[Clinical picture, pathogenesis and geneology of hereditary progressive spinal muscular atrophies].

A clinical-genealogical and electromyographic investigation of 142 patients with spinal muscular atrophies demonstrated a heterogeneous nature of spinal amyotrophies. A group of amyotrophies was specified as determined by the degeneration of only motor cells of the anterior corns. This group includes Werdnig-Hoffmann's infantile spinal amyotrophy, late childhood spinal amyotrophy, Kugelberg-Welander's juvenile amyotrophy, and late distal spinal amyotrophy. The group of spinal neural amyotrophies is made up of the clinical variants which are characterized by the parallel involvement of spinal motor cells and their axons. Spinal neural amyotrophies include the autosomal-recessive childhood and the autosomal-dominant juvenile variants.