treatment for people with this type of mutation in the united states. approximately 8% of people with dmd have a mutation that is amenable to exon 53 skipping. casimersen (amondys 45) was approved for medical use in the united states in february 2021, and it is the first fda-approved targeted treatment for people who have a confirmed mutation of the dmd gene that is amenable to exon 45 skipping. comprehensive multidisciplinary care guidelines for dmd have been developed by the us centers for disease control and prevention, and were published in 2010. an update was published in 2018. physical therapy main article: physical therapy for duchenne muscular dystrophy physical therapists are concerned with enabling patients to reach their maximum physical potential. their aim is to: minimize the development of contractures and deformity by developing a programme of stretches and exercises where appropriate anticipate and minimize other secondary complications of a physical nature by recommending bracing and durable medical equipment monitor respiratory function and advise on techniques to assist with breathing exercises and methods of clearing secretions future developments there is no cure for any of the muscular dystrophies. several drugs designed to address the root cause are under development, including gene therapy (microdystrophin), and antisense drugs (ataluren, eteplirsen etc.). other medications used include corticosteroids (deflazacort), calcium channel blockers (diltiazem) to slow skeletal and cardiac muscle degeneration, anticonvulsants to control seizures and some muscle activity, and immunosuppressants (vamorolone) to delay damage to dying muscle cells. physical therapy, braces, and corrective surgery may help with some symptoms while assisted ventilation may be required in those with weakness of breathing muscles. outcomes depend on the specific type of disorder. prognosis duchenne muscular dystrophy is a rare progressive disease which eventually affects all voluntary muscles and involves the heart and breathing muscles in later stages. life expectancy is estimated to be around 25–26, but this varies. with excellent medical care, affected men often live into their 30s. david hatch of paris, maine, may have been the oldest person in the world with the disease; he lived to at least the age of 56. the most common direct cause of death in people with dmd is respiratory failure. complications from treatment, such as mechanical ventilation and tracheotomy procedures, are also a concern. the next leading cause of death is cardiac-related conditions such as heart failure brought on by dilated cardiomyopathy. with respiratory assistance, the median survival age can reach up to 40. in rare cases, people with dmd have been seen to survive into their forties or early fifties, with proper positioning in wheelchairs and beds, and the use of ventilator support (via tracheostomy or mouthpiece), airway clearance, and heart medications. early planning of the required supports for later-life care has shown greater longevity for people with dmd. curiously, in the mdx mouse model of duchenne muscular dystrophy, the lack of dystrophin is associated with increased calcium levels and skeletal muscle myonecrosis. the intrinsic laryngeal muscles (ilms) are protected and do not undergo myonecrosis. ilms have a calcium regulation system profile suggestive of a better ability to handle calcium changes in comparison to other muscles, and this may provide a mechanistic insight for their unique pathophysiological properties. in addition, patients with duchenne muscular dystrophy also have elevated plasma lipoprotein levels, implying a primary state of dyslipidemia in patients. epidemiology dmd is the most common type of muscular dystrophy; it affects about one in 5,000 males at birth. dmd has an incidence of one in 3,600 male infants. in the us, a 2010 study showed a higher amount of those with dmd age ranging from 5 to 54 who are hispanic compared to non-hispanic whites, and non-hispanic blacks. history dr guillaume duchenne de boulogne the disease was first described by the neapolitan physician giovanni semmola in 1834 and gaetano conte in 1836. however, dmd is named after the french neurologist guillaume-benjamin-amand duchenne (1806–1875), who in the 1861 edition of his book paraplegie hypertrophique de l'enfance de cause cerebrale, described and detailed the case of a boy who had this condition. a year later, he presented photos of his patient in his album de photographies pathologiques. in 1868, he gave an account of 13 other affected children. duchenne was the first to do a biopsy to obtain tissue from a living patient for microscopic examination. notable cases alfredo ("dino", "alfredino") ferrari (born january 1932 in modena), the son of enzo ferrari, designed the 1.5 l dohc v6 engine for the model f2 at the end of 1955. but dino never saw the engine produced: he died on 30 june 1956, in modena at the age of 24, before his namesakes dino and fiat dino were made. rapper darius weems had the disease and used his notoriety to raise awareness and funds for treatment. he died at the age of 27 (his brother also had the disease, until his death at the age of 19). the film darius goes west documents weems's journey of growth and acceptance of having the disease. jonathan evison's novel, the revised fundamentals of caregiving, published in 2012, depicted a young man affected by the disease. in 2016, netflix released the fundamentals of caring, a film based on the novel. salaam venky is a 2022 indian, hindi-language film about a true story of a mother and her son, venky, who suffers from duchenne muscular dystrophy. research current research includes exon-skipping, stem cell replacement therapy, analog up-regulation, gene replacement, and supportive care to slow disease progression. efforts are ongoing to find medications that either return the ability to make dystrophin or utrophin. other efforts include trying to block the entry of calcium ions into muscle cells. exon-skipping antisense oligonucleotides (oligos), structural analogs of dna, are the basis of a potential treatment for 10% of people with dmd. the compounds allow faulty parts of the dystrophin gene to be skipped when it is transcribed to rna for protein production, permitting a still-truncated but more functional version of the protein to be produced. it is also known as nonsense suppression therapy. two kinds of antisense oligos, 2'-o-methyl phosphorothioate oligos (like drisapersen) and morpholino oligos (like eteplirsen), have tentative evidence of benefit and are being studied. eteplirsen is targeted to skip exon 51. "as an example, skipping exon 51 restores the reading frame of ~ 15% of all the boys with deletions. it has been suggested that by having 10 aons to skip 10 different exons it would be possible to deal with more than 70% of all dmd boys with deletions." this represents about 1.5% of cases. reading frame people with becker's muscular dystrophy, which is milder than dmd, have a form of dystrophin which is functional even though it is shorter than normal dystrophin. in 1990 england et al. noticed that a patient with mild becker muscular dystrophy was lacking 46% of his coding region for dystrophin. this functional, yet truncated, form of dystrophin gave rise to the notion that shorter dystrophin can still be therapeutically beneficial. concurrently, kole et al. had modified splicing by targeting pre-mrna with antisense oligonucleotides (aons). kole demonstrated success using splice-targeted aons to correct missplicing in cells removed from beta-thalassemia patients wilton's group tested exon skipping for muscular dystrophy. gene therapy researchers are working on a gene editing method to correct a mutation that leads to duchenne muscular dystrophy (dmd). researchers used a technique called crispr/cas9-mediated genome editing, which can precisely remove a mutation in the dystrophin gene in dna, allowing the body's dna repair mechanisms to replace it with a normal copy of the gene. the benefit of this over other gene therapy techniques is that it can permanently correct the "defect" in a gene rather than just transiently adding a "functional" one. genome editing through the crispr/cas9 system is not currently feasible in humans. however, it may be possible, through advancements in technology, to use this technique to develop therapies for dmd in the future. in 2007, researchers did the world's first clinical (viral-mediated) gene therapy trial for duchenne md. biostrophin is a delivery vector for gene therapy in the treatment of duchenne muscular dystrophy and becker muscular dystrophy.