Novel nomogram for differential diagnosis of UGT1A1 gene mutation-associated unconjugated hyperbilirubinemia with hemolytic diseases

The uridine diphosphate-glucuronosyl transferase 1A1 (UGT1A1) gene mutation can affect the expression of UGT1A1 gene and enzyme activity, and then reduce bilirubin metabolism leading to unconjugated hyperbi-lirubinemia.With the development of molecular biotechnology, more and more studies are trying to identify the pathogenesis of these polymorphisms by analyzing the expression and enzyme activity of UGT1A1 gene polymorphisms.Now, the progresses in the study of the expression of UGT1A1 gene polymorphism were reviewed. Key words: Uridine diphosphate-glucuronosyl transferase 1A1 gene; Polymorphism; Unconjugated hyperbi-lirubinemia; Enzyme activity

With dense single-nucleotide polymorphism (SNP) maps for 199 drug-related genes, we examined associations between 4190 SNPs and 38 commonly measured quantitative traits using data from 752 healthy Japanese subjects. On analysis, we observed a strong association between five SNPs within the uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1) gene and serum total bilirubin levels (minimum P-value in Mann-Whitney test=1.82 x 10(10)). UGT1A1 catalyzes the conjugation of bilirubin with glucuronic acid, thus enhancing bilirubin elimination. This enzyme is known to play an important role in the variation of serum bilirubin levels. The five SNPs, including a nonsynonymous SNP-rs4148323 (211G>A or G71R variant allele known as UGT1A1*6)-showed strong linkage disequilibrium with each other. No other genes were clearly associated with serum total bilirubin levels. Results of linear multiple regression analysis on serum total bilirubin levels followed by analysis of variance showed that at least 13% of the variance in serum total bilirubin levels could be explained by three haplotype-tagging SNPs in the UGT1A1 gene.

Objective: Uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1) is a key enzyme in irinotecan metabolism. However, the relationship between UGT1A1 genotype and the safety and efficacy of irinotecan monotherapy in the treatment of Chinese advanced gastric cancer remains unclear. Methods: A total of 110 patients were enrolled. Intravenous irinotecan was administered every 3 weeks. Irinotecan dose was selected according to the polymorphism of UGT1A1 gene, which was divided into 3 groups: UGT1A1*6 wild-type (GG type): 125mg/m2, d1, d8; UGT1A1*6 mutant heterozygosity (GA type) 100mg/m2, d1, d8; UGT1A1*6 homozygosity mutation (AA type) 75mg/m2, d1, d8 or paclitaxel 125mg/m2, d1, d8. UGT1A1 genotypes were determined by direct sequencing or next-generation sequencing of genomic DNA extracted from peripheral blood. Results: Among 110 patients of the subjects, the genotypes of UGT1A1*28 were wild-type in 78 patients (70.91%), mutant heterozygosity in 28 (25.45%) and mutant homozygosity in 4 (3.64%). UGT1A1*6 were GG in 67 cases (60.91%), GA in 35 cases (31.82%), and AA in 8 cases (7.27%). There were two heterozygous mutations in 3 patients, and no homozygous mutation was detected. A total of 10 cycles of irinotecan were administered, with a median of five cycles per patient. There was no significant difference in the risk of delayed diarrhea and granulocytopenia in patients with different UGT1A1*28 genotypes (P>0.05), while there was significant difference in the risk of delayed diarrhea and granulocytopenia in patients with different UGT1A1*6 genotypes (P<0.05). The dose intensity of irinotecan was different in patients with different subtypes of UGT1A1*6 gene, and the dose intensity of heterozygous mutant patients was lower than that of wild-type patients. However, there were no significant differences in PFS and OS among patients with different subtypes after dose adjustment and program adjustment (P>0.05). Conclusion: UGT1A1*6 gene polymorphism was significantly associated with diarrhea and neutropenia induced by irinotecan. The safety and effectiveness of antitumor therapy might be significantly improved by individualized drug administration according to the results of UGT1A1*6 gene polymorphism. Citation Format: Huifang Lv, Yunduan He, Caiyun Nie, Beibei Chen, Jianzheng Wang, Weifeng Xu, Jing Zhao, Xiaobing Chen, Junling Zhang. Association between UGT1A1 gene polymorphism and safety and efficacy of irinotecan monotherapy as the second-line treatment for advanced gastric cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5250.

