GENE REFERENCE / HGNC:2216

COL8A2

collagen type VIII alpha 2 chain

protein-coding gene1p34.3Gene information

What does this gene do?

The COL8A2 gene provides instructions for making a component of type VIII collagen called alpha 2(VIII) collagen. Type VIII collagen is largely found within the front surface of the eye, called the cornea. Type VIII collagen is a major component of Descemet's membrane, which is a tissue at the back of the cornea. This membrane is a thin, sheet-like structure that separates and supports corneal endothelium cells. These cells regulate the amount of fluid inside the cornea. An appropriate fluid balance in the cornea is necessary for clear vision.

To construct type VIII collagen, one subunit of the alpha 2(VIII) collagen protein interacts with two subunits of another protein called alpha 1(VIII) collagen. These three proteins twist together to form a triple-stranded, rope-like molecule known as procollagen. Procollagen molecules are secreted by the cell and processed by enzymes to remove extra protein segments from the ends. Once these molecules are processed, they arrange themselves into long, thin bundles of mature type VIII collagen.

Source: MedlinePlus, National Library of Medicine. Source publication: 2020-08-18. Source review: 2011-06.

ClinGen reviews

We found no matching ClinGen review in the data used here. This does not rule out a link between the gene and a condition.

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: 222
Submissions for variants in or overlapping this gene: 290
Submissions explicitly reporting this gene: 267
Alleles reported pathogenic / likely pathogenic: 3
VariationIDs with uncertain significance: 137
VariationIDs with conflicting classifications: 1

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 COL8A2?

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 3 alleles in COL8A2 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 COL8A2.

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

Buy BioDecode See a sample report →Check file compatibility →