INFORM RARE is a CIHR SPOR-funded innovative clinical trials network to evaluate new and existing therapies for children with rare inherited diseases. Our first three trials focus on spinal muscular atrophy (SMA), mucopolysaccharidoses (MPS), and phenylketonuria (PKU). Our program of research is co-designed by more than 65 investigators, including patients and families, health care providers, policy-makers, methodologists, and research ethicists. We are developing cross-cutting methods in the design of registry-based randomized trials, including developing longitudinal core outcomes-oriented patient registries to serve as a platform for trials, and addressing ethical issues related to the sharing of patient-reported outcomes between research and clinical care. We have a strong multilayered patient engagement strategy that engages both parents and youth.