GENE REFERENCE / HGNC:2577
CYBA
cytochrome b-245 alpha chain
What does this gene do?
The CYBA gene provides instructions for making a protein called the cytochrome b-245 alpha chain (also known as p22-phox). This protein is one part (subunit) of a group of proteins that forms an enzyme complex called NADPH oxidase, which plays an essential role in the immune system. Within this complex, the cytochrome b-245 alpha chain has a beta chain partner (produced from the CYBB gene). Both alpha and beta chains are required for either to function, and the NADPH oxidase complex requires both chains in order to be functional. NADPH oxidase is primarily active in immune system cells called phagocytes. These cells catch and destroy foreign invaders such as bacteria and fungi. NADPH oxidase is also thought to regulate the activity of immune cells called neutrophils. These cells play a role in adjusting the inflammatory response to optimize healing and reduce injury to the body.
The presence of foreign invaders stimulates phagocytes and triggers the assembly of NADPH oxidase. This enzyme participates in a chemical reaction that converts oxygen to a toxic molecule called superoxide. Superoxide is used to generate several other compounds, including hydrogen peroxide (a strong disinfectant) and hypochlorous acid (the active ingredient in bleach). These highly reactive, toxic substances are known as reactive oxygen species. Phagocytes use these substances to kill foreign invaders, preventing them from reproducing in the body and causing illness.
Related condition topics
MedlinePlus mentions this gene in the condition pages below. These links alone do not show that the gene causes a condition.
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
- 624
- Submissions for variants in or overlapping this gene
- 982
- Submissions explicitly reporting this gene
- 890
- Alleles reported pathogenic / likely pathogenic
- 98
- VariationIDs with uncertain significance
- 168
- VariationIDs with conflicting classifications
- 14
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 ↗
YOUR DNA FILE
Can your DNA file tell you about CYBA?
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 98 alleles in CYBA 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 CYBA.
BioDecode cannot fill gaps in your test, diagnose a condition or replace clinical testing.
Sources and dates
The source information on this page last changed on 2026-10-17.
HGNC Source details
Source release: Fri, 16 Oct 2026 13:36:12 GMT
Source record updated: 2023-06-30
SHA-256: 72bfe0c05800163c040a2cf663c70501f9ac9236469fbd0b552f2cd37a4d7f67
MedlinePlus Source details
Source release: Sat, 17 Oct 2026 05:15:49 GMT
Source publication: 2020-08-18
Source review: 2012-08
SHA-256: fdc8bd614310c12718379cef6569962e5d0e791cecabcc355b53a72816ac263a
ClinVar Source details
Source release: Sun, 11 Oct 2026 06:36:01 GMT
SHA-256: b21584f8ebc89a636ce9706023fa9052460587e2ab0fe6d0edf4b9db34336c02
About the library sources · Latest validated release · Record d9cef69319c2