Engaging children, adolescents and young adults living with rare diseases as research partners: practical considerations for meaningful involvement.

Engagement of patients has become increasingly recognized as an important principle in medical and health research and development. However, the engagement of young people affected by a rare disease- including children, adolescents, and young adults - has lacked consistent practical guidance that is structured, developmentally appropriate, and ethically grounded. Without clearer practical considerations, researchers may have limited guidance to effectively include this crucial population in ways that respect their evolving autonomy, accommodate diverse contexts, and ensure meaningful impact. This is especially important in rare disease research, where the majority of affected people are children. To address this gap, the International Rare Diseases Research Consortium convened a Working Group on Young People's Engagement, comprising 16 international experts. The group included two young people alongside academic and industry researchers, patient advocates, and clinical specialists with experience working directly with youth. The Working Group reviewed core requirements for engaging young people in research and examined case studies illustrating diverse engagement approaches. Drawing on existing patient engagement frameworks, the group developed expert-informed practical guidance, including a checklist, to support researchers in considering appropriate engagement strategies across developmental stages and research contexts. Strengthening the engagement of young people in rare disease research may help ensure that different types of research, including innovation development, shaping study design, outcome measures and policy decisions, are meaningful, relevant, and reflective of their lived experiences.