DILLON, living with Duchenne.

Diagnosing Duchenne

Steps to Diagnosis

Duchenne is a rare disease with symptoms that can look like other, more common conditions, especially in the early stages. For these reasons, the path to diagnosis can often be prolonged and frustrating.

Every Duchenne family has a different story. Many receive a diagnosis only after months or years of doctors’ visits. Every child develops at his own pace, so a pediatrician may not take immediate action when your child is slow to sit, stand, or walk. However, over time, the delays seen in children with Duchenne become more apparent.

The diagnosis process often involves a series of steps to confirm Duchenne. Getting a confirmed diagnosis and understanding your child’s specific mutation is a critical step in arriving at the right course of treatment. If you or your family member have received a Duchenne diagnosis, learn more about Living with Duchenne.

Diagnosis: One Family's Journey

JB describes how her own intuition and concern for her son Charlie's development led eventually to a diagnosis of Duchenne muscular dystrophy.

Confirming a Duchenne Diagnosis

Although muscle damage starts at birth, the signs of Duchenne are typically first noticed in children at around 2.5 years of age. Duchenne is diagnosed at an average age of 5 years, a delay of 2.5 years after symptoms are usually first noticed. Confirming a Duchenne diagnosis earlier will help patients access and understand treatment options, potentially delaying disease progression. An earlier diagnosis will also enable family members to receive genetic counseling and take advantage of support networks.

Working with your child’s doctor, the first test will likely be a creatine kinase (CK) test, which involves a simple blood draw. CK is an enzyme in muscle cells that is released into the blood during muscle injury.

Trust your gut. Caregivers play an important role in diagnosing Duchenne–80% of the time when they express concerns about developmental problems, they are correct.

Having productive conversations with your child's or loved one's physician is very important, but may also be challenging. This guide to discussing a diagnosis can help you get more from important interactions with your doctor.

GUIDE TO DISCUSSING DUCHENNE

What Constitutes a High Creatine Kinase (CK) Level?

Although the normal range of CK levels varies with age and gender, CK levels in Duchenne are typically elevated 50- to 200-fold above normal levels, as shown in the table below.

If CK levels are high, your child’s doctor may refer you to a specialist for genetic testing. The genetic test helps to determine if your child has a genetic mutation associated with Duchenne to confirm the diagnosis.

Genetic Testing

Genetic testing is a laboratory procedure that looks closely at a sample of a person's DNA to assess whether they have genetic variants (changes in the gene) that are associated with a disease. Typically, it involves a blood or saliva sample.

In Duchenne, genetic testing can:

Confirm a diagnosis
Help patients and families understand their particular mutation
Identify the genetic variants associated with Duchenne so that care options can be considered
Provide information for identifying appropriate clinical trials for potential participation
Identify Duchenne carriers so that appropriate monitoring can be initiated
Identify other family members who may benefit from genetic testing, for example, siblings and other relatives

Different genetic testing methods are used to fully understand your child’s mutation (for example, deletion and duplication testing or genetic sequencing), and more than one test may be needed.

When Genetic Testing Is Inconclusive

In rare cases, genetic testing may be inconclusive. In these situations, the specialist may recommend a muscle biopsy to determine whether dystrophin is present or absent. If your family’s pediatrician becomes concerned that your child needs further testing, the first step may be a referral to a specialist—typically a pediatric neurologist or neuromuscular expert. These specialists will work to identify the cause of your child’s symptoms and may recommend additional testing. Only a doctor can accurately diagnose a child with Duchenne.

Guide For Genetic Testing

Speak with your child’s doctor about genetic testing to find out which genetic test is right for you and your family.

There are several no-cost genetic testing programs:

Decode Duchenne: provides no-cost genetic testing, interpretation, and counseling through PPMD and Revvity Omics.

Detect MD: provides no-cost genetic testing, interpretation, and counseling through Invitae.

Diagnostic Tests: A Closer Look

Graphic showing a table with a closer look at diagnostic tests. The CK test: What is measures - The amount of an enzyme, creatine kinase, in the blood. Creatine kinase typically leaks out of damaged muscle. High levels in the blood may suggest a muscle problem but cannot confirm Duchenne. What it entails - a blood test. When it is typically used - This is often the first step to see if genetic testing or a muscle biopsy is needed. Genetic testing: What is measures - Changes in genes. Genetic testing involves analyzing a person's DNA. It is used to see if there is a mutation in the dystrophin gene. If there is a mutation, it can tell you what kind of mutation it is. What it entails - a blood test. When it is typically used - If there are elevated CK levels or a suspected Duchenne diagnosis, a genetic test may confirm the genetic mutation that leads to Duchenne. Understanding your specific mutation may be necessary to consider possible treatment options.

Common steps many families experience include:

Observing signs and symptoms

Blood tests to determine enzyme levels (creatine kinase, or CK, test)

Referral to a specialist

Genetic testing

Muscle biopsy (if needed)

If you know or suspect that your child has developmental delays, talk with your child's doctor about a CK test. Our Guide to Genetic Testing may help you find the information you need.

Download the Guide