FANCM Gene

📖 Wiki Page

gene1683 wordssynced 2026-04-02

FANCM Gene

<table class="infobox infobox-gene">
<tr>
<th class="infobox-header" colspan="2">FANCM Gene</th>
</tr>
<tr>
<td class="label">Symbol</td>
<td>FANCM</td>
</tr>
<tr>
<td class="label">Full Name</td>
<td>Fanconi Anemia Group M</td>
</tr>
<tr>
<td class="label">Chromosomal Location</td>
<td>7q22.3</td>
</tr>
<tr>
<td class="label">NCBI Gene ID</td>
<td>57697</td>
</tr>
<tr>
<td class="label">OMIM ID</td>
<td>609644</td>
</tr>
<tr>
<td class="label">Ensembl ID</td>
<td>ENSG00000187240</td>
</tr>
<tr>
<td class="label">UniProt ID</td>
<td>Q8IWA5</td>
</tr>
<tr>
<td class="label">Protein Length</td>
<td>1252 amino acids</td>
</tr>
<tr>
<td class="label">Molecular Weight</td>
<td>~140 kDa</td>
</tr>
<tr>
<td class="label">Expression</td>
<td>Ubiquitous (high in proliferating tissues, brain, bone marrow)</td>
</tr>
<tr>
<td class="label">Associated Diseases</td>
<td>Fanconi anemia, breast cancer, AD, PD, ataxia</td>
</tr>
<tr>
<td class="label">Approach</td>
<td>Mechanism</td>
</tr>
<tr>
<td class="label">FANCM expression enhancement</td>
<td>Increase FANCM levels via AAV or small molecules</td>
</tr>
<tr>
<td class="label">FA pathway activators</td>
<td>Small molecules that activate FANCD2 monoubiquitination</td>
</tr>
<tr>
<td class="label">Checkpoint inhibition</td>
<td>ATM/ATR inhibitors to promote repair</td>
</tr>
<tr>

...

FANCM Gene

FANCM (Fanconi Anemia Group M) encodes a DNA translocase and central initiator of the Fanconi anemia (FA) DNA damage response pathway. FANCM plays essential roles in interstrand crosslink (ICL) repair, replication fork remodeling and stabilization, and the maintenance of genomic stability. Loss of FANCM function leads to Fanconi anemia with bone marrow failure and cancer predisposition, while partial deficiency or variants may contribute to neurodegeneration through accumulated DNA damage in post-mitotic [neurons](/entities/neurons)[@meetei2005][@zhang2020].

Overview

Gene Structure

The FANCM gene spans approximately 20 kb on chromosome 7q22.3 and contains 22 exons. The gene encodes a multi-domain protein with DNA translocase activity that serves as the initial sensor of DNA damage in the FA pathway[@meetei2005].

Protein Structure and Function

Domain Architecture

FANCM contains several functional domains[@meetei2005][@gari2008]:

N-terminal ERCC4 nuclease domain: Similar to structure-specific endonucleases (XPF/MUS81 family)

Helicase domain: SF2 helicase superfamily with ATP-dependent DNA unwinding activity

MM1 motif: Mutation cluster region important for function

C-terminal FAAP24-binding domain: Dimerization and recruitment to DNA damage sites

EA motif: Required for interaction with the FA core complex

Translocase Activity

FANCM is a DNA translocase that moves along DNA, unwinding secondary structures and detecting damage[@gari2008][@liu2010]:

Directional movement: FANCM translocates in a 5' to 3' direction relative to the bound strand
DNA unwinding: ATP-dependent helicase activity unwinds duplex DNA
Damage detection: Stalls at DNA interstrand crosslinks and other lesions
Fork remodeling: Can branch migrate replication forks to expose and process ICLs

Normal Physiological Function

Fanconi Anemia Pathway

The FA pathway is the primary mechanism for repairing DNA interstrand crosslinks, which are among the most cytotoxic forms of DNA damage[@meetei2005][@gari2008]:

Mermaid diagram (expand to render)

Replication Fork Remodeling

FANCM remodels stalled replication forks to facilitate ICL repair[@liu2010]:

Fork stalling: When replisomes encounter ICLs, FANCM is recruited
Branch migration: FANCM translocase activity pushes the fork forward, remodeling the DNA structure
Fork protection: FANCM helps prevent excessive fork collapse and generation of toxic DNA breaks
Checkpoint activation: FANCM signals through ATR/Chk1 to activate cell cycle checkpoints

