Behavioral Phenotypes of Omani Children with Autism Spectrum Disorder

Background: Autism spectrum disorder (ASD) is characterized by substantial phenotypic heterogeneity, which can complicate clinical formulation and intervention planning. Despite increasing epidemiological research on ASD in the Sultanate of Oman, systematic behavioral variation among Omani children with ASD has not been reported in the published literature. This study aimed to explore patterns of behavioral profiles in an Omani clinical cohort using multidimensional measures of repetitive behavior and social functioning. Methods: We conducted a cross-sectional study of 205 children with DSM-5-confirmed ASD (mean age 5.3 ± 2.6 years; 80.5% male) attending specialist services in Muscat, Oman. Parents completed the Dimensional Assessment of Repetitive Behavior (DARB) and the Stanford Social Dimensions Scale (SSDS), two multidimensional parent-report instruments. Two-step cluster analysis was used to explore clusters representing a continuum of behavioral characteristics. Verbal and non-verbal children were also compared across DARB and SSDS dimensions. Results: A two-cluster solution (silhouette coefficient = 0.40, indicating weak-to-fair separation) described a severity gradient: a higher-severity cluster (n = 59, 28.8%) with elevated scores across all eight DARB subdomains and lower scores across all five SSDS dimensions, and a lower-severity cluster (n = 146, 71.2%). Clusters did not differ significantly on the demographic variables examined, including consanguinity (p = 0.489). Among verbal children (n = 126), social motivation, affiliation, expressive communication, and social recognition scores were higher than among non-verbal children (n = 79). Non-verbal children demonstrated greater sensory-motor stereotypy. Conclusions: This exploratory study provides an initial characterization of behavioral variation among children with ASD in an Omani clinical cohort. The clustering results suggest a continuum of behavioral characteristics, together with differences associated with verbal status, highlights clinically meaningful heterogeneity within the Omani ASD population. These findings are hypothesis-generating and may help inform future research on individualized assessment and intervention in Oman and the wider Arab Gulf region.