There are currently between 6000 and 8000 known rare diseases worldwide. A disease is considered rare if it affects less than five in 10 000 people. Because they are so rare, it is often difficult for healthcare providers to detect these diseases early and offer appropriate treatment. Various tests are used to diagnose rare diseases, including genetic tests to determine hereditary factors. The Swiss Atlas of Healthcare contains analyses on the frequency of genetic screening and tests on congenital metabolic disorders, and total tests.