Young infants with PMP22 duplication can have minor nerve conduction study abnormalities
Jean-Baptiste Davion1, François Cassim2, Yann Péréon3
1Centre de référence des Maladies Neuromusculaires, CHU Lille, Lille, France; Service de Neurologie pédiatrique, CHU Lille, France.
Neurophysiologie Clinique = Clinical Neurophysiology
|October 17, 2022
Summary
Normal nerve conduction studies (NCS) can occur in infants with Charcot-Marie-Tooth disease type 1A (CMT1A). Delayed electrodiagnostic testing (EDX) abnormalities in CMT1A patients may impact early diagnosis and clinical trials.
Area of Science:
- Neurology
- Genetics
- Biochemistry
Background:
- Charcot-Marie-Tooth disease type 1A (CMT1A) is a genetic peripheral neuropathy caused by PMP22 gene duplication.
- Electrodiagnostic testing (EDX) in CMT1A typically shows demyelination, including slowed nerve conduction velocities and prolonged distal latencies.
Observation:
- Abnormalities on EDX are often less pronounced in infants under two years old.
- The possibility of normal nerve conduction studies (NCS) in infants under one year with CMT1A has been debated.
Findings:
- This study reports three infants diagnosed with CMT1A who presented with normal or near-normal NCS.
- These findings suggest that EDX abnormalities in CMT1A may not be apparent at birth or in early infancy.
Implications:
- Delayed presentation of EDX abnormalities in CMT1A can complicate early diagnosis in infants.
- These findings are crucial for designing and interpreting results from clinical trials targeting early-stage CMT1A.