Genomic Stability Maintenance

FANCM prevents genomic instability through several mechanisms[@wang2018]:

ICL repair: Primary function in removing interstrand crosslinks from DNA
Checkpoint signaling: Activates ATM/Chk2 and ATR/Chk1 pathways in response to DNA damage
Chromosome cohesion: Cooperates with cohesion complexes to maintain chromosome integrity
Sister chromatid exchange regulation: Controls error-free vs. error-prone repair pathway choice

Disease Associations

Fanconi Anemia

Biallelic FANCM mutations cause Fanconi anemia complementation group M[@meetei2005][@che2019]:

Bone marrow failure: Progressive pancytopenia due to stem cell attrition
Congenital abnormalities: Skeletal malformations (radial ray defects), microcephaly, skin pigmentation
Cancer predisposition: High risk of acute myeloid leukemia, solid tumors (head/neck, gynecological)
Cellular phenotype: Hypersensitivity to DNA crosslinking agents (mitomycin C, diepoxybutane)
Phenotype variability: Milder than other FA subtypes due to residual FANCM function

Breast Cancer Susceptibility

FANCM variants modify breast cancer risk[@wang2018]:

Truncating variants: FANCM nonsense and frameshift variants associated with increased breast cancer risk
Population studies: Observed in ~1% of population, enriched in breast cancer cases
Mechanism: Partial loss of FANCM function impairs ICL repair, increasing genomic instability
Interaction with BRCA: FANCM works in the same pathway as BRCA1/2; variants may synergize

Alzheimer's Disease

FANCM and FA pathway dysfunction contribute to AD through accumulated DNA damage[@zhang2020][@shen2022]:

Neuronal DNA damage accumulation: Post-mitotic neurons accumulate oxidative and ICL damage over time
Impaired repair in aging: FA pathway activity declines with age, reducing ICL repair capacity
Amyloid-beta effects: Aβ induces DNA damage and may impair FA pathway components
Neurodegeneration mechanism: Unrepaired DNA damage activates apoptosis in neurons
Therapeutic relevance: Enhancing DNA repair pathways may protect neurons from Aβ toxicity[@shen2022]
Evidence: FANCM expression is altered in AD brain tissue; pathway components are dysregulated

Parkinson's Disease

DNA repair defects contribute to PD pathogenesis through several mechanisms[@che2019][@zhang2020]:

Neuronal vulnerability: Dopaminergic neurons in the [substantia nigra](/brain-regions/substantia-nigra) are particularly vulnerable to DNA damage due to high metabolic activity and oxidative stress
Mitochondrial DNA damage: PD neurons show increased mtDNA mutations; FANCM may affect mtDNA repair
Alpha-synuclein interactions: DNA damage activates signaling pathways that may promote alpha-synuclein aggregation
Parkin interaction: The E3 ubiquitin ligase Parkin (PRKN), mutated in familial PD, is involved in DNA damage response
Aging and PD: Age-related decline in DNA repair capacity is a key contributor to sporadic PD risk
Animal models: Drosophila models with FANCM deficiency show neurodegeneration and motor dysfunction[@kelsky2021]

Ataxia and Neurological Dysfunction

FANCM variants can cause non-FA neurological presentations:

Ataxia: Progressive cerebellar ataxia with or without typical FA features
Neuropathy: Peripheral neuropathy and motor dysfunction
Cognitive impairment: Learning disabilities and reduced cognitive function
Mechanism: Partial FANCM deficiency impairs neuronal DNA repair without causing full FA phenotype

Therapeutic Implications

DNA Repair Enhancement

Approaches to enhance FANCM/FA pathway function in neurodegeneration[@shen2022][@zhang2020]:

Clinical Trials in DNA Repair

Neuroprotective Strategies

Specific neuroprotection approaches[@zhang2020][@shen2022]:

Reduce DNA damage burden: Antioxidants, mitochondrial protectants
Enhance repair capacity: Increase expression of FA pathway components
Cell survival signaling: Activate neurotrophic pathways when DNA damage is detected
Stem cell approaches: FA pathway-enhanced neural stem cells for cell replacement

Animal Models

Fancm Knockout Mice

Partial lethality: Homozygous knockouts show embryonic or neonatal death in some backgrounds
FA phenotype: Mitomycin C hypersensitivity, reduced fertility, mild anemia
Cancer predisposition: Increased tumor formation with age
Neurodegeneration: Progressive motor deficits and neuronal loss in older mice
Conditional knockouts: Neuron-specific deletion to study CNS effects