Uridine diphosphate glucuronosyl transferase 1A1 (UGT1A1) is a key conjugating enzyme of bilirubin and the anti-tumor medication irinotecan. Comprehensive analysis of UGT1A1 gene polymorphisms may provide benefit by predicting pharmacokinetics and outcomes of treatment with irinotecan and certain antiviral medications. A high-resolution melting (HRM) analysis was designed to characterize the UGT1A1 gene. Genomic DNA from 110 healthy subjects was extracted from peripheral blood samples. The promoter and 11 exons from UGT1A1 were screened by HRM, and all results were subsequently confirmed by direct DNA sequencing. HRM analysis readily identified UGT1A1 gene mutations. We identified 5 different known variants of UGT1A1 including c.211 G > A; G71R, c.686 C > A; P229Q, c.1091 C > T; c.-3279 T > G; and c.-3156 G > A in 110 normal Taiwanese individuals. We also identified 8 new sequence variants, namely, c.-3296 C > T; c.43 C > A; c.45 G > A; c.234 G > A; c.577 G > A; c.614 C > T; c.1011 T > C; and c.1352 C > T. Each UGT1A1 variant was easily identifiable by differences in curves plotted from HRM data. HRM analysis was rapid, accurate, and economical for screening UGT1A1 gene mutations.

Irinotecan is a key chemotherapeutic drug used to treat many tumors, including cervical and ovarian cancers; however, irinotecan can cause toxicity, particularly in the presence of uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1) gene polymorphisms, which are associated with reduced enzyme activity. Here, we investigated the prevalence of three different variants of UGT1A1 (UGT1A1*6, UGT1A1*27 and UGT1A1*28) and their relationships with irinotecan-induced adverse events in patients with gynecologic cancer, who are treated with lower doses of irinotecan than patients with other types of solid tumors. Fifty-three female patients treated with irinotecan and 362 female patients not treated with irinotecan were screened for UGT1A1*6, UGT1A1*27 and UGT1A1*28. Homozygosity for UGT1A1*6 or heterozygosity for UGT1A1*6/*28 was associated with a high risk of severe absolute neutrophil count decrease or diarrhea (odds ratios: 16.03 and 31.33, respectively). In contrast, serum bilirubin levels were not associated with irinotecan toxicity. Homozygosity for UGT1A1*6/*6 and heterozygosity for UGT1A1*6/*28 were associated with an increased risk of absolute neutrophil count and/or diarrhea in Japanese gynecologic cancer patients, despite the lower doses of irinotecan used in these patients. UGT1A1*6 and UGT1A1*28 are potential predictors of severe absolute neutrophil decrease and diarrhea caused by low-dose irinotecan in gynecologic cancer patients.

Background: Gilbert syndrome is caused by defects in the uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1) gene. These mutations differ among different populations and many of them have been found to be genetic risk factors for the development of neonatal jaundice. Objectives: The objective was to determine the frequencies of the following mutations in the UGT1A1 gene: A(TA)₇TAA (the most common cause of Gilbert syndrome in Caucasians), G71R (more common in the Japanese and Taiwanese population), and G493R (described in a homozygous Malay woman with Crigler-Najjar syndrome type 2) in a group of Malaysian babies with hyperbilirubinemia and a group of normal controls. Methods: The GeneScan fragment analysis was used to detect the A(TA)₇TAA variant. Mutation screening of both G71R and G493R was performed using denaturing high performance liquid chromatography. Results: Fourteen out of fifty-five neonates with hyperbilirubinemia (25%) carried the A(TA)₇TAA mutation (10 heterozygous, 4 homozygous). Seven out of fifty controls (14%) carried this mutation (6 heterozygous, 1 homozygous). The allelic frequencies for hyperbilirubinemia and control patients were 16 and 8%, respectively (p = 0.20). Heterozygosity for the G71R mutation was almost equal among both groups (5.5% for hyperbilirubinemia patients and 6.0% for controls; p = 0.61). One subject (1.8%) in the hyperbilirubinemia group and none of the controls were heterozygous for the G493R mutation (p = 0.476). Conclusions: The A(TA)₇TAA seems more common than the G71R and G493R mutations in the Malaysian population.

