Transition From Children's to Adults' Healthcare for Youth With (Genetic) Intellectual Disabilities: An ERN-ITHACA Guideline.

Background: For young people with rare genetic neurodevelopmental disorders associated with intellectual disabilities, the transfer from paediatric to adult healthcare providers is often complicated. The European Reference Network ERN-ITHACA (Intellectual disability, TeleHealth, Autism and Congenital Anomalies) on Rare Congenital Malformations and Rare Intellectual Disability aims to improve this transition through the development of a guideline.

Method: Population-specific recommendations for the optimal transition to adult healthcare were developed by an interdisciplinary consortium, representing clinical, scientific and lived experience experts from nine European countries. Recommendations of the 2016 National Institute for Health and Care Excellence (NICE) guideline 'Transition From Children's to Adults' Services for Young People Using Health or Social Care Services' (NG43) were adapted, based on a literature review, expert opinion and lived experiences gathered through a survey, focus groups and discussions with self-advocates. A consensus meeting was held in Gdańsk, Poland, in October 2024.

Results: NICE guideline recommendations were adopted or adapted to the target population where necessary. New recommendations were formulated regarding the involvement of and assistance for young people and their families/caregivers, the coordination of interdisciplinary care, the role of centres of expertise, recommended interventions and psychosocial support.

Conclusions: Planned, coordinated, specialised, individualised and interdisciplinary healthcare is required to support young people with (genetic) intellectual disabilities. Active collaboration between healthcare providers, researchers and individuals with lived experience is essential both to improve current healthcare and to build a stronger evidence base for successful transition interventions going forward.