Effects of Gly71Arg mutation in UGT1A1 gene on neonatal hyperbilirubinemia: a systematic review and meta-analysis

Developing and evaluating a predictive model for neonatal hyperbilirubinemia based on UGT1A1 gene polymorphism and clinical risk factors

Background

Neonatal hyperbilirubinemia (NHB) is one of the most common diseases in the neonatal period. Without timely diagnosis and treatment, it can lead to long-term complications. In severe cases, it may even result in fatality. The UGT1A1 gene and clinical risk factors play important roles in the development and progression of NHB.

Methods

In this study, we conducted a cohort study and analyzed 3258 newborns from the Jilin Women And Children Health Hospital in northern China, including 372 children with hyperbilirubinemia. We established a predictive model using a logistic regression model based on clinical risk factors and the polymorphism of the G211A locus in the UGT1A1 gene of newborns. Furthermore, the performance of the prediction model was evaluated using the ROC curve.

Results

The logistic regression model indicates that the following factors are associated with an increased risk of NHB: the time when stool turns yellow [P ≤ 0.001, OR 1.266 (95% CI: 1.125-1.425)]; neonatal cephalohematoma [P ≤ 0.001, OR 33.642 (95% CI: 21.823-51.861)]; hemolytic disease of newborn [P ≤ 0.001, OR 33.849 (95% CI: 18.589-61.636)]; neonatal weight loss [P ≤ 0.001, OR 11.275 (95% CI: 7.842-16.209)]; neonatal premature rupture of membranes (PROM) history [P = 0.021, OR 1.422 (95% CI: 1.056-1.917)]; genetic polymorphism at the UGT1A1 gene G211A locus. Gestational age is a protective factor [P ≤ 0.001, OR 0.766 (95% CI: 0.686-0.855)]. Compared to natural labor, cesarean section is a protective factor [P = 0.011, OR 0.711 (95% CI: 0.546-0.926)], while assisted delivery is a risk factor [P = 0.022, OR 2.207 (95% CI: 1.121-4.346)]. The area under the curve (AUC) of this prediction model is 0.804 (95% CI: 0.777-0.831), indicating good discrimination ability and value for predicting the risk of NHB after birth.

Conclusion

We have developed and evaluated a predictive model that combines UGT1A1 gene polymorphism and clinical risk factors for the first time. By using this nomogram and taking into account the results of serum total bilirubin measurement or transcutaneous bilirubin measurement, early prediction of the risk of neonatal hyperbilirubinemia can be achieved.

Clinical and genetic risk factors associated with neonatal severe hyperbilirubinemia: a case-control study based on the China Neonatal Genomes Project

Objective: We aimed to investigate the clinical and genetic risk factors associated with neonatal severe unconjugated hyperbilirubinemia. Methods: This was a retrospective, 1:1 matched, case-control study. We included 614 neonates diagnosed with severe unconjugated hyperbilirubinemia (serum total bilirubin level ≥425 μmol/L or serum total bilirubin concentration that met exchange transfusion criteria) from the China Neonatal Genomes Project in Children's Hospital of Fudan University. Clinical exome sequencing data were analyzed using a data analysis pipeline of Children's Hospital of Fudan University. The factors associated with severe unconjugated hyperbilirubinemia were assessed using univariable and multivariable logistic regression analyses. Interaction analyses were examined between clinical and genetic risk factors. Results: ABO/Rh incompatibility hemolysis (odds ratio [OR] 3.36, 95% confidence interval [CI] 2.32-4.86), extravascular hemorrhage (OR 2.95, 95% CI 2.24-3.89), weight loss (OR 5.46, 95% CI 2.88-10.36), exclusive breastmilk feeding (OR 3.56, 95% CI 2.71-4.68), and the homozygous mutant of UGT1A1 211G>A (OR 2.35, 95% CI 1.54-3.59) were all identified as factors significantly associated with severe unconjugated hyperbilirubinemia. The presence of UGT1A1 211G>A mildly increased the risk of severe unconjugated hyperbilirubinemia caused by ABO/Rh incompatibility hemolysis (OR 3.98, 95% CI 2.19-7.23), although the effect is not statistically significant. Conclusion: ABO/Rh incompatibility hemolysis, extravascular hemorrhage, weight loss, exclusive breastmilk feeding, and the homozygous mutant of UGT1A1 211G>A were found to be risk factors for severe unconjugated hyperbilirubinemia. Clinical factors remain the most crucial and preventable determinants in managing severe unconjugated hyperbilirubinemia, with a minimal genetic contribution. The establishment of preconception care practices and the reinforcement of screening for the aforementioned risk factors are essential steps for preventing severe unconjugated hyperbilirubinemia.