Background: Single nucleotide polymorphism (SNP) variants of the uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1) gene have been studied as an important factor in neonatal hyperbilirubinemia (jaundice) severity. Specific ethnicities, including Asians, have certain SNPs that appear more frequently than others.Aim: To identify the most common SNPs in Indonesian neonates and their association with the severity of neonatal hyperbilirubinemia.Methods: Eighty-eight inborn and outborn jaundiced infants from three different hospitals (Bengkulu, Jakarta, Biak Papua) across Indonesia were enrolled in this cross-sectional study and their peak total serum bilirubin (TSB) levels assessed. SNP variant analyses of the TATAA box, promoter, and exon 1 regions of UGT1A1 gene from 78 of the 88 infants were carried out using the SNaPshotR Multiplex Polymerase Chain Reaction (PCR) System followed by DNA sequencing.Results: We detected SNP variants UGT1A1*28, UGT1A1*60, UGT1A1*93, and UGT1A1*6 in our population. Mean total serum bilirubin (TSB) was 14.59 ± 5.57 mg/dL. Bivariate analyses using delivery location, gestational age, birth weight, mother's age, and ethnicity were shown to be associated with moderate-to-severe hyperbilirubinemia (p < 0.05). None of the four SNPs appeared to be associated with moderate-to-severe hyperbilirubinemia. In multivariate analysis, however, only the “other ethnic group” (e.g., Chinese, Bengkulu, Papua, Bima) category showed an association with moderate-to-severe hyperbilirubinemia, with an odds ratio of 6.49 (95% CI 1.01–41.67; p < 0.05).Conclusions: We found that the UGT1A1*60 is the most common SNP detected in neonates with hyperbilirubinemia in the Indonesian population. Interestingly, in Indonesia, UGT1A1 polymorphisms do not appear to be associated with differences in the severity of hyperbilirubinemia.

The variation rate within the coding region of UDP-glucuronosyl transferase 1A1 (UGT1A1) gene in Taiwan Chinese was found to be 29.3%. This study sought to determine whether that high variation rate of UGT1A1 gene is a risk factor for neonatal hyperbilirubinemia. The study subjects consisted of 123 newborn infants suffering from unconjugated hyperbilirubinemia who had no known risk factors for hyperbilirubinemia and 218 healthy control neonates. The promoter area, exons 1 to 4, coding region of exon 5, and the flanking intronic regions in UGT1A1 gene were determined by the PCR in all subjects. Wild UGT1A1 gene, variation in the promoter, variation at nucleotide 211, variation at nucleotide 1091, and compound heterozygous variation of UGT1A1 gene were found. The percentage of neonates with wild UGT1A1 gene and the percentage of neonates with variation at nucleotide 211 were significantly different between the study subjects and controls. The percentages with bilirubin >or=342 micro M (20.0 mg/dL) and with persistent hyperbilirubinemia in the subjects carrying homozygous variation at nucleotide 211 (Gly71Arg) were significantly higher than the neonates carrying wild type or other genotypes. In conclusion, this study has demonstrated that variation at nucleotide 211 of the UGT1A1 gene is a risk factor for the development of neonatal hyperbilirubinemia. Pediatricians should closely follow hyperbilirubinemic newborn infants who carry homozygous 211 G to A variation in UGT1A1 gene.

To investigate the distribution of uridine diphosphate-glucuronosyltransferase 1A1 (UGT1A1) gene promoter polymorphism and its relation to the toxicities caused by irinotecan in Chinese patients with cervical cancer and ovarian cancer. Sixty-four blood samples were taken from the patients with ovarian cancer and cervical cancer. The DNA was extracted and amplified with PCR. Then, the sequences of UGT1A1 gene promoter were detected by capillary electrophoresis allele fragment analysis (size-based analysis) methods. The relationship between UGT1A1 gene promoter polymorphism and the toxicity caused by irinotecan was analyzed. In all the patients, TA 6/6 was the most common genotype of UGT1A1 gene promoter (44 cases), accounting for 69% (44/64), followed by genotype of TA 6/7 (17 cases, 27%, 17/64), while genotype TA 7/7 was rare (3 cases, 5%, 3/64). The genotypes of UGT1A1 gene promoter was an independent factor for the occurrence of delayed diarrhea (P = 0.040, OR = 4.228, 95%CI: 1.065 - 16.785) but not for neutropenia (P = 0.068, OR = 3.659, 95%CI: 0.911 - 14.700). The patients with both genotype TA 6/7 and TA 7/7 presented much higher risk of delayed diarrhea and neutropenia than those with TA 6/6 (all P = 0.001). UGT1A1 gene promoter polymorphism may be a significant influencing factor for delayed diarrhea. The patients with both genotype TA 6/7 and TA 7/7 could present much higher risk for delayed diarrhea than those with TA 6/6, while genotype TA 6/6 may be the most common UGT1A1 promoter type in Chinese patients with cervical or ovarian cancer.

