UCLA

This case series provides a detailed description of the coexistence of spinal muscular atrophy (SMA) type 1 and autism spectrum disorder (ASD) in children treated with disease-modifying therapies. Among 13 patients (2-7 years; mean age 4 years [SD 2 years], eight males), five met Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision criteria for ASD-a proportion substantially higher than expected and exceeding recent reports in SMA cohorts. These findings indicate that ASD may be underrecognized in this population and that traditional screening tools, such as the autism trait assessment, may fail to detect symptoms because of the severe motor and communicative limitations characteristic of SMA. Although all children demonstrated meaningful motor gains after treatment, those with SMA and ASD showed marked cognitive and adaptive impairments, particularly in communication, socialization, and daily living skills. The dissociation between motor improvement and neurodevelopmental outcomes underscores the need for tailored assessments and continuous behavioral surveillance. This report provides clinically relevant insights and highlights the importance of adapted diagnostic approaches for neurodevelopmental evaluation in SMA.