Testing
Since the early 2000s genetic testing that measures the size of the D4Z4 deletions on 4q35 has become the preferred mechanism for confirming the presence of FSHD. As of 2007, this test is considered highly accurate but is still performed by a limited set of labs in the US, such as Athena diagnostics under test code 405. However, because the test is expensive, patients and doctors may still rely on one or more of the following tests, all of which are far less accurate and specific than the genetic test:
- Creatine kinase (CK) level: This test measures the Creatine kinase enzyme in the blood. Elevated levels of CK are related to muscle atrophy.
- electromyogram (EMG): This test measures the electrical activity in the muscle
- nerve conduction velocity (NCV): This test measures the how fast signals travel from one part of a nerve to another. The nerve signals are measured with surface electrodes (similar to those used for an electrocardiogram), and the test is only slightly uncomfortable.
- muscle biopsy: Through outpatient surgery a small piece of muscle is removed (usually from the arm or leg) and evaluated with a variety of biochemical tests. Researchers are attempting to match results of muscle biopsies with DNA tests to better understand how variations in the genome present themselves in tissue anomalies.
Read more about this topic: Facioscapulohumeral Muscular Dystrophy
Famous quotes containing the word testing:
“Traditional scientific method has always been at the very best 20-20 hindsight. It’s good for seeing where you’ve been. It’s good for testing the truth of what you think you know, but it can’t tell you where you ought to go.”
—Robert M. Pirsig (b. 1928)
“Bourbon’s the only drink. You can take all that champagne stuff and pour it down the English Channel. Well, why wait 80 years before you can drink the stuff? Great vineyards, huge barrels aging forever, poor little old monks running around testing it, just so some woman in Tulsa, Oklahoma can say it tickles her nose.”
—John Michael Hayes (b.1919)
“Now I see that going out into the testing ground of men it is the tongue and not the deed that wins the day.”
—Sophocles (497–406/5 B.C.)