(b) : Muscular dystrophy is characterised by progressive skeletal muscle weakness, defects in muscle proteins and the death of muscle cells and tissue. Myasthenia gravis is an auto-immune neuromuscular disease in which muscle becomes weak, which is caused by circulating antibodies that block acetylcholine receptors at the postsynaptic neuromuscular junction inhibiting the excitatory effects of the acetylcholine. Gout is inflammation of joints which is caused by elevated levels of uric acid in the blood which crystallises and the crystals are deposited in joints, tendons and surrounding tissues.