UGT1A1
Chr 2ARADUDP glucuronosyltransferase family 1 member A1
Also known as: BILIQTL1, GNT1, HUG-BR1, UDPGT, UDPGT 1-1, UGT1, UGT1A
This gene encodes a UDP-glucuronosyltransferase, an enzyme of the glucuronidation pathway that transforms small lipophilic molecules, such as steroids, bilirubin, hormones, and drugs, into water-soluble, excretable metabolites. This gene is part of a complex locus that encodes several UDP-glucuronosyltransferases. The locus includes thirteen unique alternate first exons followed by four common exons. Four of the alternate first exons are considered pseudogenes. Each of the remaining nine 5' exons may be spliced to the four common exons, resulting in nine proteins with different N-termini and identical C-termini. Each first exon encodes the substrate binding site, and is regulated by its own promoter. The preferred substrate of this enzyme is bilirubin, although it also has moderate activity with simple phenols, flavones, and C18 steroids. Mutations in this gene result in Crigler-Najjar syndromes types I and II and in Gilbert syndrome. [provided by RefSeq, Jul 2008]
Primary Disease Associations & Inheritance
Clinical highlights
Population Genetics & Constraint
gnomAD v4 — loss-of-function & missense intolerance
Highly tolerant — LoF variants common in population
Tolerant to missense variation
ClinVar Variant Classifications
0 submitted variants in ClinVar
Protein Context — Lollipop Plot
UGT1A1 · protein map & ClinVar variants
Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.
External Resources
Links to major genomics databases and tools
Clinical Trials
Active and recruiting trials from ClinicalTrials.gov
GENOCARE: A Prospective, Randomized Clinical Trial of Genotype-Guided Dosing Versus Usual Care
RECRUITINGStudy of Sacituzumab Govitecan (SG) in Japanese Participants With Advanced Solid Tumors
ACTIVE NOT RECRUITINGAn Adaptive-design Prospective Cohort Study of Watch and Wait Strategy in Patients With Locally Advanced Rectal Cancer
NOT YET RECRUITINGSafety of Combining Irinotecan With 5-FU, Leucovorin/Folinic Acid, Oxaliplatin, and Docetaxel Chemotherapies
RECRUITINGUGT1A1-Based Irinotecan Therapy for Locally Advanced Rectal Cancer
RECRUITINGSacituzumab Govitecan Plus Bevacizumab in Metastatic TNBC
ENROLLING BY INVITATIONHypofractionated Radiotherapy Combined With NALIRIF, PD-1 Antibody in Locally Recurrent Rectal Cancer(NOVELTY-R)
RECRUITINGUGT1A1 Genotype-drien Phase I Study of Irinotecan in VIT Regimen for the Treatment of Pediatric R/R Solid Tumors
RECRUITINGGenetic Variants Associated With the Risk of Gall Stones and Cirrhosis.
NOT YET RECRUITINGThe Role of the Tumor Molecular Profile (CMS), UGT1A1 Genotype and Beta-glucuronidase Activity of the Intestinal Microbiota for Treatment Efficiency, Toxicity, Survival and Quality of Life in Patients With Metastatic or Unresectable Colorectal Cancer During Irinotecan-based Systemic Treatment
RECRUITINGClinical Study of Irinotecan Liposome Combination Therapy for Advanced Gastric Cancer
NOT YET RECRUITINGClinical Study of Irinotecan Liposome (II)-Based Combination Treatment for Irinotecan-resistant Colorectal Cancer.
RECRUITINGExternal Resources
Links to major genomics databases and tools