Genetic Disorders: Muscular Dystrophy
Muscular dystrophy is a group of diseases that cause progressive weakness and loss of muscle mass. 349 out of 2.37 million males aged 5-24 were reported to have DMD or BMD in the United States. This means that about 15 of every 100,000 males aged between 5-24 were affected that year. Also, a close friend of mine had muscular dystrophy so it played a role in my life. I wanted to know if it could be cured and if not was there any treatments for it. Muscular dystrophy could potentially be cured through gene therapy, but currently the disease is best treated with a steroid named Prednisone.
Muscular dystrophy is a genetic disorder. It is inherited just like height and eye color. Scientists now know that a defective gene causes each type of muscular dystrophy. In …show more content…
some cases, if either parent carries a gene for muscular dystrophy, their child may develop it. Their child could also become a carrier. With some types of muscular dystrophy, however, both parents must pass along the defective gene.
Muscular dystrophy (MD) is a group of nine neuromuscular diseases. This means it is related both to the nervous system and to the muscles. About 250,000 people in the United States have muscular dystrophy. Muscular dystrophy (MD) is a group of nine neuromuscular diseases. This means it is related both to the nervous system and to the muscles. About 250,000 people in the United States have muscular dystrophy. There are many different types of Muscular Dystrophy but how do they affect your body? Myotonic (also called MMD or Steinert's disease). The most common form of muscular dystrophy in adults, myotonic muscular dystrophy affects both men and women, and it usually appears any time from early childhood to adulthood. In rare cases, it appears in newborns (congenital MMD). The name refers to a symptom, myotonia -- prolonged spasm or stiffening of muscles after use. This symptom is usually worse in cold temperatures. The disease causes muscle weakness and also affects the central nervous system, heart, gastrointestinal tract, eyes, and hormone-producing glands. In most cases, daily living isn't restricted for many
years. Those with myotonic MD have a decreased life expectancy. Duchenne is the most common form of muscular dystrophy in children. Duchenne muscular dystrophy affects only males. It appears between the ages of 2 and 6. The muscles decrease in size and grow weaker over time yet may appear larger. Disease progression varies, but many people with Duchenne (1 in 3,500 boys) need a wheelchair by the age of 12. In most cases, the arms, legs, and spine become progressively deformed, and there may be some cognitive impairment. Severe breathing and heart problems mark the later stages of the disease. Those with Duchenne MD usually die in their late teens or early 20s. Becker, this form is similar to Duchenne muscular dystrophy, but the disease is much milder: symptoms appear later and progress more slowly. It usually appears between the ages of 2 and 16 but can appear as late as age 25. Like Duchenne muscular dystrophy, Becker muscular dystrophy affects only males (1 in 30,000) and causes heart problems. Disease severity varies. Those with Becker can usually walk into their 30s and live further into adulthood. Limb-girdle, this appears in the teens to early adulthood and affects males and females. In its most common form, Limb-girdle muscular dystrophy causes progressive weakness that begins in the hips and moves to the shoulders, arms, and legs. Within 20 years, walking becomes difficult or impossible. Sufferers typically live to middle age to late adulthood. Facioscapulohumeral refers to the muscles that move the face, shoulder blade, and upper arm bone. This form of muscular dystrophy appears in the teens to early adulthood and affects males and females. It progresses slowly, with short periods of rapid muscle deterioration and weakness. Severity ranges from very mild to completely disabling. Walking, chewing, swallowing, and speaking problems can occur. About 50% of those with facioscapulohumeral MD can walk throughout their lives, and most live a normal life span. Congenital means present at birth. Congenital muscular dystrophies progress slowly and affect males and females. The two forms that have been identified -- Fukuyama and congenital muscular dystrophy with myosin deficiency -- cause muscle weakness at birth or in the first few months of life, along with severe and early contractures (shortening or shrinking of muscles that causes joint problems). Fukuyama congenital muscular dystrophy causes abnormalities in the brain and often seizures. Oculopharyngeal means eye and throat. This form of muscular dystrophy appears in men and women in their 40s, 50s, and 60s. It progresses slowly, causing weakness in the eye and face muscles, which may lead to difficulty swallowing. Weakness in pelvic and shoulder muscles may occur later. Choking and recurrent pneumonia may occur. Distal this group of rare diseases affects adult men and women. It causes weakness and wasting of the distal muscles (those farthest from the center) of the forearms, hands, lower legs, and feet. It is generally less severe, progresses more slowly, and affects fewer muscles than other forms of muscular dystrophy. Emery-Dreifuss this rare form of muscular dystrophy appears from childhood to the early teens and affects only males. It causes muscle weakness and wasting in the shoulders, upper arms, and lower legs. Life-threatening heart problems are common and can also affect carriers -- those who have the genetic information for the disease but do not develop the full-blown version (including mothers and sisters of those with Emery-Dreifuss MD). Muscle shortening (contractures) occurs early in the disease. Weakness can spread to chest and pelvic muscles. The disease progresses slowly and causes less severe muscle weakness than some other forms of muscular dystrophy.
