Rare diseases are defined by their low prevalence — often fewer than 1 in 2,000 people — yet collectively affect hundreds of millions worldwide. These conditions are frequently genetic, complex, and under‑researched, with many patients facing long diagnostic journeys and limited treatment options. Rare Disease Day, observed every year on 28 February, raises global awareness of rare conditions and advocates for improved diagnosis, care, research, and support for affected individuals and families. The date itself is symbolic, chosen because February 29 — the “rarest day” — highlights the rarity of the diseases it represents. The IMPC is proud to celebrate Rare Disease Day 2026, showcasing its contribution to rare disease research through systematic mouse genetics.
Mouse models are uniquely valuable in rare disease research because mice share substantial genetic and physiological similarity with humans; targeted gene disruption can reveal the biological consequences of mutations linked to human disorders. IMPC’s standardized phenotyping pipelines identify disease‑relevant phenotypes systematically, helping researchers validate gene–disease associations, explore underlying mechanisms, and prioritise targets for therapy.
IMPC member laboratories have collaborated with the European Joint Programme on Rare Diseases (EJP RD) and the Rare Diseases Models & Mechanisms – Europe (RDMM‑Europe) network. Through these initiatives, IMPC labs are selected to work on mouse models for specific rare diseases, connecting clinicians identifying potential disease genes with researchers who can functionally validate them — a crucial step in moving from gene discovery to understanding disease biology and developing therapies.
Together, these efforts highlight how mouse genetics accelerates rare disease research, improves diagnosis, and opens new avenues for treatment of some of the most challenging human conditions.
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