FXN (Frataxin) Gene
Mitochondrial Iron Chaperone and Friedreich Ataxia Gene
Gene Information Card
| Symbol | FXN |
|---|---|
| Full Name | Frataxin |
| Gene Type | Protein coding |
| Chromosomal Location | 9q21.11 |
| NCBI Gene ID | 2395 ncbi.nlm.nih.gov/gene/2395 |
| Ensembl ID | ENSG00000165060 |
| UniProt ID | Q16595 |
| OMIM ID | 606829 |
| HGNC ID | 3951 |
| Aliases | FRDA, X25, FARR, CyaY |
Description
The FXN gene encodes frataxin, a mitochondrial protein involved in iron-sulfur cluster biogenesis and iron homeostasis. Loss of frataxin leads to mitochondrial iron accumulation, oxidative stress, and neurodegeneration characteristic of Friedreich ataxia.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Friedreich Ataxia | Intronic GAA repeat expansion reduces frataxin expression, impairing iron-sulfur cluster assembly and causing mitochondrial dysfunction. | ClinVar, OMIM |
| Spinocerebellar Ataxia (rare) | Missense mutations in FXN may disrupt frataxin folding and iron binding. | ClinVar |
| Cardiomyopathy (associated) | Frataxin deficiency in cardiac muscle leads to iron overload and oxidative damage. | OMIM |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Heart | 12.3 | Medium |
| Cerebellum | 9.8 | Medium |
| Spinal Cord | 7.5 | Low |
| Liver | 6.2 | Low |
| Skeletal Muscle | 5.1 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HeLa | 8.4 | Fibroblast-like expression |
| SH-SY5Y | 6.7 | Neuronal model |
| HepG2 | 5.9 | Hepatocyte expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| GAA repeat expansion (intron 1) | Repeat expansion | ~96% of alleles | Reduced frataxin transcription |
| p.Ile154Phe | Missense | <1% | Impaired iron binding |
| p.Gly130Val | Missense | <1% | Protein instability |
| c.1A>G | Start loss | Rare | Loss of translation initiation |
Mutation functional classification
Loss of Function (LOF)
GAA repeat expansions and missense mutations reduce frataxin protein levels or activity, leading to iron-sulfur cluster deficiency.
Gain of Function (GOF)
None reported.
Dominant Negative (DN)
Not applicable; Friedreich ataxia is autosomal recessive.
View complete mutation data：
Gene Ontology (GO)
| • mitochondrion (GO:0005739) | • cellular iron ion homeostasis (GO:0006879) |
| • iron-sulfur cluster assembly (GO:0016226) | • 2 iron, 2 sulfur cluster binding (GO:0051537) |
| • iron ion binding (GO:0005506) |
Pathways
• Iron-sulfur cluster biogenesis (Reactome R-HSA-1369007)
• Mitochondrial iron homeostasis (KEGG hsa04217)
Protein Summary
Frataxin is a small mitochondrial protein (210 amino acids) that acts as an iron chaperone for iron-sulfur cluster assembly. It is highly conserved from bacteria to humans. Deficiency leads to mitochondrial iron accumulation, oxidative stress, and selective degeneration of sensory neurons and cardiomyocytes.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| FXN Knockout HEK293 Cell Line | EDJ-KQ50282 | Human | 2395 | Details Get a Quote |
| FXN Knockout HeLa Cell Line | EDJ-KQ53266 | Human | 2395 | Details Get a Quote |
| FXN Knockout A-549 Cell Line | EDJ-KQ61749 | Human | 2395 | Details Get a Quote |
| FXN Knockout HCT 116 Cell Line | EDJ-KQ70234 | Human | 2395 | Details Get a Quote |
