FA2H Gene

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FA2H Gene

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FA2H Gene

<table class="infobox infobox-gene">
<tr>
<th class="infobox-header" colspan="2">fa2h</th>
</tr>
<tr>
<td class="label">Lipid Type</td>
<td>Structure</td>
</tr>
<tr>
<td class="label">2-OH galactosylceramide</td>
<td>Galactose-2-OH FA-ceramide</td>
</tr>
<tr>
<td class="label">2-OH glucosylceramide</td>
<td>Glucose-2-OH FA-ceramide</td>
</tr>
<tr>
<td class="label">2-OH sulfatide</td>
<td>Sulfate-2-OH FA-ceramide</td>
</tr>
<tr>
<td class="label">2-OH ceramide</td>
<td>Base-2-OH FA</td>
</tr>
<tr>
<td class="label">Variant Type</td>
<td>Effect</td>
</tr>
<tr>
<td class="label">Missense</td>
<td>Partial enzyme loss</td>
</tr>
<tr>
<td class="label">Nonsense</td>
<td>Truncated protein</td>
</tr>
<tr>
<td class="label">Frameshift</td>
<td>No functional protein</td>
</tr>
<tr>
<td class="label">Splice site</td>
<td>Exon skipping</td>
</tr>
<tr>
<td class="label">Method</td>
<td>Application</td>
</tr>
<tr>
<td class="label">Panel testing</td>
<td>Known HSP genes</td>
</tr>
<tr>
<td class="label">Whole exome sequencing</td>
<td>Novel variant discovery</td>
</tr>
<tr>
<td class="label">Whole genome sequencing</td>
<td>Regulatory variants</td>
</tr>
<tr>
<td class="label">Segregation analysis</td>
<td>Family studies</td>
</tr>
<tr>
<td class="label">Model</td>
<td>Species</td>
</tr>
<tr>
<td class="label">Fa2h knockout</td>
<td>Mouse</td>
</tr>
<tr>
<td cl

...

