[Proximal spinal muscular atrophy in the adult]

Based on personal experience and recent advances in the molecular genetics of spinal muscular atrophies (SMA), the author reviews the main features of adult SMA predominantly affecting the proximal musculature. Hereditary SMA forms linked to characteristic chromosome abnormalities are distinguished from those that have not been linked to any known gene. Among the first type, recessive autosomal inherited forms linked to chromosome 5 are mentioned and the description is extended to progressive bulbar-spinal amyotrophy and Kennedy syndrome, linked to the X chromosome, whose gene also codifies androgenic receptors, constituting a syndrome with clear neuro-endocrine involvement. In dealing with SMA forms that have not been linked to a gene, the author details, always from personal experience, those with scapuloperoneal involvement, of which Stark-Kaeser syndrome is the prototype. Finally, the author discusses non hereditary types, covering current knowledge of chronic anterior poliomyelitis, the concept of monomelic spinal muscular atrophy and post-poliomyelitis muscle syndrome. The author's extensive personal bibliography completes the chapter.