BILIRUBIN, SERUM LEVEL OF, QUANTITATIVE TRAIT LOCUS 1: genes and variants
BILIRUBIN, SERUM LEVEL OF, QUANTITATIVE TRAIT LOCUS 1 is linked to 1 analyzed protein (UGT1A1). 2 DNA variants are known to cause it; 7 more are uncertain, and 0 of those already look disease-causing on computable evidence.
Last updated 2026-09-30. Research information, not medical advice.
Genes linked to BILIRUBIN, SERUM LEVEL OF, QUANTITATIVE TRAIT LOCUS 1
UGT1A1: UDP-glucuronosyltransferase 1A1
It conjugates bilirubin and many lipophilic compounds with glucuronic acid, enabling efficient elimination in bile or urine. Reduced activity causes Gilbert syndrome or Crigler-Najjar syndrome and can also increase toxicity from drugs such as irinotecan.
2 disease-causing and 7 uncertain variants in UGT1A1 are linked to BILIRUBIN, SERUM LEVEL OF, QUANTITATIVE TRAIT LOCUS 1.
Known disease-causing variants in BILIRUBIN, SERUM LEVEL OF, QUANTITATIVE TRAIT LOCUS 1
| Variant | Position | Protein part | Clinical label |
|---|---|---|---|
| UGT1A1 R209W | 209 | Disease-causing (★★) | |
| UGT1A1 P387R | 387 | Disease-causing (★★) |
Same protein, different disease
- Crigler-Najjar syndrome is also caused by UGT1A1 variants; they fall mostly in different places as the BILIRUBIN, SERUM LEVEL OF, QUANTITATIVE TRAIT LOCUS 1 variants (14 disease-causing).
- Gilbert syndrome is also caused by UGT1A1 variants; they fall mostly in different places as the BILIRUBIN, SERUM LEVEL OF, QUANTITATIVE TRAIT LOCUS 1 variants (10 disease-causing).
- Lucey-Driscoll syndrome is also caused by UGT1A1 variants; they fall mostly in different places as the BILIRUBIN, SERUM LEVEL OF, QUANTITATIVE TRAIT LOCUS 1 variants (4 disease-causing).
Diseases related to BILIRUBIN, SERUM LEVEL OF, QUANTITATIVE TRAIT LOCUS 1
- Crigler-Najjar syndrome, also linked to UGT1A1
- Gilbert syndrome, also linked to UGT1A1
- Lucey-Driscoll syndrome, also linked to UGT1A1
Frequently asked questions
Which genes are linked to BILIRUBIN, SERUM LEVEL OF, QUANTITATIVE TRAIT LOCUS 1?
In CATVariant, BILIRUBIN, SERUM LEVEL OF, QUANTITATIVE TRAIT LOCUS 1 is linked to 1 analyzed protein: UGT1A1 (UDP-glucuronosyltransferase 1A1).
How many genetic variants are linked to BILIRUBIN, SERUM LEVEL OF, QUANTITATIVE TRAIT LOCUS 1?
9 variants: 2 are classified as disease-causing (pathogenic or likely pathogenic) in ClinVar and 7 are of uncertain significance or have conflicting reports.
Which uncertain variants in BILIRUBIN, SERUM LEVEL OF, QUANTITATIVE TRAIT LOCUS 1 look disease-causing?
None of the uncertain variants currently reaches the likely-pathogenic range on computable evidence alone.
About this data
Variant–disease links come from ClinVar, Open Targets and UniProt, pooled from the latest public CATVariant analysis of each human protein. Evidence scores use the ACMG/AMP Bayesian points scale with computable criteria only (position among known disease variants, rarity in gnomAD, calibrated predictors, deep mutational scanning); there is no family or patient data, so they prioritise variants for expert review and never classify them.
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