At the age of 24, Benjamin Dupree has outlived many people with Duchenne muscular dystrophy. The problem is that Dupree's body doesn't make dystrophin, a protein in muscle fibers that acts like a shock absorber. Without it, your biceps, calf muscles, and diaphragm slowly turn to a fatlike substance. You end up on a ventilator, and then your heart stops. Dystrophin is manufactured by a gene that is not only the largest in the human genome but the largest anywhere in nature. It consists of 79 components known as exons, each an instruction for one ingredient of the protein. A year ago, in December, he learned how a technology called CRISPR might make that possible. A scientist named Eric Olson had requested some of Dupree's blood a few months earlier, and Dupree had agreed. A biologist at the University of Texas Southwestern Medical Center, could show him the results--and what some scientists now predict is the likeliest way to cure Duchenne. Using CRISPR, which makes it possible to snip DNA open at a precisely chosen spot, a team at the hospital had modified his cells in a dish, cutting through the extra exon. When DNA is broken this way, a cell races to make a repair, but the natural repair process typically makes a small error. This causes the unwanted genetic instructions to become unintelligible. The editing process required only a single step and had taken three days. In an image taken with a microscope, his cells were clouded with green puffs of perfect dystrophin.
A powerful steroid, prednisone, was recently found that it helped reduce the effects of Duchenne’s muscular dystrophy. Prednisone is not a cure but just a treatment. One out of every 3,500 male infants in the United States has inherited a defective gene that causes Duchenne's muscular dystrophy. At about age 3, afflicted children develop a swaying or waddling motion when they walk. From that seemingly innocent early stage, the disease advances until weakened muscles can no longer hold the body upright. Fenichel and his colleagues have now confirmed that early promise in a multicenter trial of 89 Duchenne's patients ranging from 7 to 14 years of age. In a year-long experiment, Fenichel's team found that a daily dose of 0.75 milligrams of prednisone per kilogram of body weight seemed to offer the best short at fighting the muscle-sapping disorder. After that initial phase, they continued to treat the boys but had to lower the maximum dose for some patients because of harsh side effects. Three years later, the 49 boys taking the highest daily doses (at least 0.65 mg/kg) showed the most favorable response, Fenichel reports. Their muscle strength (measured by weight-lifting tests) declined by an average of 0.017 unit per year, whereas the boys on lower doses lost about 0.164 unit per year. Altough the study did not include a control group, Fenichel says participants showed a clear benefit compared with Duchenne's patients in general, who typically lose about 0.4 unit per year. Some volunteers actually gained muscle strength, he adds -- an improvement readily noted by their parents.
Muscular dystrophy is a genetic disorder. It is inherited just like height and eye color. Scientists now know that a defective gene causes each type of muscular dystrophy. In …show more content…
some cases, if either parent carries a gene for muscular dystrophy, their child may develop it. Their child could also become a carrier. With some types of muscular dystrophy, however, both parents must pass along the defective gene.
Muscular dystrophy (MD) is a group of nine neuromuscular diseases. This means it is related both to the nervous system and to the muscles. About 250,000 people in the United States have muscular dystrophy. Muscular dystrophy (MD) is a group of nine neuromuscular diseases. This means it is related both to the nervous system and to the muscles. About 250,000 people in the United States have muscular dystrophy. There are many different types of Muscular Dystrophy but how do they affect your body? Myotonic (also called MMD or Steinert's disease). The most common form of muscular dystrophy in adults, myotonic muscular dystrophy affects both men and women, and it usually appears any time from early childhood to adulthood. In rare cases, it appears in newborns (congenital MMD). The name refers to a symptom, myotonia -- prolonged spasm or stiffening of muscles after use. This symptom is usually worse in cold temperatures. The disease causes muscle weakness and also affects the central nervous system, heart, gastrointestinal tract, eyes, and hormone-producing glands. In most cases, daily living isn't restricted for many
years. Those with myotonic MD have a decreased life expectancy. Duchenne is the most common form of muscular dystrophy in children. Duchenne muscular dystrophy affects only males. It appears between the ages of 2 and 6. The muscles decrease in size and grow weaker over time yet may appear larger. Disease progression varies, but many people with Duchenne (1 in 3,500 boys) need a wheelchair by the age of 12. In most cases, the arms, legs, and spine become progressively deformed, and there may be some cognitive impairment. Severe breathing and heart problems mark the later stages of the disease. Those with Duchenne MD usually die in their late teens or early 20s. Becker, this form is similar to Duchenne muscular dystrophy, but the disease is much milder: symptoms appear later and progress more slowly. It usually appears between the ages of 2 and 16 but can appear as late as age 25. Like Duchenne muscular dystrophy, Becker muscular dystrophy affects only males (1 in 30,000) and causes heart problems. Disease severity varies. Those with Becker can usually walk into their 30s and live further into