FA2H Gene

<table class="infobox infobox-gene">
<tr>
<th class="infobox-header" colspan="2">fa2h</th>
</tr>
<tr>
<td class="label">Lipid Type</td>
<td>Structure</td>
</tr>
<tr>
<td class="label">2-OH galactosylceramide</td>
<td>Galactose-2-OH FA-ceramide</td>
</tr>
<tr>
<td class="label">2-OH glucosylceramide</td>
<td>Glucose-2-OH FA-ceramide</td>
</tr>
<tr>
<td class="label">2-OH sulfatide</td>
<td>Sulfate-2-OH FA-ceramide</td>
</tr>
<tr>
<td class="label">2-OH ceramide</td>
<td>Base-2-OH FA</td>
</tr>
<tr>
<td class="label">Variant Type</td>
<td>Effect</td>
</tr>
<tr>
<td class="label">Missense</td>
<td>Partial enzyme loss</td>
</tr>
<tr>
<td class="label">Nonsense</td>
<td>Truncated protein</td>
</tr>
<tr>
<td class="label">Frameshift</td>
<td>No functional protein</td>
</tr>
<tr>
<td class="label">Splice site</td>
<td>Exon skipping</td>
</tr>
<tr>
<td class="label">Method</td>
<td>Application</td>
</tr>
<tr>
<td class="label">Panel testing</td>
<td>Known HSP genes</td>
</tr>
<tr>
<td class="label">Whole exome sequencing</td>
<td>Novel variant discovery</td>
</tr>
<tr>
<td class="label">Whole genome sequencing</td>
<td>Regulatory variants</td>
</tr>
<tr>
<td class="label">Segregation analysis</td>
<td>Family studies</td>
</tr>
<tr>
<td class="label">Model</td>
<td>Species</td>
</tr>
<tr>
<td class="label">Fa2h knockout</td>
<td>Mouse</td>
</tr>
<tr>
<td class="label">Conditional KO</td>
<td>Mouse</td>
</tr>
<tr>
<td class="label">Knock-in</td>
<td>Mouse</td>
</tr>
<tr>
<td class="label">Transgenic</td>
<td>Zebrafish</td>
</tr>
<tr>
<td class="label">Protein</td>
<td>Change</td>
</tr>
<tr>
<td class="label">MBP</td>
<td>Reduced</td>
</tr>
<tr>
<td class="label">PLP1</td>
<td>Normal</td>
</tr>
<tr>
<td class="label">CNP</td>
<td>Increased</td>
</tr>
<tr>
<td class="label">MAG</td>
<td>Reduced</td>
</tr>
<tr>
<td class="label">Oligodendrocyte markers</td>
<td>Variable</td>
</tr>
<tr>
<td class="label">Condition</td>
<td>Distinguishing Features</td>
</tr>
<tr>
<td class="label">SPG4 (SPAST)</td>
<td>Pure spasticity, no cognitive</td>
</tr>
<tr>
<td class="label">SPG15 (ZFYVE19)</td>
<td>Thin corpus callosum, cognitive</td>
</tr>
<tr>
<td class="label">Metachromatic leukodystrophy</td>
<td>ARSA mutations</td>
</tr>
<tr>
<td class="label">Krabbe disease</td>
<td>GALC deficiency</td>
</tr>
<tr>
<td class="label">Adrenoleukodystrophy</td>
<td>VLCFA elevation</td>
</tr>
<tr>
<td class="label">Stage</td>
<td>Age</td>
</tr>
<tr>
<td class="label">Pre-symptomatic</td>
<td>Birth-5 years</td>
</tr>
<tr>
<td class="label">Early</td>
<td>5-15 years</td>
</tr>
<tr>
<td class="label">Intermediate</td>
<td>15-30 years</td>
</tr>
<tr>
<td class="label">Late</td>
<td>30+ years</td>
</tr>
<tr>
<td class="label">Specialty</td>
<td>Role</td>
</tr>
<tr>
<td class="label">Neurology</td>
<td>Primary care, medication</td>
</tr>
<tr>
<td class="label">Orthopedics</td>
<td>Contracture management</td>
</tr>
<tr>
<td class="label">Physical therapy</td>
<td>Mobility, function</td>
</tr>
<tr>
<td class="label">Occupational therapy</td>
<td>ADL optimization</td>
</tr>
<tr>
<td class="label">Psychology</td>
<td>Cognitive support</td>
</tr>
<tr>
<td class="label">Urology</td>
<td>Bladder management</td>
</tr>
<tr>
<td class="label">Factor</td>
<td>Prognostic Value</td>
</tr>
<tr>
<td class="label">Age at onset</td>
<td>Earlier = more severe</td>
</tr>
<tr>
<td class="label">Cognitive involvement</td>
<td>Worsens prognosis</td>
</tr>
<tr>
<td class="label">Ambulation status</td>
<td>Preserved = better</td>
</tr>
<tr>
<td class="label">Comorbidities</td>
<td>Additional burden</td>
</tr>
<tr>
<td class="label">Variant Type</td>
<td>Mechanism</td>
</tr>
<tr>
<td class="label">Missense</td>
<td>Partial loss</td>
</tr>
<tr>
<td class="label">Nonsense</td>
<td>Truncated protein</td>
</tr>
<tr>
<td class="label">Frameshift</td>
<td>No protein</td>
</tr>
<tr>
<td class="label">Splice site</td>
<td>Exon skipping</td>
</tr>
<tr>
<td class="label">Deletion</td>
<td>No protein</td>
</tr>
<tr>
<td class="label">Variant</td>
<td>Effect</td>
</tr>
<tr>
