<prompt> Duchenne Muscular Dystrophy is a disease of:Neuromuscular junctionSarcolemmal proteinsMuscle contractile proteinsDisuse atrophy due to muscle weakness  <response>: Answer is B Sarcolemmal protein : Duchenne muscular dystrophy is caused kr a mutation in the gene responsible few producing dystrophin. Dystrophin is subsarcolemmal protein Nelson localized to the inner surface of the sarcolemma of the muscle fibre. Harrison 17th2683 Dystrophin is pa of Dystrophin - Glycoprotein sarcolemmal complex and this protein deficiency leads to secondary loss of sarcoglycans and dystroglycans resulting in weakness of sarcolemma, causing membrane tears and muscle fibre necrosis Duchenne muscular dystrophy: Review pseudohyperophic muscular dystrophy Duchenne muscular dystrophy is the most common hereditary neuromuscular disease affecting all races and ethnic groups. Inheritance : X linked recessive Presentation occurs between ages 3 and 5 Clinical manifestations: Gowers sign is positivedeg Pseudohyperophy of calf is seendeg muscle is replaced by fat connective tissue Loss of muscle strength is progressive. 2 Proximal muscles and neck flexors are involved more. 2 Leg involvement is more severe than arm involvement. Contractures of heel cords and iliotibial band occurs by age of 6 years Progressive scoliosis develops. Complications: Chest deformityQ scoliosis : Impairs pulmonary functiondeg By age of 16 and 18 years patients are predisposed to serious pulmonary fatal infections. Cardiac: Cardiomyopathy and CHF may be seen Cardiac cause of death is uncommon Intellectual impairment : is commondeg IQ is one SD below the mean Remember: Onset 2 Before age of 5 2 Confined to wheel chair Inability to walk After age of 12 e Respiratory failure In second or third decade after 16-18 years2 Laboratory diagnosis: Serum creatinephosphokinase CKQ : elevated 20-.100 times EMG : features of myopathy Muscle biopsyQ : - Definitive diagnosis established on basis of dystrophin deficiency in biopsied muscle tissue - Groups of necrotic and regenerating muscle fibres are seen. Treatment: - Glucocoicoids Prednisolone have been tried. - Significant alteration in the progression of disease has been seen with prednisolone. 