Need to consider test results in the context of mutation variability , gene penetrance , and gene expressivity . Mutations can be in the same or different genes. Mutation tests often test for only the most common mutations. Current tests are for about 70 common mutations. Incomplete penetrance - an individual with a mutation may never get the disease.
Some mutations are completely penetrant - an individual with the mutation always gets the disease.
Severity can vary widely for some diseases, and few specific mutations have been correlated with the severity of their expression in an individual. The most common mutation in Caucasians has been associated with pancreatic insufficiency, but few other correlations have been made of disease gene mutations and their particular expression. Available Treatment Options Few treatments or preventive strategies exist for patients testing positive for most gene tests. Unfortunately, knowledge of a gene mutation alone is insufficient information for researchers trying to devise intervention strategies. Experts recommend that even children at high risk be screened for mutations in the APC gene associated with FAP, because they can be monitored more frequently for growths and effective preventive surgical options can be chosen.