Where is dystrophin normally found

The dystrophin complex acts as an anchor, connecting each muscle cell's structural framework cytoskeleton with the lattice of proteins and other molecules outside the cell extracellular matrix. The dystrophin complex may also play a role in cell signaling by interacting with proteins that send and receive chemical signals.

Little is known about the function of dystrophin in nerve cells. Research suggests that the protein is important for the normal structure and function of synapses, which are specialized connections between nerve cells where cell-to-cell communication occurs. More than 2, mutations in the DMD gene have been identified in people with the Duchenne and Becker forms of muscular dystrophy.

These conditions occur almost exclusively in males and are characterized by progressive muscle weakness and wasting atrophy and a heart condition called dilated cardiomyopathy. Most of the mutations that cause these conditions delete part of the DMD gene. Other mutations abnormally duplicate part of the gene or change a small number of DNA building blocks nucleotides in the gene. Mutations that cause Becker muscular dystrophy, which typically has milder features and appears at a later age than Duchenne muscular dystrophy, usually lead to an abnormal version of dystrophin that retains some function.

Mutations that cause the more severe Duchenne muscular dystrophy typically prevent any functional dystrophin from being produced.

Skeletal and cardiac muscle cells without enough functional dystrophin become damaged as the muscles repeatedly contract and relax with use. The damaged cells weaken and die over time, causing the characteristic muscle weakness and heart problems seen in Duchenne and Becker muscular dystrophy.

More than 30 mutations in the DMD gene can cause an X-linked form of familial dilated cardiomyopathy. DMD was first described by the French neurologist Guillaume Benjamin Amand Duchenne in the s, but until the s, little was known about the cause of any kind of muscular dystrophy. In , the protein associated with this gene was identified and named dystrophin. Lack of the dystrophin protein in muscle cells causes them to be fragile and easily damaged.

DMD has an X-linked recessive inheritance pattern and is passed on by the mother, who is referred to as a carrier. DMD carriers are females who have a normal dystrophin gene on one X chromosome and an abnormal dystrophin gene on the other X chromosome. Most carriers of DMD do not themselves have signs and symptoms of the disease, but a minority do.

Symptoms can range from mild skeletal muscle weakness or cardiac involvement to severe weakness or cardiac effects and can begin in childhood or adulthood. Until relatively recently, boys with DMD usually did not survive much beyond their teen years.

Thanks to advances in cardiac and respiratory care, life expectancy is increasing and many young adults with DMD attend college, have careers, get married, and have children. Survival into the early 30s is becoming more common than before. MDA-supported researchers are actively pursuing several exciting strategies in DMD, such as gene therapy , exon skipping , stop codon read-through and gene repair. Gov't Research Support, U. Gov't, P. Researchers have developed various tests that can be used to identify, locate, and measure dystrophin.

These tests on muscle tissue include: Western blot shows if there is dystrophin, and how much Immunohistochemistry, often shortened to IHC shows if there is dystrophin, and where it is located. Learn More. Learn more about the science of Duchenne. Take a closer look at diagnostic tests. The typical progression of Duchenne.