There are many different forms of muscular dystrophy. The most widely recognized type is called Duchenne muscular dystrophy, or DMD. This type typically only affects boys, and causes very severe symptoms.

Here’s why males are much more likely to get the disease. DMD is caused by a gene change carried on the X chromosome. Women have two X chromosomes. So, as long a one of their two X chromosomes is normal, they are less affected if they “carry” the genetic change. But female “carriers” do have a 50% chance of passing the genetic change to a child. 

But males only have one X chromosome (and one Y chromosome). So if they inherit an X chromosome with the gene change, they will get the full disease. The Y chromosome doesn’t matter in this situation.

Women that "carry" the genetic change on one X chromosome will not have the full disease. And often have no symptoms during child-bearing years. Some female “carriers” may develop mild symptoms, especially as they get older.

Other types of muscular dystrophy may affect boys or girls, and may range from mild to severe in terms of symptoms. There are different patterns of inheritance for different types of muscular dystrophy. In some types, everyone who carries the genetic change will have symptoms. In other types, a carrier could be unaffected. But still pass along the genetic change to a child.

The first step is to find out what type of muscular dystrophy runs in your family. If you don’t know, then one or more of your family members with muscular dystrophy should be seen by a neurologist who has experience in "neuromuscular disorders." Doctors can perform a variety of tests. Start by discussing your question with your primary care doctor. He or she may need to give you a referral to a specialist.

If you know the type of muscular dystrophy in your family, then you may want to get genetic testing. This helps determine if you carry the genetic change for muscular dystrophy.  A medical geneticist or neurologist can perform this test. You may also need to check if your insurance covers genetic testing (note that testing to see if you carry the gene change is not always covered by insurance).

If you pursue genetic testing, the doctor would first test a family member with muscular dystrophy using a blood test to look for specific genetic changes. If the test can identify those changes, then other family members could take the same test to see if they carry the same genetic change.

It’s important to get genetic counseling before and after the test. That way, you come away with a good understanding of what the test results mean in your specific situation.