Muscular dystrophy is a group of genetic diseases where the skeletal muscles weaken and break down over time. These muscles are important for movement, so this is often impaired in patients. It also has a direct correlation to a disease of the heart known as cardiomypathy. The most common forms of the disorder are Duchenne muscular dystrophy and Becker muscular dystrophy.
The mutation which causes this disease occurs on the gene DMD, which codes for the protein dystrophin.
The disease was discovered when a neurologist from France named Guilaumme Duchenne (likely where the name of the disease came from) wrote about the disease in the 1860’s.
The incidence rate of the disease in the United States is about 1 in every 6,667 boys and men between the ages of 5 and 24. Worldwide, 1 in between 3,500 and 5,000 newborn male babies have muscular dystrophy. Out of these people, those of Hispanic or white race were generally more affected, while those of African American lineage weren't as affected by the disease.
Symptoms include: Skills such as walking or standing do not come easily, wheelchair-bound by teenage years, heart muscle grows and irregular heartbeat, immense fatigue, legs/feet swell, often short of breath, endocrine system might function improperly, causes learning disabilities and brain function
Muscular dystrophy is treated through a variety of methods, such as physical and occupational therapies, splints and braces, aids to make movement and walking possible, corticosteroid medications, and antispasmodic treatments to help muscle spasms.
Muscular dystrophy is far more likely to occur in males then females, because the mutation occurs on the sex chromosome X. Since men only have one of the chromosome, the gene only needs to mutate on one chromosome. But in females, the mutation needs to occur on both X chromosomes. This disease is inherited and is a recessive trait, making it quite rare.
The prognosis for someone with muscular dystrophy is anywhere between 20-40 years. With treatment, however, a patient's life expectancy could move into later adulthood.
Diagnosing a patient with muscular dystrophy is a multi-step process, where many forms of testing have to be done. Some of these tests are muscle biopsies and genetic testing for the mutation of the gene. Blood tests are done for an enzyme called serum creatine kinase, which is release when muscles break down. Imaging with MRIs and ultrasounds to look at the quality of the muscle is also done.
Recently, the National Human Genome Research Institute founded the Center for Mendelian Genomics, which includes muscular dystrophy (a Mendelian disease). Their job is to investigate the genes that codes for particular proteins as a cause of disease. As of 2016, they are planning on providing $40 million in funding for the center.
Other up and coming research includes work done by the Muscular Dystrophy Association. Current trials are being undergone for different forms of cures, including exon skipping and gene therapy. As of Sept. 2016, eteplirsen became the first drug approved by the FDA to help muscular dystrophy (disease-modifying drug).