rs4148323 UGT1A1
Homozygous risk allele (A). Associated with: BILIRUBIN, SERUM LEVEL OF, QUANTITATIVE TRAIT LOCUS 1; phenotype not specified; CRIGLER-NAJJAR SYNDROME, TYPE II
What is rs4148323?
rs4148323 is a single-nucleotide polymorphism (SNP) in the UGT1A1 gene (UDP glucuronosyltransferase 1A1). Each person carries two copies, one from each parent, so a result is reported as a pair of letters such as AA. The table below describes what studies associate with each genotype; the association is statistical, across populations, and is not a diagnosis.
What does each rs4148323 genotype mean?
| Genotype | Association | What the evidence says | Confidence |
|---|---|---|---|
| AA | elevated | Homozygous risk allele (A). Associated with: BILIRUBIN, SERUM LEVEL OF, QUANTITATIVE TRAIT LOCUS 1; phenotype not specified; CRIGLER-NAJJAR SYNDROME, TYPE II | 65% |
| GG | typical | Normal UGT1A1 function at this position. Standard irinotecan dosing. | 90% |
| GA | increased | UGT1A1 *6 carrier. Decreased glucuronidation. Increased risk of irinotecan toxicity, especially in East Asian populations. | 90% |
Which drugs have annotations for rs4148323?
PharmGKB clinical annotations (level 1A is the strongest evidence, 4 the weakest):
| Drug | Annotation type | Evidence level |
|---|---|---|
| indinavir | Toxicity, Other, Metabolism/PK, Efficacy, Dosage | 3 |
| carvedilol | Toxicity, Other, Metabolism/PK, Efficacy, Dosage | 3 |
Is rs4148323 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:3
- Drug:indinavir
- Type:Toxicity
Upload your 23andMe, AncestryDNA or WeGene raw file → · Ask G2: “What is my genotype at rs4148323 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.