There are estimated to be between 5000 to 8000 rare diseases, defined as a life-threatening or chronically / debilitating disease that affects five people or fewer in 10,000. Examples include Cystic fibrosis, Duchenne muscular dystrophy and Marfan syndrome. The majority of rare diseases have a genetic origin. Of the more than 3 million people in the UK who may have a rare disease, half of new cases are identified in children. Because these diseases are so rare, there can be long delays before a final diagnosis is obtained, which can have serious consequences for the health of patients as they may receive sub-optimal care and support. Genomics offers the potential for much faster and cheaper diagnosis of genetically-based rare diseases.
The UK has developed a Strategy for Rare Diseases which seeks to address, among other issues, this delay in diagnosis. Since no system has yet been developed to measure or monitor changes in the time of diagnosis for most rare diseases, PIRU was asked to determine whether a system can be developed for monitoring the "diagnostic odyssey" of rare diseases, that is, the medical journey travelled by patients towards a correct diagnosis.