| Neurofilament Medium (NFM) | |
|---|---|
| Gene | [NEFM](/genes/nefm) |
| UniProt ID | [P07197](https://www.uniprot.org/uniprot/P07197) |
| PDB | 6YJG (segment), AlphaFold model |
| Molecular Weight | 150-160 kDa |
| Localization | Neuronal cytoplasm, axons |
| Family | Type IV intermediate filament family |
| Disease | AD, PD, ALS, Charcot-Marie-Tooth |
Neurofilament medium (NFM, NEFM) is a 150-160 kDa intermediate filament protein that forms part of the neuronal cytoskeleton. Along with neurofilament light (NFL) and heavy (NFH) chains, NFM is essential for axonal structure, caliber, and transport. NFM levels in CSF are emerging as biomarkers for neurodegenerative disease progression and treatment response.
NFM has the characteristic intermediate filament architecture:
Key structural features:
Neurofilament assembly:
Neurofilaments have critical neuronal functions:
Phosphorylation of NFM KSP repeats:
NFM in CSF is a validated neurodegeneration biomarker[2]:
| Disease | CSF NFM Level |
|---|---|
| ALS | ↑↑↑ (very high) |
| AD | ↑↑ |
| PD | ↑ (moderate) |
| FTD | ↑↑ |
| MS | ↑ (during relapses) |
Clinical utility:
NFM in ALS pathophysiology:
NFM in AD:
NEFM mutations linked to CMT:
NFM levels track disease activity in MS models[3].
| Strategy | Mechanism | Status |
|---|---|---|
| Neurofilament protection | Axonal stabilizers | Preclinical |
| Biomarker monitoring | Disease tracking | Clinical use |
| CSF NFM assays | Diagnostic/prognostic | FDA cleared (research) |
Yuan et al. Neurofilament structure and function. Nat Rev Neurosci. 2017. ↩︎
Khalil et al. Neurofilaments as biomarkers in neurological disorders. Nat Rev Neurol. 2018. ↩︎