Charcot-Marie-Tooth disease type 2B5

Charcot-Marie-Tooth disease type 2B5 (CMT2B5) is a rare inherited peripheral neuropathy belonging to the axonal (type 2) subgroup of Charcot-Marie-Tooth disease. It is caused by mutations in the NEFL gene, which encodes neurofilament light chain protein, a critical structural component of neuronal axons. This condition primarily affects the peripheral nervous system, leading to progressive degeneration of motor and sensory nerves in the extremities. Key clinical features include progressive distal muscle weakness and atrophy, predominantly affecting the lower limbs initially, with later involvement of the hands and forearms. Patients typically experience difficulty walking, foot deformities such as pes cavus (high-arched feet) and hammer toes, and reduced or absent deep tendon reflexes. Sensory loss in a stocking-glove distribution may also occur, though motor symptoms tend to predominate. Nerve conduction studies generally show reduced amplitudes consistent with axonal neuropathy, though some cases may show intermediate conduction velocities. There is currently no cure or disease-modifying treatment for CMT2B5. Management is supportive and multidisciplinary, including physical therapy to maintain muscle strength and flexibility, occupational therapy, orthotic devices such as ankle-foot orthoses to improve gait, and orthopedic surgery when needed for severe foot deformities. Pain management may be necessary for patients experiencing neuropathic pain. Regular monitoring by a neurologist is recommended to track disease progression.

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