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As the GREGoR Consortium website grows, we will add key terms and definitions to this glossary. If you encounter a word you’re curious about, please check here for more information!

  • Diagnostic odyssey - the time between onset of a condition in an individual and a confirmed diagnosis in an individual with a rare disease.
  • Gene discovery - the process of identifying the gene or genes responsible for a particular condition.
  • Mendelian disease - any condition which shows Mendelian inheritance. This means a condition which is caused by variants in a single gene. Inheritance patterns of Mendelian disease are autosomal dominant, autosomal recessive, or X-linked. 1
  • Rare disease - a condition that affects fewer than 200,000 people in the US. There may be as many as 7,000 rare diseases. The total number of Americans living with a rare disease is estimated at between 25-30 million. Rare diseases currently affect 3.5% - 5.9% of the worldwide population. It is estimated that 72% of rare diseases have a genetic cause. 2,3