Duchene Muscular Dystrophy is an inherited neuromuscular disorder of childhood which primarily affects boys characterized by progressive muscle weakness and wasting due to a mutation in the dystrophin gene of X chromosome. Degeneration of muscles usually begins to appear in the lower half of the body then spreading into upper limbs and eventually leading to death. Between 1830 and 1850 scientists reported on an illness where boys grew gradually weaker, lost the ability to walk and died at an early age. A decade later, French neurologist Guillaume Duchene first described the DMD that now carries his name. However until 1980, only few were known regarding any form of muscular dystrophy. In 1986, MDA-supported researchers identified a specific
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Males inherit one copy of X chromosome from their mother and one copy of Y chromosome from their father while females get one copy of X chromosome from each of their parents. Therefore the probability of manifesting the disease differs between the two sexes. More specifically, each son born to a female with the DMD mutation on one of her two X chromosomes has a 50 percent chance of inheriting the defective gene and having the disease. In contrast, each daughter of a carrier female has 50 percent chance of inheriting the DMD mutation and being a carrier. Carriers usually do not have any disease symptoms because they have a second X chromosome to produce enough dystrophin protein but there is a risk of passing the mutation to their children. Although most individuals diagnosed with DMD are found to have inherited the genetic mutation from their mother, 1/3 of DMD cases has arisen spontaneously in families with no prior family history. This can possibly happen when children with DMD have a new alteration in the relevant gene called de novo mutation, a mutation in a germ cell of the mother or the fertilized egg which present in one family member for the first …show more content…
Muscle weakness begins in the pelvic and legs before affecting the arms and causes waddling gait, difficulty with running, jumping and climbing stairs. In addition children with DMD fall frequently as they are running and they use a characteristic way to get up from the floor. They first kneel putting their hands on the floor and then lift the upper body by using their hands to “climb up” their thighs in order to change from squatting to an erect position. This is a medical sign called ‘’Gowers’ maneuver’’ indicating a loss of muscle strength in lower limb muscles and can be used in diagnosis of DMD. By the age of 12, the ability to walk may be lost and children will probably need a wheelchair while also skeletal deformities such as scoliosis and lordosis start to appear. In the early teen years, progressive weakness of the cardiac and diaphragm muscles leads to the development of cardiomyopathy and respiratory disorders respectively. Males with DMD usually die at the age of 25 from respiratory infection or chronic cardiomyopathy but there are few individuals who survive beyond their
Males inherit one copy of X chromosome from their mother and one copy of Y chromosome from their father while females get one copy of X chromosome from each of their parents. Therefore the probability of manifesting the disease differs between the two sexes. More specifically, each son born to a female with the DMD mutation on one of her two X chromosomes has a 50 percent chance of inheriting the defective gene and having the disease. In contrast, each daughter of a carrier female has 50 percent chance of inheriting the DMD mutation and being a carrier. Carriers usually do not have any disease symptoms because they have a second X chromosome to produce enough dystrophin protein but there is a risk of passing the mutation to their children. Although most individuals diagnosed with DMD are found to have inherited the genetic mutation from their mother, 1/3 of DMD cases has arisen spontaneously in families with no prior family history. This can possibly happen when children with DMD have a new alteration in the relevant gene called de novo mutation, a mutation in a germ cell of the mother or the fertilized egg which present in one family member for the first …show more content…
Muscle weakness begins in the pelvic and legs before affecting the arms and causes waddling gait, difficulty with running, jumping and climbing stairs. In addition children with DMD fall frequently as they are running and they use a characteristic way to get up from the floor. They first kneel putting their hands on the floor and then lift the upper body by using their hands to “climb up” their thighs in order to change from squatting to an erect position. This is a medical sign called ‘’Gowers’ maneuver’’ indicating a loss of muscle strength in lower limb muscles and can be used in diagnosis of DMD. By the age of 12, the ability to walk may be lost and children will probably need a wheelchair while also skeletal deformities such as scoliosis and lordosis start to appear. In the early teen years, progressive weakness of the cardiac and diaphragm muscles leads to the development of cardiomyopathy and respiratory disorders respectively. Males with DMD usually die at the age of 25 from respiratory infection or chronic cardiomyopathy but there are few individuals who survive beyond their