Acromegaly

Because acromegaly is most often caused by a randomly developing tumor when a person is an adult, there is no newborn screening or testing for acromegaly.

If a person begins to develop the physical features of acromegaly (enlarged hands and feet, changes in facial features, etc.) they will likely do two different things to help make the diagnosis.

The first thing is some blood work. Acromegaly is caused by elevated levels of growth hormone (GH). Because levels of growth hormone fluctuate in every person, taking blood at one random time is not enough to make a diagnosis. Therefore, in order to get a more accurate result, a glucose tolerance test is used. This test has a person drink 75-100mg of glucose (essentially sugar water). In people without acromegaly, the GH level should drop to a very low level. In people with acromegaly, this lowering does not occur.

The second step is some imaging of the brain to look at the pituitary gland located deep in the center of the brain. This is because most people who develop acromegaly do so because of a benign (non-cancerous) tumor that is growing on the pituitary gland. MRI scans are preferred to look at the pituitary, but CT scans can also be used. If a tumor is not found on the pituitary, them more imaging of the body needs to be done. This is because about 5% of the time, people with acromegaly develop a tumor in other places of their body that can also cause acromegaly.

Because most cases of acromegaly are the result of random events, family members of recently diagnosed individuals do not routinely need tested. However, if they have or develop similar symptoms then, it might be a good idea to have them evaluated by a doctor. Also, in rare situations, acromegaly can run in families. We usually suspect this when children or teenagers are affected. In that situation, it may be more likely for other people in the family to also develop acromegaly. In some individuals with acromegaly an AIP gene change is found that causes that person to be at increased risk to develop a tumor. Based on the type of tumor, the age the tumor was diagnosed in a family member, and other factors, genetic testing of the AIP gene may be useful to help identify other family members who are at increased risk to develop acromegaly. Your doctor can help you understand if you are at increased risk for having a genetic change in the AIP gene and may want to pursue genetic testing. Your doctor may also want to refer you to a medical geneticist or genetic counselor to discuss your risk further. A medical geneticists can be found by asking your doctor for a referral or looking on the American College of Medical Geneticists website. Genetic counselors can be found on the National Society of Genetic Counselors website.