Getting Diagnosed

Steps to a DMD diagnosis.

On average, obtaining a confirmed Duchenne diagnosis takes about 2.5 years from the time symptoms are first noticed. Diagnosis is the vital first step in managing Duchenne, so it’s important to obtain a diagnosis as early as possible—before additional muscle damage occurs.

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Deletion of exons 52

Common steps to a Duchenne diagnosis.

Parents, caregivers, or teachers

If you or others are seeing telltale signs of Duchenne, such as large calves or Gowers' Maneuver, trust your gut and check in with your child’s doctor. See the symptoms of Duchenne.

Family doctor or pediatrician

Ask the doctor for a creatine kinase, or CK, blood test. This is a simple, highly accurate test for indicating muscle damage that can result from Duchenne. A CK test can’t confirm Duchenne or identify the mutation—only a genetic test can. Learn more about genetic testing.

Pediatric neurologist or neuromuscular specialist

Genetic testing will determine if a mutation is present on the dystrophin gene that would indicate Duchenne. It can also identify the type of mutation—which is important for determining potential clinical trial participation or therapy options. Explore sample test results.


These are the common steps to a diagnosis, but your path may be different. The important things are arming yourself with information on tests that can diagnose Duchenne and talking to your doctor as soon as your child displays the signs. 


We’ve developed a Doctor Discussion Guide to help you start that important conversation. Get a personalized guide.

Why a timely diagnosis matters.

With Duchenne, symptoms such as muscle weakness and loss of mobility are progressive, and unfortunately, muscle damage is irreversible. The earlier you know the diagnosis, the sooner you can start the conversation about disease management with your child's doctor. You’ll know your options after genetic testing that will confirm Duchenne and identify the specific mutation in the dystrophin gene. Learn more about treatment with EXONDYS 51.

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Related FAQs

Where do I get a genetic test?

If your child has been diagnosed with Duchenne, you can request a genetic test through your child’s doctor. Once you have the results, your doctor or a genetic counselor can interpret them for you. Find out more about genetic testing for Duchenne.

We have a genetic test. How do I know if my child can be treated with EXONDYS 51?

A doctor will need to interpret the test results to consider appropriate treatment options. Learn more about deletions.



WHAT IS EXONDYS 51 (eteplirsen)?

EXONDYS 51 is used to treat Duchenne muscular dystrophy (DMD) in patients who have a confirmed mutation in the dystrophin gene that can be treated by skipping exon 51. EXONDYS 51 was approved under accelerated approval. Accelerated approval allows for drugs to be approved based on a marker that is considered reasonably likely to predict a clinical benefit. EXONDYS 51 treatment increased the marker, dystrophin, in skeletal muscle in some patients. Verification of a clinical benefit may be needed for EXONDYS 51 to continue to be approved.

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Allergic reactions, including wheezing, chest pain, cough, rapid heart rate, and hives have occurred in patients who were treated with EXONDYS 51. Seek immediate medical care if signs and symptoms of allergic reactions occur.

Side effects that happened at least 25% more often in 8 patients treated with EXONDYS 51 by intravenous infusion than in 4 patients treated with an inactive intravenous infusion were problems with balance (38%, 0%), vomiting (38%, 0%), and skin irritation (25%, 0%). The most common side effects were problems with balance and vomiting.

The most common side effects seen in greater than 10% of patients receiving EXONDYS 51 (N=163) in other clinical trials were headache, cough, rash, and vomiting. 

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit or call 1-800-FDA-1088. You may also report side effects to Sarepta Therapeutics at 1-888-SAREPTA (1-888-727-3782).

Please see the full Prescribing Information for EXONDYS 51 (eteplirsen).