Abstract
<title>Abstract</title> <p>Intellectual disability (ID) frequently warrants genetic evaluation, and international guidelines strongly recommend exome or genome sequencing as a first- or second-tier test in children with congenital anomalies or ID. Yet families often navigate a prolonged diagnostic pathway, and the psychosocial and cultural factors that shape actual access remain fragmented across the literature. We synthesised qualitative, mixed-methods and quantitative evidence on the structural, sociocultural and psychosocial barriers and facilitators influencing access to and engagement with the genetic-evaluation pathway among individuals with ID, their families and caregivers. Following PRISMA 2020 and structured with the SPIDER framework, we searched PubMed and Scopus for empirical studies published between January 2020 and March 2026. Qualitative and mixed-methods studies were synthesised using thematic synthesis; quality was appraised with the MMAT 2018 and confidence in each finding with GRADE-CERQual, while quantitative studies of access and uptake were retained as context. Fourteen qualitative and mixed-methods studies were included and six quantitative studies retained as context, spanning Europe, Australia, the United States, Israel, Japan and Brazil. Documented barriers outnumbered facilitators; this asymmetry is interpreted partly as a feature of the searched literature rather than an established property of the field. Higher-confidence findings concerned the exclusion of people with ID from decisions about their own care and the psychosocial burden on caregivers, whereas the fewer facilitators — co-designed accessible information, clinician toolkits and integrated care models — were supported with lower confidence. Access is shaped by human, social and structural factors alongside technical ones, with confidence graded throughout.</p>