In Duchennes muscular dystrophy, calf muscle is: September 2009

Ans. D: Pseudohyperophied Duchenne muscular dystrophy is by far the most common childhood-onset muscular dystrophy, afflicting 1 in 3300 boys with an overall prevalence of 63 cases per million. One third of these cases are due to spontaneous mutations, while the rest are inherited in an X-linked dominant manner. Duchenne muscular dystrophy clinically manifests in patients aged 3-7 years, with development of lordosis, a waddling gait, and the Cowers sign. Calf pseudohyperophy follows 1-2 years later. Most patients are wheelchair bound by age 12 years. Diagnostic criteria include: Weakness with onset in the legs; Hyperlordosis with wide-based gait; Hyperophy of weak muscles; Progressive course over time; Reduced muscle contractility on electrical stimulation in advanced stages of the disease; and (6) absence of bladder or bowel dysfunction, sensory disturbance, or febrile illness. Duchenne muscular dystrophy is much more than a disease of skeletal muscles. Dystrophin is also found in the hea, brain, and smooth muscle. Late-stage cardiac fibrosis can lead to output failure and pulmonary congestion, a common cause of death. Additionally, cardiac fibrosis can include cardiomyopathy and conduction abnormalities, which can induce fatal arrhythmias.