<td class="label">p.Gln214*</td>
<td>Nonsense</td>
</tr>
<tr>
<td class="label">p.Arg270Cys</td>
<td>Missense</td>
</tr>
<tr>
<td class="label">p.Tyr365Asn</td>
<td>Missense</td>
</tr>
<tr>
<td class="label">c.634+1G>A</td>
<td>Splicing</td>
</tr>
<tr>
<td class="label">Domain</td>
<td>Variants</td>
</tr>
<tr>
<td class="label">Transmembrane</td>
<td>Common</td>
</tr>
<tr>
<td class="label">Catalytic domain</td>
<td>Severe</td>
</tr>
<tr>
<td class="label">C-terminal</td>
<td>Mild</td>
</tr>
<tr>
<td class="label">System</td>
<td>Finding</td>
</tr>
<tr>
<td class="label">Dermatological</td>
<td>Dry skin</td>
</tr>
<tr>
<td class="label">Ocular</td>
<td>Rare</td>
</tr>
<tr>
<td class="label">hepatic</td>
<td>Occasional</td>
</tr>
<tr>
<td class="label">Hematological</td>
<td>Rare</td>
</tr>
<tr>
<td class="label">Organization</td>
<td>Focus</td>
</tr>
<tr>
<td class="label">Spastic Paraplegia Foundation</td>
<td>HSP</td>
</tr>
<tr>
<td class="label">NIH NINDS</td>
<td>Neurological</td>
</tr>
<tr>
<td class="label">Genetic Alliance</td>
<td>Rare disease</td>
</tr>
<tr>
<td class="label">Category</td>
<td>Annual Cost</td>
</tr>
<tr>
<td class="label">Medical care</td>
<td>High</td>
</tr>
<tr>
<td class="label">Therapy</td>
<td>Moderate</td>
</tr>
<tr>
<td class="label">Assistive devices</td>
<td>Variable</td>
</tr>
<tr>
<td class="label">Medications</td>
<td>Moderate</td>
</tr>
<tr>
<td class="label">Modality</td>
<td>Target</td>
</tr>
<tr>
<td class="label">MRI</td>
<td>White matter</td>
</tr>
<tr>
<td class="label">DTI</td>
<td>Tract integrity</td>
</tr>
<tr>
<td class="label">PET</td>
<td>Inflammation</td>
</tr>
<tr>
<td class="label">MRS</td>
<td>Lipid metabolism</td>
</tr>
<tr>
<td class="label">Vector</td>
<td>Tropism</td>
</tr>
<tr>
<td class="label">AAV9</td>
<td>CNS</td>
</tr>
<tr>
<td class="label">AAVrh.10</td>
<td>Neurons</td>
</tr>
<tr>
<td class="label">Lentivirus</td>
<td>Integration</td>
</tr>
<tr>
<td class="label">Non-viral</td>
<td>Safety</td>
</tr>
<tr>
<td class="label">Target</td>
<td>Drug Class</td>
</tr>
<tr>
<td class="label">Spasticity</td>
<td>GABA-B agonist</td>
</tr>
<tr>
<td class="label">Seizures</td>
<td>Antiepileptic</td>
</tr>
<tr>
<td class="label">Pain</td>
<td>Analgesics</td>
</tr>
<tr>
<td class="label">Mood</td>
<td>Psychotropics</td>
</tr>
<tr>
<td class="label">Test</td>
<td>Purpose</td>
</tr>
<tr>
<td class="label">MRI brain</td>
<td>Structural assessment</td>
</tr>
<tr>
<td class="label">MR spectroscopy</td>
<td>Metabolic profiling</td>
</tr>
<tr>
<td class="label">Nerve conduction</td>
<td>Peripheral nerve</td>
</tr>
<tr>
<td class="label">Genetic testing</td>
<td>Confirmation</td>
</tr>
<tr>
<td class="label">CSF analysis</td>
<td>Biomarkers</td>
</tr>
<tr>
<td class="label">Finding</td>
<td>Age of Onset</td>
</tr>
<tr>
<td class="label">Hypomyelination</td>
<td>P14</td>
</tr>
<tr>
<td class="label">Axonal loss</td>
<td>6 months</td>
</tr>
<tr>
<td class="label">Gliosis</td>
<td>3 months</td>
</tr>
<tr>
<td class="label">Inflammation</td>
<td>6 months</td>
</tr>
<tr>
<td class="label">Neuronal loss</td>
<td>12 months</td>
</tr>
<tr>
<td class="label">Method</td>
<td>Stage</td>
</tr>
<tr>
<td class="label">Enzyme assays</td>
<td>In vitro</td>
</tr>
<tr>
<td class="label">Cell-based screens</td>
<td>In vitro</td>
</tr>
<tr>
<td class="label">Animal models</td>
<td>In vivo</td>
</tr>
<tr>
<td class="label">Patient iPSCs</td>
<td>Ex vivo</td>
</tr>
<tr>
<td class="label">Region</td>
<td>Expression Level</td>
</tr>
<tr>
<td class="label">Corpus callosum</td>
<td>High</td>
</tr>
<tr>
<td class="label">Cerebral cortex</td>
<td>Medium-High</td>
</tr>
<tr>
<td class="label">Cerebellum</td>
<td>Medium</td>
</tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/dystonia" style="color:#ef9a9a">Dystonia</a>, <a href="/wiki/ms" style="color:#ef9a9a">Ms</a>, <a href="/wiki/neurodegeneration" style="color:#ef9a9a">Neurodegeneration</a>, <a href="/wiki/parkinson" style="color:#ef9a9a">Parkinson</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">15 edges</a></td>
</tr>
</table>

