Charcot-Marie-Tooth disease type 4B3
Findings
No curated finding names Charcot-Marie-Tooth disease type 4B3 yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
Charcot-Marie-Tooth disease type 4B3 (CMT4B3) is a subtype of Charcot-Marie-Tooth type 4 characterized by a childhood onset of slowly progressing, demyelinating sensorimotor neuropathy, focally folded myelin sheaths in nerve biopsy, reduced nerve conduction velocities (less than 38 m/s), and the typical CMT phenotype (i.e. distal muscle weakness and atrophy, and sensory loss).
Definition from the Mondo Disease Ontology (MONDO:0014117), read 2026-09-29. CC BY 4.0.
- Inheritance
- Autosomal recessive inheritance
- Onset and course
- Juvenile onset
HPO, annotations 2026-09-02
Features
12 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.
- AreflexiaHPOHP:0001284
- 3 of 3 reported patients
- Decreased nerve conduction velocityHPOHP:0000762
- 3 of 3 reported patients
- Distal lower limb muscle weaknessHPOHP:0009053
- 3 of 3 reported patients · Juvenile onset
- Distal sensory impairmentHPOHP:0002936
- 3 of 3 reported patients
- Lower limb muscle weaknessHPOHP:0007340
- 3 of 3 reported patients
- Muscle fibrillationHPO
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.
- SBF1HGNC:10542
- Strong · Labcorp Genetics (formerly Invitae) · Autosomal recessive · 2021
- Strong · PanelApp Australia · Autosomal recessive · 2025
- Moderate · ClinGen · Autosomal recessive · 2026
- Supportive · Orphanet · Autosomal recessive · 2021
- Limited · Ambry Genetics · Autosomal recessive · 2020
Where it sits
- A kind of
Other names
4 names
Resolves to: Charcot-Marie-Tooth disease type 4B3
- Also called
- Charcot-Marie-Tooth disease type 4 caused by mutation in SBF1Charcot-Marie-Tooth disease with focally folded myelinCMT4B3SBF1 Charcot-Marie-Tooth disease type 4