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Gene

EXT1

exostosin glycosyltransferase 1

Summary

Cytogenetic location
8q24.11
Coordinates
Chromosome 8: 117,794,490–118,111,826 (GRCh38)
Exons
11 exons across 317.3 kb
Protein
746 amino acids
Inheritance
Autosomal dominant
Also known as
ttv
Previous symbols
LGCR, LGS
MANE Select transcript
ENST00000378204.7NM_000127.3
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 report relevant to this gene

  • Hereditary Multiple Osteochondromas

    • Autosomal dominant

      A condition caused mainly by variants in EXT1 or EXT2 in which benign cartilage-capped bone growths develop at the ends of long bones.

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

      Knowing allows monitoring for growth problems and for the small lifetime risk (around 2 to 5%) that an osteochondroma becomes a chondrosarcoma.

Inheritance

Autosomal dominant
One changed copy, from either parent, is enough. A parent who has one passes it on to each child with a one-in-two chance.

How EXT1 is laid out

  • Coding sequence
  • Untranslated region
  • Intron
  • Direction of transcription
  • Known disease-causing sites
  • Stretches short reads find hard
Chromosome 8, with a bracket where EXT1 sits. EXT1 and 2 genes near it on chromosome 8, from 117,453,158 to 118,453,157.Chromosome 88q24.11p23.3p23.2p23.1p22p21.3p21.2p21.1p12p11.23p11.22p11.21p11.1q11.1q11.21q11.22q11.23q12.1q12.2q12.3q13.1q13.2q13.3q21.11q21.12q21.13q21.2q21.3q22.1q22.2q22.3q23.1q23.2q23.3q24.11q24.12q24.13q24.21q24.22q24.23q24.3117.6 Mb117.8 Mb118 Mb118.2 Mb118.4 MbMED30: 117,520,699–117,540,469, forward strandMED30EXT1: 117,794,490–118,111,826, reverse strandEXT1SAMD12: 118,189,455–118,622,112, reverse strandSAMD12Diagram of EXT1: 11 exons on the reverse strand of chromosome 8Exon 11: 11 known disease-causing sitesExon 10: 24 known disease-causing sitesExon 9: 31 known disease-causing sitesExon 8: 21 known disease-causing sitesExon 7: 9 known disease-causing sitesExon 6: 13 known disease-causing sitesExon 5: 20 known disease-causing sitesExon 4: 19 known disease-causing sitesExon 3: 16 known disease-causing sitesExon 2: 22 known disease-causing sitesExon 1: 168 known disease-causing sitesExon 11: 117,794,490–117,799,897, 5,408 basesExon 10: 117,804,722–117,804,893, 172 basesExon 9: 117,807,217–117,807,377, 161 basesExon 8: 117,812,872–117,812,961, 90 basesExon 7: 117,818,435–117,818,530, 96 basesExon 6: 117,819,676–117,819,794, 119 basesExon 5: 117,822,465–117,822,597, 133 basesExon 4: 117,830,230–117,830,349, 120 basesExon 3: 117,835,444–117,835,551, 108 basesExon 2: 117,837,108–117,837,201, 94 basesExon 1: 118,110,085–118,111,826, 1,742 bases1110864215′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 8.2 kb of the gene's 317.3 kb; 2,241 of those bases code for the protein.

How a genome test reads EXT1

397

positions in EXT1 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 317.3 kb of EXT1, introns included, not only the 8.2 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.). EXT1 gene: exostosin glycosyltransferase 1. Retrieved 17 October 2026, from https://dantelabs.com/genes/ext1

Vancouver

Dante Labs. EXT1 gene: exostosin glycosyltransferase 1 [Internet]. [cited 17 October 2026]. Available from: https://dantelabs.com/genes/ext1

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