GENE REFERENCE / HGNC:3513

EXT2

exostosin glycosyltransferase 2

protein-coding gene11p11.2Gene information

What does this gene do?

The EXT2 gene provides instructions for producing a protein called exostosin-2. This protein is found in a cell structure called the Golgi apparatus, which modifies newly produced enzymes and other proteins. In the Golgi apparatus, exostosin-2 binds to another protein, exostosin-1, to form a complex that modifies a protein called heparan sulfate.

Heparan sulfate is a complex of sugar molecules that is added to proteins. Heparan sulfate is involved in regulating a variety of body processes, including cell signaling, cell interactions, and immune system functions. Heparan sulfate is also involved in regulating bone formation (ossification) and the growth and specialization (differentiation) of cartilage-forming cells called chondrocytes. Cartilage is a tough, flexible tissue that makes up much of the skeleton during early development.

Source: MedlinePlus, National Library of Medicine. Source publication: 2026-04-07. Source review: 2026-04.

ClinGen reviews

ClinGen reviews the evidence linking a particular gene to a condition. Each rating below describes the strength of that link. It does not classify a variant in your DNA file.

Condition	Inheritance	Evidence
exostoses, multiple, type 2MONDO:0007586 · Evaluated 2018-12-21	Autosomal dominant	DefinitiveHereditary Cancer Gene Curation Expert Panel

ClinVar records

These numbers show what has been submitted to ClinVar. They cannot tell you how likely you are to have a condition.

Submitted alleles: 1,107
Submissions for variants in or overlapping this gene: 1,795
Submissions explicitly reporting this gene: 1,731
Alleles reported pathogenic / likely pathogenic: 264
VariationIDs with uncertain significance: 432
VariationIDs with conflicting classifications: 54

The rows count different things: alleles, submissions or VariationIDs. Their categories can overlap, so do not add them together. Pathogenic/likely pathogenic counts exclude structural variants that merely overlap a gene. A dash in the source means “not reported,” not zero.

NCBI produces the gene-summary file each week using counts recorded at the start of the month. The numbers may differ from those on the live ClinVar website. Read the field definitions ↗

View this gene in ClinVar ↗

YOUR DNA FILE

Can your DNA file tell you about EXT2?

From a DNA test kit (such as 23andMe, AncestryDNA or MyHeritage). These kits check a fixed list of about 600,000 to 700,000 positions across your whole genome. ClinVar lists 264 alleles in EXT2 reported as pathogenic or likely pathogenic. A kit checks only some of these positions, and often none of them.

From whole genome sequencing (a VCF file). Sequencing reads most of your genome. Your file lists the places where your DNA differs from the reference genome. Some regions are hard to sequence, including parts of some genes that have near-identical copies elsewhere, and a VCF file does not record which positions were read well.

If a variant is not in your file, that does not mean you don’t have it.

What BioDecode checks

BioDecode compares every variant in your file with ClinVar, on your own computer. For each match, it shows the ClinVar classification, the review status and the condition it was reported for. Your file is not uploaded.

A ClinVar classification applies to one particular variant and the condition it was reported for. It does not tell you about other variants in EXT2.

BioDecode cannot fill gaps in your test, diagnose a condition or replace clinical testing.

Buy BioDecode See a sample report →Check file compatibility →