• This case contributes to the limited literature on the cooccurrence of FHS and ASD.
• A de novo SRCAP variant highlights the complex genetic basis of ASD.
• This case shows the need for detailed genetic evaluations in atypical ASD cases.
Introduction: The genetic basis of autism spectrum disorder (ASD) is highly heterogeneous and continues to be elucidated through syndromic associations. Floating-Harbor Syndrome (FHS) is a rare genetic disorder caused by SRCAP mutations and is characterized by short stature, expressive language delays, and distinct craniofacial features. This report aims to present the diagnostic process and clinical challenges of a child diagnosed with both FHS and ASD.Case: A 9-year-old boy presented with social communication difficulties, restricted interests, and sensory hypersensitivity. Psychometric testing demonstrated average intellectual functioning (IQ: 94), while behavioral assessments revealed significant hyperactivity and behavioral dysregulation, in addition to severe autism as measured by the Childhood Autism Rating Scale (CARS). Based on DSM-5 criteria, he was diagnosed with ASD. Persistently elevated amylase and lipase levels prompted genetic evaluation, which confirmed FHS with an SRCAP mutation.Discussion: This case underscores the diagnostic challenges of differentiating syndrome-specific features from true comorbid ASD when overlapping symptoms such as language delay and behavioral problems are present. These findings highlight the importance of comprehensive psychiatric and genetic evaluation in children with complex developmental profiles, and highlights the need for systematic screening for neurodevelopmental disorders in rare genetic syndromes.
Keywords: Autism Spectrum Disorder, case report, comorbidty, Floating-