Drosophila Models

Drosophila with FANCM knockdown show[@kelsky2021]:

Neurodegeneration: Progressive loss of dopaminergic neurons
Motor dysfunction: Climbing deficits and reduced lifespan
Genomic instability: Increased DNA damage markers in neurons
Genetic interactions: Synergy with Parkin and PINK1 mutations
Rescue by human FANCM: Expression of human FANCM rescues Drosophila phenotype

Disease Models

Zebrafish Fancm morphants: Developmental abnormalities and DNA repair defects
Cellular models: FANCM-deficient iPSC-derived neurons show increased DNA damage

Signaling Pathways and Interactions

Protein Interactions

FANCM interacts with multiple FA pathway and DNA repair proteins[@meetei2005][@gari2008]:

FA core complex: FANCA, FANCB, FANCC, FANCE, FANCF, FANCG, FANCL form the core complex recruited by FANCM
FAAP24: Forms a heterodimer with FANCM, directing it to duplex DNA structures
FANCD2-FANCI (ID complex): FANCM promotes monoubiquitination of this heterodimer
ATR-ATRIP: FANCM recruits checkpoint kinase to stalled replication forks
BLM (Bloom syndrome): FANCM coordinates with BLM helicase in fork processing
RAD51: FANCM regulates homologous recombination-mediated fork restart

DNA Damage Response

FANCM activates multiple DNA damage response pathways[@zhang2020]:

ATR/Chk1 pathway: Primary checkpoint for replication stress and ICLs
ATM/Chk2 pathway: Activated by double-strand breaks from fork collapse
p53 pathway: Long-term DNA damage leads to p53-mediated cell cycle arrest or apoptosis
NF-kB pathway: DNA damage activates pro-survival NF-kB signaling

Research Directions

Current Priorities

Key research areas for FANCM include[@zhang2020][@shen2022][@che2019]:

Neuronal DNA repair: Understanding how FANCM and FA pathway function in post-mitotic neurons

Aging and DNA repair decline: Mechanisms of age-related decline in FA pathway activity

Therapeutic targeting: Developing drugs that enhance FANCM/FA pathway function in the brain

Biomarker development: FANCM activity as a marker of neuronal DNA repair capacity

Genetic interactions: How FANCM variants interact with other neurodegeneration risk genes

Combination approaches: DNA repair enhancement with existing neuroprotective strategies

Emerging Questions

Does FANCM deficiency accelerate Alzheimer's or Parkinson's disease progression?
Can small molecules enhance FANCM function or FA pathway activity in neurons?
What is the relative contribution of mitochondrial vs. nuclear DNA damage in neurodegeneration?
Are there neuroprotective interventions that bypass FANCM deficiency?

Summary

FANCM encodes a DNA translocase that initiates the Fanconi anemia DNA damage response pathway, essential for repairing interstrand crosslinks and maintaining genomic stability. Loss of FANCM causes Fanconi anemia with bone marrow failure and cancer predisposition, while partial deficiency or variants may contribute to Alzheimer's and Parkinson's disease through accumulated DNA damage in vulnerable neurons. Enhancing DNA repair pathways through FANCM or downstream effectors represents a therapeutic strategy to protect neurons from age-related and disease-related DNA damage accumulation.

External Links

[FANCM - NCBI Gene](https://www.ncbi.nlm.nih.gov/gene/57697)
[FANCM Protein - UniProt](https://www.uniprot.org/uniprot/Q8IWA5)
[FANCM - GeneCards](https://www.genecards.org/cgi-bin/carddisp.pl?gene=FANCM)
[OMIM: 609644](https://www.omim.org/entry/609644)
[Ensembl: ENSG00000187240](https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000187240)

📖 View canonical wiki page →

FANCM Gene

FANCM Gene

FANCM Gene

Overview

Gene Structure

Protein Structure and Function

Domain Architecture

Translocase Activity

Normal Physiological Function

Fanconi Anemia Pathway

Replication Fork Remodeling

Genomic Stability Maintenance

Disease Associations

Fanconi Anemia

Breast Cancer Susceptibility

Alzheimer's Disease

Parkinson's Disease

Ataxia and Neurological Dysfunction

Therapeutic Implications

DNA Repair Enhancement

Clinical Trials in DNA Repair

Neuroprotective Strategies

Animal Models

Fancm Knockout Mice

Drosophila Models

Disease Models

Signaling Pathways and Interactions

Protein Interactions

DNA Damage Response

Research Directions

Current Priorities

Emerging Questions

Summary

See Also

External Links