ASD or autistic features falling between 17-42% (Stamberger et al. 2016; Stamberger et al. 2022; Thalwitzer et al. 2023). Implications from this study point towards the need for early and comprehensive ASD evaluations in individuals with STXBP1-RD. These findings will impact OT practice in that the social and behavioral challenges seen in STXBP1-RD will be better understood. This will improve access to appropriate services and caregiver recommendations to facilitate occupational engagement.

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