Mutations in the human genome can cause thousands of rare but nonetheless serious diseases impacting hundreds of thousands of Canadians (www.raredisorders.ca). The identification of a gene mutation that causes a human disease is a breakthrough discovery, but to realize benefit to patients, subsequent studies on the basic function of the gene and the functional consequences of the specific gene mutations in a biological context are required. Most rare diseases are not the focus of a research laboratory, which greatly limits our ability to discover new effective therapies. Insight into most human rare diseases can be informed through analysis of the equivalent genes and pathways in an experimental organism, because nature reuses the same building blocks to construct organisms as different as yeast, worms, flies, fish, mice and humans. It is on this backdrop that this team will establish a national network, Canadian “Rare Diseases: Models and Mechanisms” (RDMM), that will mobilize the entire Canadian biomedical community of laboratory scientists and clinicians to communicate and connect; integrate and share their resources and expertise; and, work together to provide functional insights into newly discovered rare disease genes.