Polymorphisms in gene UGT1A1 modify the association of prenatal exposure to polycyclic aromatic hydrocarbons with congenital heart diseases risk

INTRODUCTION

Prenatal exposure to polycyclic aromatic hydrocarbons (PAHs) is a risk factor for the occurrence of congenital heart diseases (CHDs). Genetic susceptibility to PAHs metabolism may modify the exposure-risk relationship. The role of uridine diphosphoglucuronosyl transferase 1A1 (UGT1A1) genetic polymorphisms for modulating the impacts of prenatal PAHs exposure on the risk of CHDs remains to be discovered.

OBJECTIVE

The aim of this study was to investigate whether maternal UGT1A1 genetic polymorphisms are associated with fetal susceptibility to CHDs and to assess whether the risk is modified by maternal PAHs exposure.

METHODS

Maternal urinary biomarker of PAHs exposure was determined in 357 pregnant women with CHDs fetuses and 270 controls (pregnant women carrying fetuses without major congenital malformations). Urinary 1-hydroxypyrene-glucuronide (1-OHPG) concentration, a sensitive biomarker for PAHs exposure, was measured using ultra-high-performance liquid chromatography coupled with tandem mass spectrometry. Maternal single nucleotide polymorphisms (SNPs) in UGT1A1, including rs3755319, rs887829, rs4148323, rs6742078, and rs6717546, were genotyped using an improved multiplex ligation detection reaction (iMLDR) technique. Unconditional logistic regression was performed to determine the impacts of UGT1A1 polymorphisms on the risks of CHDs and their subtypes. Generalized multifactor dimensionality reduction (GMDR) was used to analyze the gene-gene and gene-PAHs exposure interactions.

RESULTS

None of the selected UGT1A1 polymorphisms was independently associated with the risk of CHDs. The interaction between SNP rs4148323 and PAHs exposure was observed to be associated with CHDs (p< .05). Pregnant women with high-level PAHs exposure and rs4148323 had an increased risk of carrying CHDs fetuses (GA-AA vs. GG: aOR = 2.00, 95% CI = 1.06-3.79). Moreover, the joint effect of rs4148323 and PAHs exposure was found to be significantly associated with risks of septal defects, conotruncal heart defects, and right-sided obstructive malformations.

CONCLUSIONS

Maternal genetic variations of UGT1A1 rs4148323 may modify the association between prenatal PAHs exposure and CHDs risk. This finding needs to be further confirmed in a larger-scale study.

Bilirubin metabolism and UDP-glucuronosyltransferase 1A1 variants in Asians: Pathogenic implications and therapeutic response

In the Asian general population, at least six single-nucleotide variants (SNVs) in the UDP-glucuronosyltransferase (UGT) 1A1 gene have been identified: -3279T>G, -53A(TA)₆ TAA>A(TA)₇ TAA, 211G>A, 686C>A, 1091C>T, and 1456T>G. Each of these six SNVs was observed in at least four ethnic groups of the 12 Asian populations studied. In East Asian populations, the descending frequency of these six SNVs was as follows: -3279G>[-53A(TA)₇ TAA, 211A]>(686A, 1091T)>1456G. Because of the presence of linkage disequilibrium and the expulsion phenomenon, when the SNVs -3279G, -53A(TA)₇ TAA, 211A, and 686A were simultaneously involved, 15 instead of the estimated 81 genotypes were observed. Those carrying 686AA or 1456GG developed Gilbert's syndrome or Crigler-Najjar syndrome type 2. Both -53A(TA)₇ TAA/A(TA)₇ TAA and 211AA are the main causes of Gilbert's syndrome in East Asian populations. In East Asian populations, the 211AA genotype is the main cause of neonatal hyperbilirubinemia, whereas -53A(TA)₇ TAA/A(TA)₇ TAA exerts a protective effect on hyperbilirubinemia development in neonates fed with breast milk. Both 211A and -53A(TA)₇ TAA are significantly associated with adverse drug reactions induced by irinotecan (one of the most widely used anticancer agents) in Asians. However, at least three common SNVs (-3279G, -53A(TA)₇ TAA, and 211A) should be comprehensively analyzed. This study investigated the clinical significance of these six SNVs and demonstrated that examining UGT1A1 variants in Asian populations is considerably challenging.

