adult spinal muscular atrophy

A spinal muscular atrophy that is characterized by progressive muscular weakness and motor disability that typically presents in the third decade of life and has_material_basis_in mutations in the SMN1 or SMN2 genes that are required for the survival of motor

A spinal muscular atrophy that is characterized by progressive muscular weakness and motor disability that typically presents in the third decade of life and has_material_basis_in mutations in the SMN1 or SMN2 genes that are required for the survival of motor neurons.

Signs and symptoms

• Centrally nucleated skeletal muscle fibers
• Angulated muscle fibers
• Rimmed vacuoles
• Type 1 muscle fiber predominance
• Proximal muscle weakness
• Muscle fiber necrosis
• Increased variability in muscle fiber diameter
• Hand tremor
• Quadriceps muscle atrophy
• Tongue fasciculations

Also known as: SMA4; SPINAL MUSCULAR ATROPHY, ADULT FORM; SPINAL MUSCULAR ATROPHY, TYPE IV; spinal muscular atrophy 4