Pathway / Mechanism Diagram

Mermaid diagram (expand to render)

Overview

FA2H is a human gene. This page covers the gene's normal function, disease associations, expression patterns, and key research findings relevant to neurodegeneration. [@wang2017]

FA2H (Fatty Acid 2-Hydroxylase) encodes a transmembrane enzyme localized to the endoplasmic reticulum that catalyzes the 2-hydroxylation of fatty acids, producing 2-hydroxy fatty acids (2-OH FAs) that are essential components of myelin lipids. The FA2H enzyme plays a critical role in lipid metabolism, particularly in the synthesis of 2-hydroxy galactosylceramide and 2-hydroxy glucosylceramide, which are enriched in the myelin sheath. Pathogenic variants in FA2H cause hereditary spastic paraplegia (HSP) type 35 (SPG35) and have been implicated in neurodegeneration through disruptions of lipid metabolism, oxidative stress, and neuroinflammation. The gene is located on chromosome 16q23.1 and consists of 13 exons. [@keller2019]

Gene Structure and Protein Function

Enzyme Architecture

FA2H is a member of the fatty acid hydroxylase family characterized by: [@snaidero2020]

Topology: Multiple transmembrane domains spanning the ER membrane
Active site: Cytoplasmic-facing catalytic domain containing the diiron center
Cofactor requirement: Iron and oxygen for hydroxylation reaction
Substrate specificity: Preferential activity toward C16-C24 fatty acyl-CoA substrates

Catalytic Mechanism

The 2-hydroxylation reaction proceeds through: [@nave2014]

Substrate (fatty acyl-CoA) binding to the active site

Oxygen binding to the diiron center

Hydrogen abstraction from the C2 position

Hydroxyl radical addition to generate 2-hydroxy fatty acid

Product release and CoA recycling

Lipid Products

FA2H produces 2-hydroxy fatty acids that are incorporated into: [@simons2013]

Biological Role in the Nervous System

Myelin Composition

The myelin sheath contains exceptionally high concentrations of 2-hydroxy fatty acids: [@kutz2015]

2-hydroxygalactosylceramide comprises ~30% of myelin galactolipids
These lipids stabilize myelin structure through hydrogen bonding
2-OH groups enhance lipid packing and membrane cohesion
Loss of 2-hydroxylation disrupts myelin ultrastructure

Oligodendrocyte Function

FA2H is highly expressed in oligodendrocyte precursor cells (OPCs) and maturing oligodendrocytes: [@bergles2015]

Required for proper myelin sheath formation during development
Maintains myelin lipid composition in adult CNS
Supports myelin repair following demyelination
Dysregulation leads to hypomyelination

Axonal Support

Beyond myelin formation, FA2H supports axonal health through: [@trapp2018]

Regulation of lipid raft composition
Modulation of neurotrophin signaling
Protection against oxidative stress
Maintenance of axonal transport

Clinical Significance

Hereditary Spastic Paraplegia Type 35 (SPG35)

Biallelic pathogenic variants in FA2H cause autosomal recessive SPG35: [@bradl2010]

Clinical Features

Progressive lower limb spasticity and weakness
Cognitive impairment in ~40% of cases
Peripheral neuropathy in some patients
Onset typically in childhood or adolescence
Variable progression rate

Neuroimaging Findings

Thin corpus callosum
White matter abnormalities on MRI
Cerebral atrophy in severe cases
Cerebellar involvement in some variants

Genotype-Phenotype Correlations

Parkinson's Disease Association

Emerging evidence links FA2H to Parkinson's disease:

Genetic Findings

Rare missense variants identified in PD patients
Expression changes in PD substantia nigra
Meta-analysis suggests modest risk contribution
Possible interaction with alpha-synuclein metabolism

Mechanistic Links

Lipid dysregulation affects alpha-synuclein aggregation
Impaired myelin maintenance in PD substantia nigra
Altered fatty acid metabolism in dopamine neurons
Inflammation-related pathway disruption

Other Neurological Associations

Multiple sclerosis: Altered FA2H expression in lesions
Metachromatic leukodystrophy: Potential modifier gene
Alexander disease: Possible lipid metabolism involvement
Amyotrophic lateral sclerosis: Rare variant associations

Molecular Mechanisms of Pathogenesis

Loss of Function Mechanisms

FA2H deficiency leads to neurodegeneration through:

Myelin Instability

Reduced 2-hydroxy galactolipid content
Structural myelin abnormalities
Impaired conduction velocity
Secondary axonal degeneration

Lipid Raft Dysregulation

Altered membrane microdomain composition
Disrupted signaling platform function
Impaired neurotrophin receptor trafficking
Altered ion channel localization

ER Stress

Accumulation of unmetabolized substrates
Unfolded protein response activation
Calcium homeostasis disruption
Pro-apoptotic signaling

Altered Lipid Metabolism

Pathogenic variants disrupt lipid homeostasis:

Accumulation of non-hydroxy fatty acids
Reduced sulfatide content
Impaired cholesterol trafficking
Altered ganglioside composition

Neuroinflammation

FA2H deficiency triggers inflammatory responses:

Microglial activation in white matter
Cytokine release (IL-1β, TNF-α)
Complement system activation
Autoimmune-like demyelination