Effect of the genetic mutant G71R in uridine diphosphate-glucuronosyltransferase 1A1 on the conjugation of bilirubin

We aimed to investigate the effect of the genetic mutant G71R (c. 211G > A) in uridine diphosphate (UDP)-glucuronosyltransferase 1A1 (UGT1A1) on the glucuronidation of unconjugated bilirubin. The UGT1A1 wild-type and mutant G71R gene sequences were inserted into the lentiviral vector GV358 plasmid and then transfected into COS-7 cells. Real-time polymerase chain reaction and western blot analyses were used to determine mRNA and protein expression levels of UGT1A1, respectively. High-performance liquid chromatography was used to quantitate the levels of conjugated bilirubin. The results showed no significant difference in the mRNA and protein expression levels between the UGT1A1 wild-type and G71R homozygous and heterozygous mutants. The level of conjugated bilirubin reached a maximum in wild-type UGT1A1-transfected COS-7 cells. However, relative to the UGT1A1 wild-type, conjugated bilirubin concentrations were 71 and 22% with G71R heterozygous- and G71R homozygous-transfected COS-7 cells, respectively. In conclusion, we successfully established in vitro cell models of the UGT1A1 wild-type and the G71R homozygous and heterozygous mutants using a lentiviral vector. Furthermore, the catalytic activity for unconjugated bilirubin was lower in the mutant G71R than the UGT1A1 wild-type enzyme, and a weaker effect was observed in the homozygote.

The n-butanol fraction of the Xiao-Chai-Hu decoction alleviates the endocrine disturbance in the liver of mice exposed to lead

ETHNOPHARMACOLOGICAL RELEVANCE

Lead is a toxic heavy metal that causes health risks globally. However, the mechanism of endocrine poisoning and detoxification of lead poisoning, especially in the liver, still needs to be studied. Xiao-Chai-Hu decoction (XCHD) is regarded as an antidote and an anti-hepatotoxic traditional prescription that has been recorded in the pharmacopeia of the People's Republic of China.

AIM OF THE STUDY

The study aimed to probe the hepatoprotective activity of XCHD in the regulation of endocrine dysfunction in the liver and its molecular mechanism.

MATERIALS AND METHODS

The mice from the Institute of Cancer Research (ICR) were exposed to different concentrations of XCHD and lead. Then, serum biochemical indices and liver pathology were analyzed. The key differential genes were detected by qRT-PCR and Western blot.

RESULTS

According to the biochemical and histopathological analysis, XCHD-NBA was the most effective in attenuating lead-induced hepatotoxicity. From the transcriptome, we analyzed the key genes of XCHD-NBA in the regulation of lead toxicity, including Tubb2a, Stip1, Cyp4a12a, Cyp2c50, Ugt1a1, Cyp3a11, Cyp4a12b, Ahsa1, Cyp2c54, Tubb4b, Esr1, Hsp90aa1, Tuba1a, Tuba1c, and Hsph1. We also analyzed the main components of XCHD-NBA by LC-MS. Because of their extensive role in regulating the endocrine function, baicalin and glycyrrhizin were identified as the main active components of XCHD in regulating endocrine disorders caused by lead.

CONCLUSIONS

Lead can disturb the endocrine regulatory process of the liver, while XCHD-NBA alleviates lead-induced liver injury by regulating the endocrine regulatory process.

The relationship between hyperbilirubinemia and the promoter region and first exon of UGT1A1 gene polymorphisms in Vietnamese newborns

BACKGROUND

To investigate the relationship between unexplained indirect hyperbilirubinemia of Vietnamese newborns and the polymorphism of the promoter TATA box and exon 1 of bilirubin uridine diphosphate glucuronosyltransferase (UGT1A1) gene.

METHODS

A total of 149 neonates were divided into the hyperbilirubinemia group (n = 99) and control group (n = 50). The gene polymorphisms of UGT1A1 gene in the two groups were detected by PCR and direct sequencing, which revealed the relationship between UGT1A1 polymorphism with neonatal hyperbilirubinemia of neonates. The types of UGT1A1 polymorphism in the hyperbilirubinemia group and the peak total serum bilirubin (PSB) levels with different genotypes were observed.

RESULTS

(1) (TA)7 insertion mutation, 211G>A, 189C>T, 190G>A, 378C>T and 686C>A were detected. (2) The allele frequency of 211G>A allele mutation was significantly different between the two groups (p < 0.05). (3) Logistic regression analysis showed that homozygosity and heterozygosity of 211G>A were both significantly associated with neonatal hyperbilirubinemia. (4) In the hyperbilirubinemia group, the peak total serum bilirubin level of 211G>A homozygous neonates was higher than that of the wild-type neonates (p < 0.05).

CONCLUSIONS

We noted that there was an association between neonates with unexplained indirect hyperbilirubinemia in Vietnam and the polymorphism of UGT1A1c.211G>A. In addition, the homozygous 211G>A polymorphism was related to the degree of hyperbilirubinemia.

IMPACT

Our article provided data on UGT1A1 polymorphism distribution in the Vietnamese population, which have not been reported yet. Our findings revealed that mutations in UGT1A1 gene are risk factors for unexplained hyperbilirubinemia in Vietnamese neonates. Our article will strengthen the cognition of neonatal jaundice at the genetic level in the pediatric field in Vietnam.

The role of UGT1A1 (c.-3279 T > G) gene polymorphisms in neonatal hyperbilirubinemia susceptibility

Background

Neonatal hyperbilirubinemia (NNH) is a common disease in newborns. This research study aimed to assess the associations between uridine diphospho-glucuronate-glucuronosyltransferase 1A1 (UGT1A1, c.-3279 T > G) polymorphisms and NNH risk.

Methods

We searched PubMed, the Cochrane Library, and the Embase electronic databases. All published eligible studies before July 1, 2019, were searched for this meta-analysis.

Results

We identified 7 independent studies including 1560 cases. The data showed that in the general population, compared with the GT + GG vs TT and GG vs TT, c.-3279 T > G (rs4124874) was significantly related to a higher NNH risk (GG vs TT: OR = 1.865, 95% CI: 1.031–3.373, P = 0.039; GT + GG vs TT: OR = 1.331, 95% CI: 1.055–1.679, P = 0.016). Although not statistically significant, the data showed that c.3279 T > G had a tendency to be associated with NNH under the allele model and GG vs GT + TT in the overall population (G vs T: OR = 1.288, 95% CI: 0.982–1.689, P = 0.067; GG vs TT + GT: OR = 1.583, 95% CI: 0.947–2.647, P = 0.080).

Conclusion

The UGT1A1 gene c.-3279 T > G (rs4124874) polymorphism increased susceptibility to NNH, especially for the comparison of GT + GG vs TT and GG vs TT. In the future, we can use homozygous state of the UGT1A1 gene c.-3279 T > G (rs4124874) polymorphism for the diagnosis and screening of molecular biomarkers in NNH patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12881-020-01155-2.

Effects of variation status and enzyme activity for UDP-glucuronosyltransferase 1A1 gene on neonatal hyperbilirubinemia

BACKGROUND

We found that Taiwanese adults carrying genotypes of UDP-glucuronosyltransferase (UGT) 1A1 with enzyme activity ≤40% of normal were at high risk for developing Gilbert's syndrome. However, the relationship between UGT1A1 activity and neonatal hyperbilirubinemia has never been evaluated for Taiwanese.

