DMD/BMD Exon Analysis Tool
Interpreting genetic test results for Duchenne vs Becker muscular dystrophy can be overwhelming for families. Our DMD or Becker? Exon Check Tool helps you quickly analyze dystrophin gene exon deletions or duplications and understand whether a mutation is consistent with Duchenne or Becker. Built around the reading frame rule, this tool simplifies complex genetic data into clear, actionable insights.
Families often receive a genetic report listing exon deletions or duplications, but understanding whether these changes lead to Duchenne muscular dystrophy (DMD) or Becker muscular dystrophy (BMD) is not always straightforward. Learn More: Differences between DMD and BMD.
The key factor is whether the mutation disrupts the reading frame of the dystrophin gene. This tool helps bridge that gap by translating exon numbers into meaningful interpretation—saving time, reducing confusion, and supporting informed discussions with clinicians.
Genetic testing can identify your/your child’s specific mutation. If you/your child need genetic testing, please talk with your doctor, genetic counselor.
The dystrophin gene, which helps maintain muscle structure in our bodies, can be likened to a train carriage made up of 79 pieces. If one or more of these train carriages are missing, you can predict that the locomotive will carry less weight. This is exactly how dystrophin, the longest gene in our bodies, works. Depending on where the carriages are missing, dystrophin production decreases or stops altogether.
The difference between Duchenne and Becker largely depends on how a mutation affects dystrophin production.
- Out-of-frame mutations → typically associated with Duchenne muscular dystrophy
- In-frame mutations → more often linked to Becker muscular dystrophy
This principle is known as the reading frame rule in DMD. However, exceptions exist, and clinical evaluation is always required. Our tool applies this rule to help you better understand your results.
DMD or BMD? Exon Check Tool
If you know that your or your child’s genetic mutation involves a dystrophin gene exon deletion, this educational tool can help you understand whether you may be a candidate for exon skipping therapy in Duchenne muscular dystrophy (DMD). By analyzing exon changes and applying the reading frame rule, the tool supports clearer genetic test interpretation for Duchenne and Becker muscular dystrophy.
If you are unsure about the mutation type, or if your genetic test results for muscular dystrophy are difficult to understand, we strongly recommend consulting a pediatric neurology, genetics, or neuromuscular disease specialist for accurate evaluation and guidance.
Instructions: Based on the genetic test report, you can identify which exons are deleted in your child. Enter the first and last exon numbers from the genetic test results into the fields below. If there is a single exon deletion, enter the same number in both fields. Example: 11-11, 23-25, 45-51.