Duchene Muscular Dystrophy

Is a genetic disease, inherited in most cases. Apart from rare exceptions, only males are affected in Duchenne myopathy. The mothers are carriers of an anomaly of one chromosome X. They can transmit genetic abnormalities to their children: if you have a child, this is theoretically a possibility of having two sick. If a girl is one chance in 2 of being a carrier. Children with Duchenne muscular dystrophy have an almost total lack of dystrophin, a protein essential for muscle that is supposedly responsible for maintenance of the structure of muscle cells. It can prevent the onset of the disease when it occurs in a family where there are known cases of this disease, using genetic counseling and prenatal diagnosis. In other cases can not be avoided. Table clínicoLa DMD affects 1 in 3000 to 4000 newborns. It manifests clinically between 2 and 6 years with the gastrocnemius muscle Pseudohypertrophy, weakness of lower limbs and pelvic girdle muscles, progressing to the shoulder girdle and upper limbs are muscular alterations simétricas.Las first signs can include difficulty climbing stairs or rising from the ground.

Patients are confined to a wheelchair at the age of 15 years and who die around age 20 from respiratory infections or heart failure. DMD is a disease of skeletal muscle fibers pathophysiological changes involving the heart, diaphragm and nervous system. It is therefore necessary to study abnormalities of the dystrophin-glycoprotein complex heart and brain.

GabineteLos laboratory data and serum CPK creatine values ​​are very high in those affected in the preclinical stage, as the disease progresses downward trend. It is noted that bilipídicas layers protect the release of CPK from the protoplasm in the normal muscle, so that due to the absence of dystrophin in DMD muscle during contraction, damage occurs in the lipid layer. The EMG shows decrease in average duration of motor unit potentials and increased polyphasic forms that reflect muscle fiber loss.

MolecularesEl aspects isolation of the gene has been localized to Xp21. Contains more than 2 million nucleotides and 79 exons. Most of the mutations of DMD / BMD are intragenic deletions: 30% are located in the proximal 5 'exons 2 to 20 and 70% in the distal region of exons 44 to 53. This area suggests that some features of DND predispose to breaks or recombination. In 5% of cases there is duplication and 30% did not detect deletions or duplications and it is unknown molecular sion. Normally, dystrophin is expressed in skeletal muscle, cardiac muscle, visceral and vascular smooth in the brain, nervous system, neurons are those that fundamentally express. The severe phenotype of DMD caused by deletion or duplication results in a truncated or nonfunctional. We have described two possible models for DMD pathogenic, the first suggests that the complex forms a structural bridge between the external basal lamina and the internal cytoskeleton and dystrophin in the absence of a defect in the membrane that causes the muscle be susceptible to breakage during contractile activity plasmalemales, another model points to as an organizer of the dystrophin membrane cytoskeleton, and this in its aggregation function of ion channels and neurotransmitter receptors.

Within the study of muscle fibers, as well as muscle biopsy, there is immunohistochemistry. In this process, antibodies are used antidistrofina or against any of the components of the complex called DGC (dystrophin-glycoprotein complex), evaluating both the amount and quality of dystrophin and / or glycoproteins associated with it. The complete absence of dystrophin or figures of less than 3% are specific characteristics of the severe phenotype of Duchenne muscular dystrophy. The treatment, currently only consists of support measures: physical, psychomotor, occupational therapy and control of the treatments being tested complicaciones.Se who try to cure muscular dystrophy. Although they are still experimental treatments, preliminary data indicate that in the future could be possible to cure this disease. ReferenciasDistrofia_muscular_de_Duchenne Retrieved April 29 Favaloro muscular dystrophy 2009Fundación Available at: http://www.fundacionfavaloro.org/educa _IN_distrofia_muscular.pdf Retrieved April 29 2009Guizar-Vazquez, Jesus. Clinical genetics. Editorial Manual Moderno. Mexico City, 2005