| A rare genetic neuromuscular disease characterized by progressive, symmetrical, moderate to severe, distal muscle weakness and atrophy, without sensory involvement, first affecting the lower limbs (towards the end of the first decade) and then involving (within two years) the upper extremities. Patients typically develop foot drop, pes varus, hammertoes and claw hands. Pyramidal tract signs (e.g. brisk knee reflexes, positive Babinski sign, absent ankle reflexes) are initially associated but regress as disease stabilizes. |