Skip to content
Use your HSA or FSA funds

Gene

FXN

frataxin

Summary

Cytogenetic location
9q21.11
Coordinates
Chromosome 9: 69,035,752–69,079,076 (GRCh38)
Exons
5 exons across 43.3 kb
Protein
210 amino acids
Inheritance
Autosomal recessive
Also known as
FA, FARR, X25, CyaY
Previous symbols
FRDA
MANE Select transcript
ENST00000484259.3NM_000144.5
Locus type
gene with protein product
  • Very high
  • Confident
  • Low
  • Very low

Reference genomeGRCh38

Positions on gene and variant pages follow this choice, in this browser.

Curated reports relevant to this gene

  • Friedreich Ataxia

    • Autosomal recessive

      A progressive ataxia caused by biallelic FXN variants, most often an expanded GAA repeat in intron 1, with sensory neuropathy, cardiomyopathy and an increased risk of diabetes.

      • ClinGen rates the link definitive
      • 4 GenCC submitters rate it definitive or strong
      What knowing changes

      Regular neurological, cardiac and diabetes monitoring; omaveloxolone is approved for people aged 16 and over in the US and EU; carrier testing for relatives and reproductive counselling.

Broader groupings

  • Autosomal Recessive Cerebellar Ataxias (incl. CANVAS and AVED)

    • Autosomal Recessive Cerebellar AtaxiaAutosomal recessive

      One of 57 genes linked to it

      A group of recessively inherited ataxias caused by biallelic variants in genes such as RFC1, FXN, SACS, TTPA, SETX, APTX, PNKP, ANO10 and SYNE1.

      • ClinGen rates the link definitive
      • 4 GenCC submitters rate it definitive or strong
      What knowing changes

      Ataxia with vitamin E deficiency (TTPA) is treatable with vitamin E supplements; other forms are managed with physiotherapy and symptom care, and relatives can be offered carrier testing.

Inheritance

Autosomal recessive
It takes a changed copy from each parent. With one, you are a carrier and usually unaffected; when both parents are carriers, each child has a one-in-four chance of inheriting two.

How FXN is laid out

  • Coding sequence
  • Untranslated region
  • Intron
  • Direction of transcription
  • Known disease-causing sites
  • Stretches short reads find hard
Chromosome 9, with a bracket where FXN sits. FXN and 7 genes near it on chromosome 9, from 68,557,414 to 69,557,413.Chromosome 99q21.11p24.3p24.2p24.1p23p22.3p22.2p22.1p21.3p21.2p21.1p13.3p13.2p13.1p12p11.2p11.1q11q12q13q21.11q21.12q21.13q21.2q21.31q21.32q21.33q22.1q22.2q22.31q22.32q22.33q31.1q31.2q31.3q32q33.1q33.2q33.3q34.11q34.12q34.13q34.2q34.368.6 Mb68.8 Mb69 Mb69.2 Mb69.4 MbPIP5K1B: 68,705,185–69,009,191, forward strandPIP5K1BPABIR1: 68,780,065–68,785,566, forward strandPABIR1PRKACG: 69,012,504–69,014,113, reverse strandPRKACG: 69,035,747–69,255,187, forward strandFXN: 69,035,752–69,079,076, forward strandFXNTJP2: 69,121,264–69,274,641, forward strandTJP2ENTREP1: 69,324,567–69,392,620, forward strandENTREP1APBA1: 69,427,532–69,672,392, reverse strandAPBA1Diagram of FXN: 5 exons on the forward strand of chromosome 9Exon 1: 2 known disease-causing sitesExon 2: 1 known disease-causing siteExon 3: 1 known disease-causing siteExon 4: 3 known disease-causing sitesExon 1: 69,035,752–69,035,947, 196 basesExon 2: 69,046,385–69,046,482, 98 basesExon 3: 69,053,140–69,053,260, 121 basesExon 4: 69,064,938–69,065,035, 98 basesExon 5: 69,072,612–69,079,076, 6,465 bases123455′3′

Exons of the gene's MANE Select transcript (release v1.5), from NCBI and EMBL-EBI, on the GRCh38 reference genome.

Chromosome bands from UCSC's GRCh38 ideogram (2022-10-29).

Nearby genes from Ensembl release 116, on GRCh38.

Exons make up 7 kb of the gene's 43.3 kb; 633 of those bases code for the protein.

How a genome test reads FXN

11

positions in FXN where ClinVar classes a change as pathogenic or likely pathogenic

None of them falls in a region short reads find hard.

A whole genome covers all 43.3 kb of FXN, introns included, not only the 7 kb of exons.

Where this comes from

  • HGNC: the gene's symbol, name, other symbols and location.
  • MANE Select v1.5, from NCBI and EMBL-EBI: the transcript, its exons and coding sequence.
  • GenCC and ClinGen, released 2026-10-16: which conditions the gene is linked to, and how strongly.
  • The ACMG secondary findings list, SF v3.2.
  • ClinVar and the GIAB stratifications: known disease-causing sites, and the regions short reads find hard.
  • The Human Phenotype Ontology, release 2026-09-01: the traits linked to the gene. Find out more at hpo.jax.org.
  • Data release 2026.10.16-c6eea6bf.

Cite this page

APA

Dante Labs. (n.d.). FXN gene: frataxin. Retrieved 16 October 2026, from https://dantelabs.com/genes/fxn

Vancouver

Dante Labs. FXN gene: frataxin [Internet]. [cited 16 October 2026]. Available from: https://dantelabs.com/genes/fxn

One test. A lifetime of answers.

From $449Free shipping · Results in 6–8 weeks

Get my Genome Test