METHODS

We enrolled 141 hyperbilirubinemic neonates partially fed supplementary infant formula and 432 controls; and 112 hyperbilirubinemic neonates exclusively breastfed and 493 controls. The five single nucleotide polymorphisms (SNPs) at nucleotides -53, 211, 686, 1091 and 1456 in the UGT1A1 gene were determined and UGT1A1 activity was estimated. Odds ratios (ORs) of variation status in the UGT1A1 gene and enzyme activity for the development of neonatal hyperbilirubinemia were calculated, respectively.

RESULTS

For neonates partially fed supplementary infant formula, the adjusted OR (AOR) for the development of hyperbilirubinemia was significantly higher in the neonates carrying the homozygous variation (211AA) in the UGT1A1 gene than for those carrying the wild type (AOR = 6.00, p < 0.001). Only the AOR of those carrying UGT1A1 activity ranked 31-40% of normal was statistically significant (AOR = 3.16, p < 0.001). For the hyperbilirubinemic neonates exclusively breastfed, AOR for the development of hyperbilirubinemia is positively correlated to degree of variation (AOR = 1.95, 2.19 and 4.53; with p = 0.003, 0.05 and < 0.001, respectively), while the effect of UGT1A1 enzyme activity was varied (AOR = 1.02-3.72, with p = 0.95∼<0.001).

CONCLUSION

The estimated enzyme activity depending on combination of SNPs (genotypes) in the UGT1A1 gene could not be utilized to explain the development of neonatal hyperbilirubinemia. We reconfirm that the -53 A(TA)₇TAA/A(TA)₇TAA is not, while the 211AA is a risk factor for the development of neonatal hyperbilirubinemia in Taiwanese.

[Research advances in neonatal hyperbilirubinemia and gene polymorphisms]

Hyperbilirubinemia is a prevalent disease in neonates and is also a main reason for hospitalization within the first week after birth, and this disease is mainly caused by the imbalance between production and elimination of bilirubin. Uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1), organic anion transporter polypeptide 2 (OATP2), heme oxygenase 1 (HO-1), and biliverdin reductase A (BLVRA) play crucial roles in the metabolism of bilirubin. More and more studies have revealed the association between the variation of the encoding genes for these enzymes and hyperbilirubinemia. This article reviews the research advances in the association between the gene polymorphisms of bilirubin metabolic enzymes and hyperbilirubinemia.

UGT1A1*28 gene polymorphism was not associated with the risk of neonatal hyperbilirubinemia: a meta-analysis

Background: This study aimed to evaluate the relationship between UGT1A1*28 gene polymorphism and the risk of neonatal hyperbilirubinemia (NHBI).Methods: The studies meet certain selection condition which was obtained from databases such as PubMed, Embase, and Cochrane Library. Newcastle-Ottawa Scale (NOS) was used to evaluate the quality of included studies. Meta-analysis was performed according to criteria such as country. Hardy-Weinberg's equilibrium (HWE) tests were performed on the control group using chi-square test, while the evaluation index was represented by odds ratio (OR) and 95% confidence interval (CI). Egger's test and sensitivity analysis were used to evaluate the publication bias and reliability, repetitively.Results: Totally, four studies with high overall quality were enrolled in this study. No association was observed between UGT1A1*28 gene polymorphisms and NHBI in allele model (TA7 versus TA6, OR (95% CI) = 2.13 (0.81-5.62), p = .13), codominance models (TA7/6 versus TA6/6, OR (95% CI) = 2.94 (0.90-9.57), p = .07; TA7/7 versus TA6/6, OR (95% CI) = 2.08 (0.37-11.52), p = .40), recessive model (TA7/7 versus TA6/6 + TA7/6, OR (95% CI) = 1.44 (0.41-5.14), p = .57), and dominant model (TA7/7 + TA7/6 versus TA6/6, OR (95% CI) = 2.92 (0.84-10.12), p = .09). Furthermore, there was no publication bias found in current meta-analysis.Conclusions: Gene polymorphism of UGT1A1*28 might not be associated with the risk of NHBI.

Profiling of UGT1A1*6, UGT1A1*60, UGT1A1*93, and UGT1A1*28 Polymorphisms in Indonesian Neonates With Hyperbilirubinemia Using Multiplex PCR Sequencing

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 SNaPshot^R 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.