What Is Motor Neuron Disease?
8. Spinal Muscular Atrophy
Spinal muscular atrophy describes a large group of neuromuscular disorders caused by genes. There is characteristic progressive degeneration of the spinal lower motor neurons. Depending on the type, the age of onset and severity of symptoms can very. While some may be apparent at birth, there are others that do not begin until adulthood.
However, most result in worsening muscle weakness, muscle twitching, difficulty swallowing, joint contractures, and scoliosis. It occurs due to a genetic defect in the SMN1 gene, which are inherited in an autosomal recessive manner. The SMN1 gene encodes a protein that is required for the survival of motor neurons. The loss of these neurons stops the sending of signals between brain and skeletal muscles.
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