Distinct Associations Between UGT1A1 Gene Promoter Polymorphism and Hyperbilirubinemia in Korean CML Patients Treated with Nilotinib and Radotinib

Breastfeeding jaundice is a common problem in neonates who were exclusively breastfed, but its pathogenesis is still unclear. The uridine diphosphate glucuronosyl transferase 1A1 (UGT1A1) gene polymorphism was shown to contribute to the development of neonatal hyperbilirubinemia. We hypothesize that the variation of UGT1A1 gene may contribute to neonatal breastfeeding jaundice. We prospectively enrolled 688 near-term and term infants who were exclusively breastfed (BF group) or were supplemented by infant formula partially (SF group) before onset of hyperbilirubinemia. Genotyping of the promoter and exon1 of UGT1A1 was performed in all neonates. Neonates in BF group had a significantly higher maximal body weight loss ratio, peak bilirubin level, and a greater incidence of hyperbilirubinemia than those in SF group. Neonates with nucleotide 211 GA or AA variation in UGT1A1 genotypes had higher peak serum bilirubin levels and higher incidence of hyperbilirubinemia than WTs (GG). This phenomenon was only seen in BF group but not in SF group when subset analysis was performed. This suggests that neonates who carry the nucleotide 211 GA or AA variation within coding region in UGT1A1 gene are more susceptible to develop early-onset neonatal breastfeeding jaundice.

UDP-glucuronosyltransferase 1A1 (UGT1A1) is the key enzyme for bilirubin conjugation. Defects in this enzyme can cause a nonhemolytic unconjugated hyperbilirubinemia, such as Crigler–Najjar syndrome type 1 (CN1) and 2 (CN2) and Gilbert syndrome (GS). In 1991, the cDNA of the human UGT1A1 gene was cloned, and this led to the identification of genetic defects in patients with CN1, CN2, and GS (1)(2)(3). It was shown that homozygous or compound heterozygous mutations of the UGT1A1 gene can lead to these inheritable unconjugated hyperbilirubinemias, and >30 variants have been identified (4)(5). In GS, a TATAA box variant [A(TA)6TAA>A(TA)7TAA] in the promoter region of the UGT1A1 gene has been reported in Caucasian populations, and several polymorphisms in the coding region, including 211G>A (G71R), have been reported to have similar associations with GS in Japanese populations (6)(7)(8). Recently, Sugatani et al. (9) identified a T-to-G substitution in the phenobarbital-responsive enhancer module 3279 bp upstream from the UGT1A1 gene. They suggested that the −3279T>G polymorphism could be another risk factor for the development of mild hyperbilirubinemia Presumably, different combinations of the polymorphisms (haplotypes) in the UGT1A1 gene associated with GS or mild hyperbilirubinemia might produce a variety of serum total bilirubin (T-Bil) concentrations. Because these polymorphisms in the UGT1A1 gene lie in a relatively small region (Fig. 1A⇓ ), a certain extent of linkage disequilibrium (LD) among these polymorphisms is expected. Therefore, haplotype analysis is more reasonable than association analysis using any single polymorphism to reveal the genetic background of an increased serum T-Bil concentration. We analyzed the haplotype structure of the UGT1A1 gene and investigated its relationship to the serum T-Bil concentration in healthy Korean males. The study participants were 324 healthy Korean males [mean (SD) age, 49.8 …

Irinogenetics: What Is the Right Star?

Intérêt du génotypage de l’UGT1A1 dans le cadre du traitement des cancers digestifs par irinotécan

Pazopanib-Induced Liver Toxicity in Patients With Metastatic Renal Cell Carcinoma: Effect of UGT1A1 Polymorphism on Pazopanib Dose Reduction, Safety, and Patient Outcomes.