Duchenne and becker muscular dystrophy
What is DMD?
Duchenne muscular dystrophy (DMD) is a genetic muscle disorder that causes weakness and wasting (atrophy) of the muscles. The first signs of DMD are often that the baby is late to sit, stand, and walk. When many children with DMD do walk it may be mainly on their toes (toe-walking) or with an odd waddle. Toddlers and children also may have large calves due to muscle damage (pseudohypertrophy). Muscle weakness usually starts in the pelvic and hip area and then moves to other muscles. Next it can affect the shoulder muscles, trunk, and arms. The disease gets worse over time (is progressive) and most people require a wheelchair by their teenage years to move around. Serious life-threatening complications may ultimately develop including disease of the heart muscle (cardiomyopathy) and breathing (respiratory) difficulties. Many of those affected do not survive past their mid-20s. Sometimes, there is mild to moderate intellectual disability and learning difficulties as well. DMD is caused by a genetic change in the DMD gene, which prevents the gene from producing dystrophin. Dystrophin is a protein that helps keep muscle cells intact and working. The disease primarily affects boys, but in rare cases it can affect girls.
SOURCE: Emory University - Department of Human Genetics in collaboration with ThinkGenetic • https://www.thinkgenetic.com/diseases/duchenne-and-becker-muscular-dystrophy/overview/7785 • DATE UPDATED: 2016-06-21
Duchenne Muscular Dystrophy. The National Organization for Rare Disorders website. http://rarediseases.org/rare-diseases/duchenne-muscular-dystrophy/
Duchenne and Becker muscular dystrophy. Genetics Home Reference website. https://ghr.nlm.nih.gov/condition/duchenne-and-becker-muscular-dystrophy
Darras BT, Miller DT, Urion DK. Dystrophinopathies. GeneReviews website. http://www.ncbi.nlm.nih.gov/books/NBK1119/