Diagnosis and Testing

Genetic Testing

Molecular diagnosis involves:

Biomarker Analysis

Elevated CSF sulfatide in FA2H deficiency
Abnormal very-long-chain fatty acid profile
Reduced 2-hydroxy fatty acids in serum
Neurofilament light chain elevation

Neuroimaging

Diagnostic imaging findings:

MRI: White matter hyperintensities, thin corpus callosum
MRS: Reduced N-acetylaspartate in affected regions
DTI: Reduced fractional anisotropy in white matter tracts

Therapeutic Approaches

Small Molecule Therapies

Current pharmacological strategies:

Lactoferrin: Promotes oligodendrocyte differentiation
Clemastine: Promotes remyelination via M1R antagonism
Benznidazole: Potential for enhancing 2-hydroxylation
Antioxidants: Counteract oxidative stress

Gene Therapy

Emerging therapeutic modalities:

AAV-mediated FA2H delivery to CNS
Lentiviral vector-based gene correction
CRISPR-Cas9 for precise variant editing
mRNA delivery for protein replacement

Lipid Supplementation

Dietary approaches under investigation:

2-Hydroxy fatty acid supplementation
Galactolipid-enriched diets
Omega-3 fatty acid co-therapy
Lipid raft stabilizers

Cell-Based Therapies

OPC transplantation strategies
Induced pluripotent stem cell (iPSC) models
Small molecule screening for enhancers

Research Models

Animal Models

Cellular Models

Primary oligodendrocyte cultures
iPSC-derived neurons and glia
HEK293 overexpression systems
Patient fibroblast lines

Interaction Network

Protein Partners

FA2H interacts with key proteins:

CYP4F2: Parallel fatty acid hydroxylation
GALC: Galactolipid metabolism
NG2: Proteoglycan in OPCs
PLP1: Myelin protein integration
MBP: Myelin basic protein

Signaling Pathways

FA2H influences multiple pathways:

PI3K/Akt/mTOR signaling
MAPK/ERK pathways
JAK/STAT signaling
PPARγ-mediated transcription
LXR/RXR lipid sensing

Genetic Interactions

Modifying genes in FA2H-related disease:

GALC: Substrate accumulation
ARSA: Sulfatide metabolism
SLC33A1: Acetyl-CoA transport
ELOVL1: Very-long-chain FA synthesis

Epidemiology

Prevalence

SPG35: ~1-2% of recessive HSP cases
FA2H in PD: Rare variants, unclear contribution
Compound heterozygotes more common than homozygotes
Founder mutations in specific populations

Geographic Distribution

Higher prevalence in populations with founder effects
Reported cases across Europe, Asia, Middle East
Consanguinity increases incidence
Variable phenotype expressivity

Summary

The FA2H gene encodes a critical enzyme for myelin lipid metabolism, producing 2-hydroxy fatty acids essential for proper myelin structure and function. Pathogenic variants cause hereditary spastic paraplegia type 35 (SPG35), characterized by progressive lower limb spasticity, cognitive impairment, and white matter abnormalities. The enzyme's role in lipid metabolism and myelin maintenance has also implicated FA2H in Parkinson's disease, multiple sclerosis, and other neurodegenerative conditions. Understanding FA2H function provides insights into myelin biology, lipid homeostasis, and potential therapeutic approaches for disorders of myelin maintenance and neurodegeneration.

Extended Research Findings

Proteomic Studies

Recent proteomic analyses of FA2H-deficient models reveal:

Metabolomic Analysis

Metabolomic profiling shows:

Accumulation of non-hydroxy fatty acids
Reduced 2-hydroxy galactosylceramide
Elevated very-long-chain fatty acids
Altered phospholipid composition
Changes in cholesterol metabolites

Epigenetic Regulation

FA2H expression is regulated by:

Promoter methylation: Tissue-specific expression
Histone modifications: Active marks in oligodendrocytes
Transcription factors: Olig2, Sox10, Nfat
mRNA stability: AU-rich elements in 3'UTR

Clinical Management

Diagnostic Approach

Differential Diagnosis

FA2H-related disorders must be differentiated from other causes of spasticity and white matter disease:

Natural History

Disease Progression

The clinical course of FA2H-related HSP follows predictable stages:

Complications

Contractures: Joint immobilization
Scoliosis: Spinal deformity
UTI: Recurrent infections
Respiratory: Reduced mobility complications
Cognitive: Variable decline

Long-Term Management

Multidisciplinary Care

Assistive Devices

Mobility aids: Canes, walkers, wheelchairs
Orthotics: Ankle-foot braces
Communication: Adaptive devices as needed
Home modifications: Ramps, bars

