August is Spinal Muscular Atrophy (SMA) Awareness month. SMA is a group of genetic disorders that are characterized by a loss of certain protein that is necessary for the survival of some motor neurons in the spinal cord. The loss of these neurons leads to progressive muscle weakness and muscle atrophy, starting starting with the... Read more »
SMA linked to chromosome 5. Spinal muscular atrophy types 1 through 4 all result from a single known cause — a deficiency of a protein called SMN, for "survival of motor neuron." Deficiency of SMN protein occurs when a mutation (flaw) is present in both copies of the SMN1 gene — one on each chromosome 5.