Also known as: Charcot-Marie-Tooth disease type 6C; CMT6C; Polyneuropathy responsive to pyridoxal 5’-phosphate


1. The Disease:

A rare axonal hereditary motor and sensory neuropathy disease characterized by progressive, peripheral, axonal sensorimotor neuropathy (of variable severity), affecting predominantly the distal lower limbs, associated with progressive, variably severe, optic atrophy, which frequently leads to visual loss.

2. The symptoms:

Lack of early signs or symptoms does not exclude the diagnosis.

Patients typically present distal limb muscle weakness and atrophy, hypo/areflexia, foot deformities, poor visual acuity (often with a central scotoma), nystagmus, and reduced peripheral and nocturnal vision.

Additional reported manifestations include sensorineural hearing loss, major joint contractures, anosmia, scoliosis/lumbar hyperlordosis, cognitive impairment and vocal cord paresis.

3. Actions to take in case of early diagnosis:

  • CMT6C is a lifelong disease requiring lifetime management and regular follow-up with a Paediatric Neurology Center Management is provided by multidisciplinary team.
  • Oral pyridoxal 5’-phosphate in the dose of 50mg/day for adult patients has improved most of the symptoms.
  • Genetic counselling should be offered to at-risk family members.

4. For more information:


iblio : Chelban V, Wilson MP, Warman Chardon J, et al. PDXK mutations cause polyneuropathy responsive to pyridoxal 5′-phosphate supplementation. Ann Neurol. 2019;86(2):225-240. PMID:31187503.