Spinal Muscular Atrophy

From WackyWiki

Spinal Muscular Atrophy (SMA) is a neuromuscular disease characterized by progressive degeneration of the motor cells of the spinal cord, resulting in progressive muscular atrophy (wasting away) and weakness. This is the result of denervation, or loss of the signal to contract, that is transmitted from the spinal cord. This is normally transmitted from motor neurons in the spinal cord to muscle via the motor neuron's axon, but either the motor neuron with its axon, or the axon itself, is lost in all forms of SMA.

The features of SMA are strongly related to its severity and age of onset. SMA caused by mutation of the SMN gene has a wide range, from infancy to adult, fatal to trivial, with different affected individuals manifesting every shade of impairment between these two extremes. Many of the symptoms of SMA relate to secondary complications of muscle weakness, and as such can be at least partially remediated by prospective therapy.