Charcot-Marie-Tooth disease, demyelinating, type 1G
Findings
No curated finding names Charcot-Marie-Tooth disease, demyelinating, type 1G yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
A rare autosomal dominant hereditary demyelinating motor and sensory neuropathy characterized by progressive distal muscle weakness and atrophy, distal sensory impairment, and decreased or absent reflexes in the affected limbs, with an onset in the first or second decade of life. Median motor nerve conduction velocities are typically less than 38 m/s. Patients often have foot deformities. Sural nerve biopsy shows decrease in myelinated fibers, myelin abnormalities, and onion bulb formation. Fatty replacement of muscle tissue predominantly affects the anterior and lateral compartment of the lower legs.
Definition from the Mondo Disease Ontology (MONDO:0033135), read 2026-09-29. CC BY 4.0.
- Inheritance
- Autosomal dominant inheritance
- Onset and course
- Juvenile onset · Slowly progressive · Early young adult onset
HPO, annotations 2026-09-02
Features
17 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.
- Decreased compound muscle action potential amplitudeHPOHP:0033383
- 1 of 1 reported patient
- Distal amyotrophyHPOHP:0003693
- 4 of 4 reported patients
- Distal lower limb muscle weaknessHPOHP:0009053
- 3 of 3 reported patients
- Distal muscle weaknessHPOHP:0002460
- 1 of 1 reported patient
- Distal sensory impairmentHPOHP:0002936
- 1 of 1 reported patient
- Fatty replacement of skeletal muscleHPO
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.
- PMP2HGNC:9117
- Strong · Labcorp Genetics (formerly Invitae) · Autosomal dominant · 2021
- Moderate · Ambry Genetics · Autosomal dominant · 2018
- Moderate · PanelApp Australia · Autosomal dominant · 2025
- Supportive · Orphanet · Autosomal dominant · 2021
Where it sits
Other names
2 names
Resolves to: Charcot-Marie-Tooth disease, demyelinating, type 1G
- Also called
- CMT1GPMP2-related Charcot-Marie-Tooth disease type 1