EFO_0010567 (spastic tetraplegia and axial hypotonia, progressive) is an autosomal recessive, neurologic disorder characterized by loss of motor abilities in the first year of life, after which severe, progressive spastic tetraparesis develops. Affected individuals have severe axial hypotonia, hyperekplexia, hypertonia, and myokymia, reflecting upper motor neuron involvement. Cognitive development may be affected. Also known as: SOD1 deficiency, autosomal recessive.