GENE REFERENCE / HGNC:4235

GFAP

glial fibrillary acidic protein

protein-coding gene17q21.31Gene information

What does this gene do?

The GFAP gene provides instructions for making a protein called glial fibrillary acidic protein. This protein is a member of the intermediate filament family of proteins. Intermediate filaments form networks that provide support and strength to cells. Several molecules of glial fibrillary acidic protein bind together to form the type of intermediate filament found in astroglial cells. Astroglial cells support and nourish cells in the brain and spinal cord. If brain or spinal cord cells are injured through trauma or disease, astroglial cells react by rapidly producing more glial fibrillary acidic protein.

Although its function is not fully understood, glial fibrillary acidic protein is probably involved in controlling the shape, movement, and function of astroglial cells. Some researchers have suggested that astroglial cells play an important role in the functioning of other cells, including specialized cells that surround nerves (oligodendrocytes) and are involved in the production and long-term maintenance of myelin. Myelin is the fatty substance that forms a protective coating around certain nerve cells and ensures the rapid transmission of nerve impulses. Additionally, astroglial cells may assist in maintaining the protective barrier that allows only certain substances to pass between blood vessels and the brain (the blood-brain barrier).

Source: MedlinePlus, National Library of Medicine. Source publication: 2020-08-18. Source review: 2008-11.

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
Alexander diseaseMONDO:0008752 · Evaluated 2024-01-10	Autosomal dominant	DefinitiveLeukodystrophy and Leukoencephalopathy 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: 666
Submissions for variants in or overlapping this gene: 1,229
Submissions explicitly reporting this gene: 1,152
Alleles reported pathogenic / likely pathogenic: 84
VariationIDs with uncertain significance: 274
VariationIDs with conflicting classifications: 35

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 GFAP?

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 84 alleles in GFAP 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 GFAP.

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

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