A new genetic test targeting the most common types of muscular dystrophy--those caused by mutations in the dystrophin gene--is far quicker with greater accuracy and sensitivity than existing tests. It can be used to confirm clinical diagnoses, to test female family members who may be carriers, and to perform prenatal testing.
The test was developed by Michael Zwick, PhD, and Madhuri Hegde, PhD, assistant professors in the Department of Human Genetics and the Emory Genetics Laboratory in the Emory University School of Medicine.
Muscular dystrophy includes more than 30 genetic diseases characterized by progressive weakness and degeneration of the skeletal muscles that control movement. Some forms are seen in infancy or childhood, while others may not appear until middle age or later. Duchenne muscular dystrophy (DMD) is the most common form of muscular dystrophy and primarily affects boys. It is caused by absence of dystrophin, an important muscle protein involved in maintaining the strength of muscle fibers.
According to the National Institute of Neurodegenerative Diseases and Stroke (NINDS), DMD onset is between 3 and 5 years, with rapid progression. Most boys are unable to walk by age 12 and later need a respirator to breathe. Girls in these families have a 50 percent chance of inheriting and passing the defective gene to their children. Becker muscular dystrophy, which is similar to Duchenne but less severe, results from faulty or not enough dystrophin.
As currently implemented the new test, called EmArray Dystrophin, detects 99 percent of mutations in the dystrophin gene including deletions, duplications and point mutations.
The EmArray Dystrophin test uses a new kind of microarray technology that contains the entire sequence of the dystrophin gene, the largest known gene in humans, on a chip the size of a microscope slide. The test initially detects deletions and duplications, then microarray-based resequenc
Contact: Holly Korschun