Laboratory tests used during diagnosis

To find out if someone has Fabry disease, tests need to be done. These tests could include:

  • Enzyme activity tests

One of the tests used to further investigate the suspicion of someone having Fabry disease is to analyse alpha-GAL A enzyme activity from a blood sample. In people with Fabry disease, the activity level of this enzyme is typically (much) lower than people without Fabry disease. Testing enzyme activity can also be done on other sample types such as skin cells called fibroblasts or ‘Dried Blood Spots’ (DBS) where small amounts of blood are dried onto filter paper. The levels of enzyme activity can be a good indicator if the disease is present or not. However, because of the nature of the disease and how it is inherited (via the X-chromosome), in some cases this test in not sufficient on its own. Genetic tests are often performed to confirm or exclude the diagnosis of Fabry disease.

  • Genetic tests

Genetic tests can be performed to confirm or exclude the presence of a Fabry disease causing mutation, as well as to find out what genetic defects are causing the disease. This is called ‘genotyping’ and can give useful genetic information to doctors.
A person with Fabry disease and their family may be offered counselling at this stage so they can learn about how this will impact their lives.

Because Fabry disease can affect different organ systems, doctors may perform other tests and examinations to see how Fabry disease is affecting these different parts of the body.

People with Fabry disease may manifest overt Fabry disease symptoms during the first decades of life but an accurate diagnosis is very important so they can be monitored for symptoms over time. Also a definitive diagnosis can help to find any other family members who may have the disease and need treatment.