Parents with HNPCC have a 50% chance of passing the genetic mutation on to each child. It is also important to note, that deleterious mutation in one of MMR genes alone is not sufficient to cause cancer, but that rather further mutations in other tumour suppressor genes need to occur. Diagnosis
A diagnosis of Lynch syndrome is applied to people with a germline DNA mutation in one of the MMR genes (MLH1, MSH2, MSH6, and PMS2) or the EPCAM gene, identified by genetic testing. Candidates for germline genetic testing can be identified by clinical criteria such as the Amsterdam Clinical Criteria and Bethesda Guidelines, or through tumor analysis by immunohistochemistry(IHC), or microsatellite instability (MSI) testing. In the US, professional societies recommend testing every colon cancer for MSI or IHC as screening for Lynch syndrome, but this is not always performed because of cost and resource limitations. Genetic testing is commercially available and consists of a blood test. Immunohistochemistry
Immunohistochemistry (IHC) is a method that can be used to detect abnormal mismatch repair (MMR) protein expression in tumours that are associated with Lynch syndrome. While it is not diagnostic of a Lynch syndrome, it can play a role in identifying people who should have germline testing. Two methods of implementation of IHC testing includes age-based testing and universal testing for all people. Currently, there is no widespread agreement regarding which screening method should be used.
Rasmussen syndrome is a condition characterized by multiple skin growths called trichoepitheliomas. See also
List of cutaneous neoplasms associated with systemic syndromes
List of cutaneous conditions


== References ==