<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
<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>
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]
FA2H is a member of the fatty acid hydroxylase family characterized by: [@snaidero2020]
The 2-hydroxylation reaction proceeds through: [@nave2014]
FA2H produces 2-hydroxy fatty acids that are incorporated into: [@simons2013]
The myelin sheath contains exceptionally high concentrations of 2-hydroxy fatty acids: [@kutz2015]
FA2H is highly expressed in oligodendrocyte precursor cells (OPCs) and maturing oligodendrocytes: [@bergles2015]
Beyond myelin formation, FA2H supports axonal health through: [@trapp2018]
Biallelic pathogenic variants in FA2H cause autosomal recessive SPG35: [@bradl2010]
Emerging evidence links FA2H to Parkinson's disease:
FA2H deficiency leads to neurodegeneration through:
Pathogenic variants disrupt lipid homeostasis:
FA2H deficiency triggers inflammatory responses:
Molecular diagnosis involves:
Diagnostic imaging findings:
Current pharmacological strategies:
Emerging therapeutic modalities:
Dietary approaches under investigation:
FA2H interacts with key proteins:
FA2H influences multiple pathways:
Modifying genes in FA2H-related disease:
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.
Recent proteomic analyses of FA2H-deficient models reveal:
Metabolomic profiling shows:
FA2H expression is regulated by:
FA2H-related disorders must be differentiated from other causes of spasticity and white matter disease:
The clinical course of FA2H-related HSP follows predictable stages:
FA2H gene organization:
FA2H deficiency leads to oligodendrocyte apoptosis:
Activated microglia release:
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.
Current management includes:
Emerging treatments under investigation:
Fa2h knockout mice exhibit:
FA2H as a therapeutic target:
FA2H disorders are autosomal recessive:
Options for affected families:
The following diagram shows the key molecular relationships involving FA2H Gene discovered through SciDEX knowledge graph analysis: