Charcot-Marie-Tooth disease type 4B2 (CMT4B2) is a subtype of Charcot-Marie-Tooth type 4 characterized by a severe, early childhood-onset of demyelinating sensorimotor neuropathy, early-onset glaucoma, focally folded myelin sheaths in the peripheral nerves, severely reduced nerve conduction velocities, and the typical CMT phenotype (i.e. distal muscle weakness and atrophy, sensory loss, and frequent pes cavus). Severe visual impairment leading to visual loss has also been reported. The disease is Charcot-Marie-Tooth disease type 4B2 (MONDO_0011475). Also known as: CMT4B2, Charcot-Marie-Tooth disease type 4 caused by mutation in SBF2, Charcot-Marie-Tooth neuropathy type 4B2, SBF2 Charcot-Marie-Tooth disease type 4, autosomal recessive Charcot-Marie-Tooth disease with focally folded myelin sheaths type 4B2.