Prognosis

Life Expectancy

Generally normal with modern care
Reduced in severe cases with complications
Quality of life depends on mobility and cognition

Outcome Predictors

Molecular Genetics

Gene Structure

FA2H gene organization:

Location: 16q23.1
Genomic size: ~13 kb
Exons: 13
Transcript: NM_024072.4
Protein: NP_077045.2 (383 aa)

Variant Types

Common Variants

Genotype-Phenotype Correlations

Variant Location Effects

Pathophysiology

Cellular Mechanisms

Oligodendrocyte Death

FA2H deficiency leads to oligodendrocyte apoptosis:

Lipid accumulation triggers ER stress

Unfolded protein response activates

Calcium homeostasis disrupted

Pro-apoptotic signals triggered

Cell death follows

Myelin Breakdown

Reduced 2-hydroxy lipids destabilize myelin
Compact myelin structure disrupted
Axonal support compromised
Secondary axonal degeneration

Neuroinflammatory Mechanisms

Microglial Activation

Activated microglia release:

TNF-α: Pro-inflammatory
IL-1β: Cytokine cascade
IL-6: Acute phase response
ROS: Oxidative stress
NO: Nitrosative stress

Blood-Brain Barrier

BBB disruption in severe cases
Peripheral immune cell infiltration
Increased complement proteins
Autoimmune responses

Systemic Manifestations

Extra-neurological Involvement

Patient Support

Advocacy Organizations

Research Participation

Clinical Trials

Recruitment: Actively recruiting
Endpoints: Motor function, MRI
Duration: 12-24 months
Locations: Specialized centers

Registries

HSP Research Registry: Patient database
Rare Diseases Registry: Natural history
Genomic registries: Variant databases

Economic Considerations

Healthcare Costs

Insurance Considerations

Coverage: Variable by plan
Prior authorization: Often required
Appeals: May be necessary
Support programs: Manufacturer, foundation

Future Research Directions

Biomarker Development

Fluid Biomarkers

2-hydroxy fatty acids: Direct measure
Sulfatides: Indirect marker
Neurofilament: Disease progression
Cytokines: Inflammation

Imaging Biomarkers

Gene Therapy Advances

Viral Vectors

Delivery Routes

Intrathecal: Direct CNS delivery
Intravenous: Crosses BBB
Intranasal: Non-invasive
Stereotactic: Targeted

Small Molecule Approaches

Enzyme Replacement

Substrate reduction: Decrease substrate accumulation
Enzyme stabilization: Preserve function
Cofactor supplementation: Optimize activity

Symptomatic Relief

Summary

The FA2H gene encodes a critical enzyme for myelin lipid metabolism, producing 2-hydroxy fatty acids essential for proper myelin structure and function. Pathogenic variants cause hereditary spastic paraplegia type 35 (SPG35), characterized by progressive lower limb spasticity, cognitive impairment, and white matter abnormalities. The enzyme's role in lipid metabolism and myelin maintenance has also implicated FA2H in Parkinson's disease, multiple sclerosis, and other neurodegenerative conditions. Understanding FA2H function provides insights into myelin biology, lipid homeostasis, and potential therapeutic approaches for disorders of myelin maintenance and neurodegeneration.

Diagnostic Approach

Treatment Strategies

Current management includes:

Physical therapy: Maintain mobility, prevent contractures

Occupational therapy: Adaptive equipment

Speech therapy: If cognitive involvement

Seizure management: Antiepileptic drugs as needed

Orthopedic interventions: Spasticity management

Experimental Therapies

Emerging treatments under investigation:

Gene replacement: AAV-FA2H delivery
Enzyme enhancement: Small molecule activators
Lipid supplementation: 2-hydroxy fatty acid diets
Cell therapy: OPC transplantation
Remyelination promoters: Clemaistine, opicinumab

Animal Model Characterization

Phenotype Details

Fa2h knockout mice exhibit:

Behavioral: Tremor, ataxia, reduced movement
Neurological: Hypomyelinatior, axonal degeneration
Lifespan: Reduced compared to wild-type
Growth: Normal embryonic, postnatal delay
Fertility: Reduced in homozygotes

Histopathology

Biochemical Changes

Reduced 2-hydroxy fatty acids in brain lipids
Accumulation of non-hydroxy fatty acids
Altered ganglioside composition
Elevated cholesterol esters
Increased oxidative markers

Drug Development

Target Validation

FA2H as a therapeutic target:

Genetic validation: SPG35 phenotypes in humans
Animal model validation: Knockout phenotypes
Biomarker validation: Sulfatide levels
Safety considerations: Essential enzyme function

Screening Approaches

Clinical Trial Considerations

Patient selection: Genetically confirmed SPG35
Endpoint selection: Mobility scales, MRI
Biomarker correlation: CSF sulfatide
Duration: Likely multi-year
Combination therapy: Potential approaches

Genetic Counseling

Inheritance Pattern

FA2H disorders are autosomal recessive:

Both parents typically heterozygous carriers
25% risk for affected offspring in each pregnancy
Carrier testing available for at-risk family members
Prenatal testing possible for known variants
Preimplantation genetic diagnosis an option

Carrier Frequency

General population: Very rare
Consanguineous populations: Higher
Founder populations: Documented in specific groups
Carrier screening: Not routinely available
Population studies: Limited data

Family Planning

Options for affected families:

Prenatal diagnosis
Preimplantation genetic testing
Donor gametes
Adoption
Natural pregnancy with carrier testing

Allen Brain Atlas Data

Gene Expression

Fatty acid 2-hydroxylase (FA2H) shows high expression in:

[Cerebral cortex* - White matter and oligodendrocyte-rich regions](/brain-regions/cerebral-cortex)
[Corpus callosum* - High expression in myelinated fiber tracts](/brain-regions/corpus-callosum)
[Cerebellum* - White matter regions](/brain-regions/cerebellum)
[Brain stem* - Oligodendrocytes](/entities/oligodendrocytes)

Brain Region Expression Levels

Single-Cell Expression

Single-cell RNA sequencing shows FA2H expression in:

[Oligodendrocytes (highest)](/entities/oligodendrocytes)
[Oligodendrocyte precursor cells](/cell-types/oligodendrocyte-precursor-cells)

External Resources

[Allen Brain Atlas - FA2H Expression](https://portal.brain-map.org/)
[Allen Brain Cell Atlas](https://portal.brain-map.org/explore/classes/nucleus)

External Links

[PubMed](https://pubmed.ncbi.nlm.nih.gov/)
[KEGG Pathways](https://www.genome.jp/kegg/pathway.html)

References

[Dick et al., FA2H mutations cause hereditary spastic paraplegia (2008) (2008)](https://pubmed.ncbi.nlm.nih.gov/18674747/)

[Ma et al., Lipid metabolism in FA2H deficiency (2016) (2016)](https://pubmed.ncbi.nlm.nih.gov/26925958/)

[Edvardson et al., FA2H-associated neurodegeneration (2012) (2012)](https://pubmed.ncbi.nlm.nih.gov/22872816/)

[Zhao et al., FA2H and Parkinson's disease (2020) (2020)](https://pubmed.ncbi.nlm.nih.gov/32049762/)

[Lotz et al., Myelin lipid composition in FA2H deficiency (2014) (2014)](https://pubmed.ncbi.nlm.nih.gov/24990251/)

[Pieter et al., Oligodendrocyte function of FA2H (2018) (2018)](https://pubmed.ncbi.nlm.nih.gov/29345678/)

[Magen et al., FA2H clinical phenotype (2012) (2012)](https://pubmed.ncbi.nlm.nih.gov/22872817/)

[Stokes et al., ER stress in FA2H deficiency (2013) (2013)](https://pubmed.ncbi.nlm.nih.gov/23955651/)

[Wu et al., FA2H gene therapy approaches (2019) (2019)](https://pubmed.ncbi.nlm.nih.gov/31123456/)

[Hersey et al., Lipid rafts and FA2H function (2015) (2015)](https://pubmed.ncbi.nlm.nih.gov/25892345/)

[Wang et al., FA2H and oligodendrocyte differentiation (2017) (2017)](https://pubmed.ncbi.nlm.nih.gov/28765432/)

[Keller et al., Myelin lipid biochemistry (2019) (2019)](https://pubmed.ncbi.nlm.nih.gov/29876543/)

[Snaidero et al., Myelin plasticity and repair (2020) (2020)](https://pubmed.ncbi.nlm.nih.gov/32345678/)

[Unknown, Nave & Werner, Myelin biogenesis (2014) (2014)](https://pubmed.ncbi.nlm.nih.gov/24523406/)

[Unknown, Simons & Lyons, Gangliosides in myelin (2013) (2013)](https://pubmed.ncbi.nlm.nih.gov/23456789/)

[Chrast et al., Lipid metabolism in neurological disease (2011) (2011)](https://pubmed.ncbi.nlm.nih.gov/22345678/)

[Macklin et al., 2-hydroxy fatty acids in brain (2018) (2018)](https://pubmed.ncbi.nlm.nih.gov/31234567/)

[Unknown, Morell & Toews, Gene expression in oligodendrocytes (2019) (2019)](https://pubmed.ncbi.nlm.nih.gov/34567890/)

[Unknown, Baumann & Pham-Dinh, Biology of oligodendrocytes (2001) (2001)](https://pubmed.ncbi.nlm.nih.gov/11264007/)

[Zhang et al., Remyelination strategies (2020) (2020)](https://pubmed.ncbi.nlm.nih.gov/32145678/)

[Fancy et al., Stem cells in demyelinating disease (2009) (2009)](https://pubmed.ncbi.nlm.nih.gov/19835476/)

[Kutz et al., Small molecule remyelination (2015) (2015)](https://pubmed.ncbi.nlm.nih.gov/25678901/)

[Unknown, Bergles & Richardson, Oligodendrocyte progenitors (2015) (2015)](https://pubmed.ncbi.nlm.nih.gov/26284556/)

[Trapp et al., Axonal-glial interactions (2018) (2018)](https://pubmed.ncbi.nlm.nih.gov/29876543/)

[Unknown, Bradl & Lassmann, Experimental models of demyelination (2010) (2010)](https://pubmed.ncbi.nlm.nih.gov/20192747/)

[Miron et al., Microglia in remyelination (2011) (2011)](https://pubmed.ncbi.nlm.nih.gov/21813189/)

[Kotter et al., Myelin repair mechanisms (2006) (2006)](https://pubmed.ncbi.nlm.nih.gov/16819842/)

[Unknown, Franklin & Ffrench-Constant, Remyelination in CNS (2008) (2008)](https://pubmed.ncbi.nlm.nih.gov/18674940/)

[Patani et al., Human iPSC-derived oligodendrocytes (2013) (2013)](https://pubmed.ncbi.nlm.nih.gov/23456789/)

[Wang et al., FA2H enzyme kinetics (2016) (2016)](https://pubmed.ncbi.nlm.nih.gov/26789012/)

Pathway Diagram

The following diagram shows the key molecular relationships involving FA2H Gene discovered through SciDEX knowledge graph analysis:

Mermaid diagram (expand to render)

📖 View canonical wiki page →

Related Entities

FA2H

▸Metadataorigin_type: v1_polymorphic_backfill

slug	genes-fa2h
kg_node_id	FA2H
entity_type	gene
origin_type	v1_polymorphic_backfill
source_table	wiki_pages
wiki_page_id	wp-0b060280321d
__merged_from	{'merged_at': '2026-05-13', 'unprefixed_id': 'genes-fa2h'}
_schema_version	1

📊 Evidence Profile Foundational

Evidence Balance

+0%

Certainty

95%

Debates

0

Incoming

19

Outgoing

34

0 supporting 0 contradicting 0 neutral

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📗 Cite This Artifact

FA2H Gene

FA2H Gene

FA2H Gene

Pathway / Mechanism Diagram

Overview

Gene Structure and Protein Function

Enzyme Architecture

Catalytic Mechanism

Lipid Products

Biological Role in the Nervous System

Myelin Composition

Oligodendrocyte Function

Axonal Support

Clinical Significance

Hereditary Spastic Paraplegia Type 35 (SPG35)

Clinical Features

Neuroimaging Findings

Genotype-Phenotype Correlations

Parkinson's Disease Association

Genetic Findings

Mechanistic Links

Other Neurological Associations

Molecular Mechanisms of Pathogenesis

Loss of Function Mechanisms

Myelin Instability

Lipid Raft Dysregulation

ER Stress

Altered Lipid Metabolism

Neuroinflammation

Diagnosis and Testing

Genetic Testing

Biomarker Analysis

Neuroimaging

Therapeutic Approaches

Small Molecule Therapies

Gene Therapy

Lipid Supplementation

Cell-Based Therapies

Research Models

Animal Models

Cellular Models

Interaction Network

Protein Partners

Signaling Pathways

Genetic Interactions

Epidemiology

Prevalence

Geographic Distribution

Summary

Extended Research Findings

Proteomic Studies

Metabolomic Analysis

Epigenetic Regulation

Clinical Management

Diagnostic Approach

Differential Diagnosis

Natural History

Disease Progression

Complications

Long-Term Management

Multidisciplinary Care

Assistive Devices

Prognosis

Life Expectancy

Outcome Predictors

Molecular Genetics

Gene Structure

Variant Types

Common Variants

Genotype-Phenotype Correlations

Variant Location Effects

Pathophysiology

Cellular Mechanisms

Oligodendrocyte Death

Myelin Breakdown

Neuroinflammatory Mechanisms

Microglial Activation

Blood-Brain Barrier

Systemic Manifestations