What do the results mean?

The results of genetic tests are not always straightforward, which often makes them challenging to interpret and explain. When interpreting test results, your doctor considers your medical history, family history and the type of genetic test that was done.

A positive test result means that the laboratory found the expected changes in the prion gene. Depending on your health status, this result may confirm a diagnosis, indicate that you are a carrier of the genetic mutation or identify an increased risk of developing CJD in the future. A positive test result may have implications for blood relatives too.

A negative test result means that the laboratory did not find an abnormal change (mutation) in your gene. This negative test result indicates that you do not have genetic prion disease, because you do not have a genetic mutation in the prion protein gene.

In some rare cases, an inconclusive test result sometimes occurs because everyone has common, natural variations in their DNA, called polymorphisms, which do not affect your health. Sometimes is it difficult to know if a variation in a person's DNA is a very rare (uncommon) polymorphism or a mutation (a change in the DNA that will cause genetic prion disease). If the genetic test finds a change in DNA that has not been associated with a disorder in other people, it can be difficult to tell whether it is a rare, natural polymorphism or a disease-causing mutation.

article_image_comp: