Source:http://linkedlifedata.com/resource/umls/id/C0600498
MSH: The apparent tendency of certain diseases to appear at earlier AGE OF ONSET and with increasing severity in successive generations. (Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed),NCI: A phenomenon in which the signs and symptoms of some genetic conditions tend to become more severe and/or appear at an earlier age as the disorder is passed from one generation to the next. Huntington disease is an example of a genetic disorder in which the biological mechanism for this phenomenon has been well documented. In other cases, it may be due to factors such as increased surveillance or other nongenetic causes.