rs28399499 CYP2B6
Normal CYP2B6 function at *18 position.
What is rs28399499?
rs28399499 is a single-nucleotide polymorphism (SNP) in the CYP2B6 gene (Cytochrome P450 2B6). Each person carries two copies, one from each parent, so a result is reported as a pair of letters such as TT. The table below describes what studies associate with each genotype; the association is statistical, across populations, and is not a diagnosis.
What does each rs28399499 genotype mean?
| Genotype | Association | What the evidence says | Confidence |
|---|---|---|---|
| TT | typical | Normal CYP2B6 function at *18 position. | 85% |
| TC | increased | CYP2B6 *18 carrier. No enzyme function from this allele. More common in African populations. | 85% |
| CC | increased | CYP2B6 *18 homozygous. No enzyme function. Significantly elevated efavirenz levels. | 85% |
Which drugs have annotations for rs28399499?
PharmGKB clinical annotations (level 1A is the strongest evidence, 4 the weakest):
| Drug | Annotation type | Evidence level |
|---|---|---|
| nevirapine | Toxicity, Metabolism/PK | 2A |
| efavirenz | Toxicity, Metabolism/PK | 2A |
Is rs28399499 on 23andMe and AncestryDNA chips?
Chip coverage is not recorded for this variant. Orviva reports it when a raw-data file contains it directly or via a well-correlated proxy SNP, and says so when it does not.
Sources
- PharmGKB:2A
- Drug:nevirapine
- Type:Toxicity
Upload your 23andMe, AncestryDNA or WeGene raw file → · Ask G2: “What is my genotype at rs28399499 and what does it mean for me?”
Genetic associations describe risk across populations, not a diagnosis for any one person. Most variants shift risk modestly and act alongside lifestyle, environment and other genes. Consumer DNA chips do not read every position and can be wrong at any single one. For general education only; talk to a clinician or genetic counsellor before acting on anything here, and never change a prescribed medicine without your prescriber.