RESUMO
PURPOSE: Rare genetic neurodevelopmental disorders associated with intellectual disability require lifelong multidisciplinary care. Clinical practice guidelines may support healthcare professionals in their daily practice, but guideline development for rare conditions can be challenging. In this systematic review, the characteristics and methodological quality of internationally published recommendations for this population are described to provide an overview of current guidelines and inform future efforts of European Reference Network ITHACA (Intellectual disability, TeleHealth, Autism, and Congenital Anomalies). METHODS: MEDLINE, Embase, and Orphanet were systematically searched to identify guidelines for conditions classified as "rare genetic intellectual disability" (ORPHA:183757). Methodological quality was assessed using the Appraisal of Guidelines, Research, and Evaluation II tool. RESULTS: Seventy internationally published guidelines, addressing the diagnosis and/or management of 28 conditions, were included. The methodological rigor of development was highly variable with limited reporting of literature searches and consensus methods. Stakeholder involvement and editorial independence varied as well. Implementation was rarely addressed. CONCLUSION: Comprehensive, high-quality guidelines are lacking for many rare genetic neurodevelopmental disorders. Use and transparent reporting of sound development methodologies, active involvement of affected individuals and families, robust conflict of interest procedures, and attention to implementation are vital for enhancing the impact of clinical practice recommendations.