Importance and Potential of Rare Disease Research in Pediatric Rheumatology and Beyond: Pushing Frontiers.

Although individually occurring in less than 1 in 2,000 people, cumulatively, more than 7,000 rare diseases affect approximately 6% of the population worldwide. Children and young people are disproportionally challenged in number and severity, which may be explained by the large proportion of genetic conditions among rare diseases (70%-80%). Indeed, an estimated 30% of children with rare diseases do not survive past their fifth birthday. Because rare diseases are frequently missed or diagnosed with a delay of several years and <5% of rare diseases have a licensed treatment, the impact of rare diseases on the indivual affected (independent of age) and wider society is significant. To address these challenges sufficiently, rare disease expert centers combining research activity with patient care are needed to develop diagnostic tests, prognostic tools, and new treatments. This expert-driven approach promises expedited diagnosis and efficacious treatment and care. Although restricted by chronic underfunding, rare disease research keeps delivering new exciting treatment options and technologies, some of which have revolutionized care not only in niche areas of medicine but also common diseases (the use of interleukin-1 blockers in gout or COVID-19-associated hyperinflammation, etc). However, rare disease research and care will only be successful in collaborative, mutidisciplinary and multiprofessional teams that involve patients and families as equal partners and span across institutional and national borders. Lastly, the use of state-of-the-art computational approaches to share knowledge and associate molecular with clinical phenotypes, treatment responses, and disease outcomes will amplify our ability to serve patients and the society.