adulthood. Limb-girdle, this appears in the teens to early adulthood and affects males and females. In its most common form, Limb-girdle muscular dystrophy causes progressive weakness that begins in the hips and moves to the shoulders, arms, and legs. Within 20 years, walking becomes difficult or impossible. Sufferers typically live to middle age to late adulthood. Facioscapulohumeral refers to the muscles that move the face, shoulder blade, and upper arm bone. This form of muscular dystrophy appears in the teens to early adulthood and affects males and females. It progresses slowly, with short periods of rapid muscle deterioration and weakness. Severity ranges from very mild to completely disabling. Walking, chewing, swallowing, and speaking problems can occur. About 50% of those with facioscapulohumeral MD can walk throughout their lives, and most live a normal life span. Congenital means present at birth. Congenital muscular dystrophies progress slowly and affect males and females. The two forms that have been identified -- Fukuyama and congenital muscular dystrophy with myosin deficiency -- cause muscle weakness at birth or in the first few months of life, along with severe and early contractures (shortening or shrinking of muscles that causes joint problems). Fukuyama congenital muscular dystrophy causes abnormalities in the brain and often seizures. Oculopharyngeal means eye and throat. This form of muscular dystrophy appears in men and women in their 40s, 50s, and 60s. It progresses slowly, causing weakness in the eye and face muscles, which may lead to difficulty swallowing. Weakness in pelvic and shoulder muscles may occur later. Choking and recurrent pneumonia may occur. Distal this group of rare diseases affects adult men and women. It causes weakness and wasting of the distal muscles (those farthest from the center) of the forearms, hands, lower legs, and feet. It is generally less severe, progresses more slowly, and affects fewer muscles than other forms of muscular dystrophy. Emery-Dreifuss this rare form of muscular dystrophy appears from childhood to the early teens and affects only males. It causes muscle weakness and wasting in the shoulders, upper arms, and lower legs. Life-threatening heart problems are common and can also affect carriers -- those who have the genetic information for the disease but do not develop the full-blown version (including mothers and sisters of those with Emery-Dreifuss MD). Muscle shortening (contractures) occurs early in the disease. Weakness can spread to chest and pelvic muscles. The disease progresses slowly and causes less severe muscle weakness than some other forms of muscular dystrophy.
At the age of 24, Benjamin Dupree has outlived many people with Duchenne muscular dystrophy. The problem is that Dupree's body doesn't make dystrophin, a protein in muscle fibers that acts like a shock absorber. Without it, your biceps, calf muscles, and diaphragm slowly turn to a fatlike substance. You end up on a ventilator, and then your heart stops. Dystrophin is manufactured by a gene that is not only the largest in the human genome but the largest anywhere in nature. It consists of 79 components known as exons, each an instruction for one ingredient of the protein. A year ago, in December, he learned how a technology called CRISPR might make that possible. A scientist named Eric Olson had requested some of Dupree's blood a few months earlier, and Dupree had agreed. A biologist at the University of Texas Southwestern Medical Center, could show him the results--and what some scientists now predict is the likeliest way to cure Duchenne. Using CRISPR, which makes it possible to snip DNA open at a precisely chosen spot, a team at the hospital had modified his cells in a dish, cutting through the extra exon. When DNA is broken this way, a cell races to make a repair, but the natural repair process typically makes a small error. This causes the unwanted genetic instructions to become unintelligible. The editing process required only a single step and had taken three days. In an image taken with a microscope, his cells were clouded with green puffs of perfect dystrophin.
A powerful steroid, prednisone, was recently found that it helped reduce the effects of Duchenne’s muscular dystrophy. Prednisone is not a cure but just a treatment. One out of every 3,500 male infants in the United States has inherited a defective gene that causes Duchenne's muscular dystrophy. At about age 3, afflicted children develop a swaying or waddling motion when they walk. From that seemingly innocent early stage, the disease advances until weakened muscles can no longer hold the body upright. Fenichel and his colleagues have now confirmed that early promise in a multicenter trial of 89 Duchenne's patients ranging from 7 to 14 years of age. In a year-long experiment, Fenichel's team found that a daily dose of 0.75 milligrams of prednisone per kilogram of body weight seemed to offer the best short at fighting the muscle-sapping disorder. After that initial phase, they continued to treat the boys but had to lower the maximum dose for some patients because of harsh side effects. Three years later, the 49 boys taking the highest daily doses (at least 0.65 mg/kg) showed the most favorable response, Fenichel reports. Their muscle strength (measured by weight-lifting tests) declined by an average of 0.017 unit per year, whereas the boys on lower doses lost about 0.164 unit per year. Altough the study did not include a control group, Fenichel says participants showed a clear benefit compared with Duchenne's patients in general, who typically lose about 0.4 unit per year. Some volunteers actually gained muscle strength, he adds -- an improvement readily noted by their parents.