UGT1A1 gene polymorphisms in patients with Gilbert syndrome and Crigler-Najjar syndrome type Ⅱ / 临床肝胆病杂志

Objective To investigate the differences in UGT1A1 gene mutation sites, haplotypes, and diplotypes between patients with Gilbert syndrome (GS) and those with Crigler-Najjar syndrome type Ⅱ (CN-2). Methods A retrospective analysis was performed for the clinical data of 138 patients with GS or CN-2 who attended Beijing YouAn Hospital, Capital Medical University, from January 1, 2010 to December 31, 2019, with 109 patients in the GS group and 29 patients in the CN-2 group, and the differences in mutation sites were analyzed between the two phenotypes. The Mann-Whitney U test was used for comparison of continuous data between two groups, and the chi-square test or the Fisher's exact test was used for comparison of categorical data between groups. SNPStats software was used to perform linkage disequilibrium (LD) and haplotype analyses of mutation sites. Strong LD was defined as both | D ′| and r 2 > 0.8, and moderate LD was defined as | D ′| > 0.8 and r 2 > 0.4. Results UGT1A1 gene detection was performed for all patients, and mutations mainly included -3279T > G mutation (104 patients, 75.36%) and -3152G > A mutation (82 patients, 59.42%) in the upstream promoter PBREM region, a promoter TATA box TA insertion mutation (88 patients, 63.77%), and c.211G > A mutation in Exon 1 of the coding region (66 patients, 47.83%). Compared with the CN-2 group, the GS group had a significantly higher proportion of PBREM region -3279T > G mutation (82.57% vs 48.28%, χ 2 =14.508, P A mutation (68.81% vs 24.14%, χ 2 =18.955, P (TA) 7 mutation (72.48% vs 31.03%, χ 2 =17.027, P 0.8, r 2 > 0.8) between (TA) 6 > (TA) 7 and -3152G > A and moderate LD (| D ′| > 0.8, r 2 > 0.4) between (TA) 6 > (TA) 7 and -3279T > G, between -3152G > A and -3279T > G, between (TA) 6 > (TA) 7 and c.211G > A, and between -3279T > G and c.211G > A. Haplotype frequency analysis showed that compared with the CN-2 group, the GS group had a significantly higher frequency of haplotype -3279G—-3152A—(TA) 7 (45.72% vs 17.24%, χ 2 =7.833, P =0.005) and significantly lower frequencies of c.1456G (4.10% vs 16.48%, χ 2 =4.873, P =0.027) and c.211A—c.1456G (1.86% vs 24.90%, χ 2 =15.210, P < 0.001). The diplotype analysis showed that diplotypes consisting of haplotype c.1456G or c.211A—c.1456G were associated with a higher level of total bilirubin (TBil). Conclusion There are differences in common mutation sites and major haplotypes of the UGT1A1 gene between patients with GS and those with CN-2, and the common diplotypes of CN-2 correspond to a higher level of TBil.

Research advances in congenital non-hemolytic jaundice / 临床肝胆病杂志

Congenital non-hemolytic jaundice is an important type of jaundice diseases, and except breast milk jaundice, the other types of this disease are relatively rare in clinical practice. Most of them belong to genetic and metabolic liver diseases, including Gilbert syndrome, Crigler-Najjar syndrome, and Lucey-Driscoll syndrome with an increase in unconjugated bilirubin and Dubin-Johnson syndrome and Rotor syndrome with an increase in conjugated bilirubin. With reference to the recent literature in China and foreign countries, this article reviews the pathogenesis, genetic characteristics, diagnosis, treatment, and differential diagnosis of six types of hereditary congenital unconjugated jaundice.

Research advances in mutation characteristics of the UGT1A1 gene in Gilbert syndrome and its influence on intrahepatic and extrahepatic systems / 临床肝胆病杂志

Gilbert syndrome is the most common type of hereditary hyperbilirubinemia with a high incidence rate. This article briefly describes the research advances in epidemiological characteristics of Gilbert syndrome, common UGT1A1 gene mutation sites, and the influence of Gilbert syndrome on intrahepatic and extrahepatic diseases. It is pointed out that an understanding of these aspects plays an important role in the diagnosis and treatment of Gilbert syndrome and the prevention and treatment of intrahepatic and extrahepatic diseases.

