Charcot-Marie-Tooth disease type 4B2
Findings
No curated finding names Charcot-Marie-Tooth disease type 4B2 yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
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.
Definition from the Mondo Disease Ontology (MONDO:0011475), read 2026-09-29. CC BY 4.0.
- Inheritance
- Autosomal recessive inheritance
- Onset and course
- Childhood onset
HPO, annotations 2026-09-02
Features
44 features
What the disease is reported to present with, and how often among people who have it — never how often a feature means the disease. HPO, annotations 2026-09-02.
- Distal muscle weaknessHPOHP:0002460
- 4 of 4 reported patients
- Abnormal foot morphologyHPOHP:0001760
- Very frequent (80% to 99% of cases)
- Areflexia of lower limbsHPOHP:0002522
- Very frequent (80% to 99% of cases)
- Decreased distal sensory nerve action potentialHPOHP:0007230
- Very frequent (80% to 99% of cases)
- Distal lower limb muscle weaknessHPOHP:0009053
- Very frequent (80% to 99% of cases)
Genes
1 gene
Germline variants in the gene encoding each protein, as classified by GenCC submitters, each in their own words. Limited, disputed and refuted submissions are listed too.
- SBF2HGNC:2135
- Definitive · ClinGen · Autosomal recessive · 2021
- Definitive · G2P · Autosomal recessive · 2017
- Strong · Ambry Genetics · Autosomal recessive · 2018
- Strong · Labcorp Genetics (formerly Invitae) · Autosomal recessive · 2018
- Strong · PanelApp Australia · Autosomal recessive · 2025
- Supportive · Orphanet · Autosomal recessive · 2021
Where it sits
- A kind of
Other names
3 names
Resolves to: Charcot-Marie-Tooth disease type 4B2
- Also called
- Charcot-Marie-Tooth disease type 4 caused by mutation in SBF2CMT4B2SBF2 Charcot-Marie-Tooth disease type 4