Tests/Screens
There are two reliable tests available that will help doctors confirm a preliminary diagnosis of Duchenne MD.
1. Creatine Kinase
The body creates an enzyme called “creatine kinase” (also known as CK) that normally lives inside muscles. When muscles are functioning normally, CK levels in the bloodstream are relatively low. But when muscles are damaged, the muscle cells split open, causing their contents to spill out into the bloodstream. This creates a rise in the levels of CK in the blood. Measuring CK levels may verify that there has been muscle damage and may indicate more muscle damage to come.
2. Muscle Biopsy/DNA
Once a CK test comes back showing high levels of the enzyme in the blood, conclusions can be made that muscles are likely damaged. But a CK test alone cannot diagnose Duchenne MD. In order to determine the cause of the muscle damage, doctors will usually perform a muscle biopsy. This requires a doctor to surgically remove a small sample of muscle and examine it closely to determine what is happening inside the cells. This test is the most reliable way to diagnose Duchenne MD, and distinguish it from the other inflammatory disorders, and from other Muscular Dystrophies.
DNA testing (using blood cells or muscle cells) remains the best way to obtain exact genetic information leading to a conclusive Duchenne MD diagnosis. In the future, as this type of testing becomes more commonplace, it will lead to faster diagnosis of all Muscular Dystrophies.
DNA
DNA is supremely important. It determines how our bodies are made and how they work. It is a simple molecule in terms of its construction, and a complicated one because of the huge quantity of information it stores. DNA lies at the heart of Duchenne MD. As we learn more about DNA, we will likely find new ways to treat and cure Duchenne MD.
DNA testing is generally performed using a tool called a “PCR”, an acronym for "polymerase chain reaction". Essentially this is a way to make large quantities of DNA from a small sample so that multiple tests can be performed
