Spinal muscular atrophy

Spinal muscular atrophy (SMA) refers to a group of diseases caused by muscle weakness and muscle atrophy due to degeneration of spinal anterior horn cells. First reported by Werdnig (1891) and Hoffmann (1893), it is also called Werdnig-Hoffmann disease. The disease can be divided into 4 types according to the age of onset and the extent of the disease: Types Ⅰ to Ⅲ are called children's SMA, which are autosomal recessive genetic diseases, and their population incidence is 1/6000 to 1/10000, which is infantile The most common fatal genetic disease. SMA onset between the ages of 20 and 30 is classified as type IV, and can show different genetic methods such as autosomal recessive, dominant, and X-linked recessive, with a population incidence of about 0.32 / 10000. Due to various clinical and genetic characteristics, it is generally believed that this disease should be separated from motor neuron diseases and become a group of independent diseases.