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Gene

FMR1

fragile X messenger ribonucleoprotein 1

Summary

Cytogenetic location
Xq27.3
Coordinates
Chromosome X: 147,911,919–147,951,125 (GRCh38)
Exons
17 exons across 39.2 kb
Protein
632 amino acids
Inheritance
X-linked dominant
Also known as
FMRP, FRAXA, MGC87458
Previous symbols
POF1, POF
MANE Select transcript
ENST00000370475.9NM_002024.6
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

  • Female Infertility

    • Diminished or absent ability of a female to achieve conception.

      • 3 GenCC submitters rate it definitive or strong

  • Fragile X Syndrome

    • X-linked dominant

      An FMR1-related neurodevelopmental disorder caused by CGG-repeat expansion, with intellectual disability and behavioural features.

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

      Early intervention services, speech and occupational therapy, behavioral support, pharmacotherapy for anxiety and ADHD, preconception carrier screening, prenatal diagnosis, gene therapy in development

    • Fragile X-Associated Tremor/Ataxia Syndrome (FXTAS)

      A late-onset neurodegenerative condition in some carriers of an FMR1 premutation, with tremor, ataxia and cognitive decline, more often affecting men.

      • 3 GenCC submitters rate it definitive or strong

Inheritance

X-linked dominant
The change is on the X chromosome, and one copy is enough. A mother who has it passes it on to each child with a one-in-two chance; a father, to all of his daughters and none of his sons.

How FMR1 is laid out

  • Coding sequence
  • Untranslated region
  • Intron
  • Direction of transcription
  • Known disease-causing sites
  • Stretches short reads find hard
Chromosome X, with a bracket where FMR1 sits. FMR1 and 1 gene near it on chromosome X, from 147,431,522 to 148,431,521.Chromosome XXq27.3p22.33p22.32p22.31p22.2p22.13p22.12p22.11p21.3p21.2p21.1p11.4p11.3p11.23p11.22p11.21p11.1q11.1q11.2q12q13.1q13.2q13.3q21.1q21.2q21.31q21.32q21.33q22.1q22.2q22.3q23q24q25q26.1q26.2q26.3q27.1q27.2q27.3q28147.6 Mb147.8 Mb148 Mb148.2 Mb148.4 MbFMR1: 147,911,919–147,951,125, forward strandFMR1FMR1NB: 147,981,235–148,026,665, forward strandFMR1NBDiagram of FMR1: 17 exons on the forward strand of chromosome XExon 4: 1 known disease-causing siteExon 6: 1 known disease-causing siteExon 12: 1 known disease-causing siteExon 13: 1 known disease-causing siteExon 14: 2 known disease-causing sitesExon 1: 147,911,919–147,912,230, 312 basesExon 2: 147,921,933–147,921,985, 53 basesExon 3: 147,925,540–147,925,633, 94 basesExon 4: 147,928,322–147,928,393, 72 basesExon 5: 147,928,659–147,928,807, 149 basesExon 6: 147,929,948–147,930,041, 94 basesExon 7: 147,930,128–147,930,244, 117 basesExon 8: 147,932,425–147,932,595, 171 basesExon 9: 147,932,685–147,932,763, 79 basesExon 10: 147,936,504–147,936,613, 110 basesExon 11: 147,937,466–147,937,600, 135 basesExon 12: 147,938,099–147,938,161, 63 basesExon 13: 147,940,576–147,940,662, 87 basesExon 14: 147,943,131–147,943,326, 196 basesExon 15: 147,944,869–147,945,051, 183 basesExon 16: 147,945,534–147,945,616, 83 basesExon 17: 147,948,683–147,951,125, 2,443 bases1246810121416175′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 4.4 kb of the gene's 39.2 kb; 1,899 of those bases code for the protein.

How a genome test reads FMR1

7

positions in FMR1 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 39.2 kb of FMR1, introns included, not only the 4.4 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.). FMR1 gene: fragile X messenger ribonucleoprotein 1. Retrieved 17 October 2026, from https://dantelabs.com/genes/fmr1

Vancouver

Dante Labs. FMR1 gene: fragile X messenger ribonucleoprotein 1 [Internet]. [cited 17 October 2026]. Available from: https://dantelabs.com/genes/fmr1

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