Hiperbilirrubinemias hereditarias: un diagnóstico diferencial a considerar en ictericia / Hereditary hiperbilirrubinemias: a differential diagnosis to considerer in icterus

Las hiperbilirrubinemias hereditarias (HBH) son patologías originadas por defectos en las enzimas y proteínas que participan del metabolismo de la bilirrubina. El clearence de bilirrubina incluye captación y almacenamiento en hepatocitos, conjugación, excreción hacia la bilis y recaptura de su forma conjugada por hepatocitos. Las HBH varían de acuerdo a su patogenia, presentación clínica, niveles de bilirrubinemia y tratamientos disponibles. En general son poco frecuentes, a excepción del Síndrome de Gilbert. Están las que son de predominio indirecto, como el Síndrome de Gilbert y el de Crigler-Najjar, y las de predominio directo, como el Síndrome de Dubin-Johnson y el de Rotor. En general no requieren tratamiento específico y tienen curso benigno, a excepción del Síndrome de Crigler-Najjar para el cual existen medidas terapéuticas específicas a considerar, teniendo un pronóstico reservado para algunas de sus formas de presentación. Es importante el conocimiento de estos síndromes dado el alto índice de sospecha requerido para su diagnóstico y para su diferenciación de otras patologías hepatobiliares de mayor riesgo y severidad.

Hereditary hiperbilirrubinemias (HBH) are pathologies originated from the defect of the enzymes and proteins involved in the metabolism of bilirubin. The bilirubin clearance includes uptake and storage in hepatocytes, conjugation, excretion into bile and recapture of its conjugated form by hepatocytes. HBH vary according to their pathogenesis, clinical presentation, levels of bilirubin and available treatments. Generally they are infrequent, except for Gilbert Syndrome. There are those with indirect bilirubin predominance, such as Gilbert and Crigler-Najjar syndromes, and those with direct bilirubin predominance, including Dubin-Johnson and Rotor syndromes. In general, they do not require specific treatment and have a benign course, with the exception of the Crigler-Najjar Syndrome, for which there are specific therapeutic measures to consider, as well as a reserved prognosis for some of their forms of presentation. The knowledge of these syndromes is important 2 given the high index of suspicion required for its diagnosis and for its differentiation from other hepatobiliary pathologies of greater risk and severity.

Study on spectrum of UGT1A1 mutations in connection with inherited non-hemolytic unconjugated hyperbilirubinemia / 中华肝脏病杂志

Objective@#To compare and analyze patient’s general condition, changes in laboratory parameters, and the spectrum of UGT1A1 mutations in patients with inherited non-hemolytic unconjugated hyperbilirubinemia.@*Methods@#A retrospective study was conducted at Nanjing Second Hospital from January 2015 to July 2018 and patients’ demographic characteristics, liver function test, and UGT1A1 gene were analyzed. The categorical variable data were compared by χ 2 test. The normal distribution continuous variable data were compared by t-test and the non-normal distribution continuous variable data were compared using Mann-Whitney U test.@*Results@#Of the 51 patients with inherited non-hemolytic unconjugated hyperbilirubinemia, 44 (86.3%) were Gilbert’s syndrome (GS) and seven (13.7%) were Crigler-Najjar syndrome type II (CNS- II). The male to female ratio was 2.9:1 and the average age was 36.11 ± 13.17 years. Six variant types were detected: C. -40_-39insTA, C. -3279T > G, c.211G > A (p.G71R), c.686C > A (p.P229Q), c.1091C > T (p.P364L), c.1456T > G (P.Y486D). Among them, c.211G > A accounted for 58.82% (30/51), c.-40_-39insTA accounted for 27.5% (14/51), and c.1456T > G accounted for 25.5% (13/51). The total bilirubin(TB) and unconjugated bilirubin (UCB) in CNS-II patients were significantly higher than GS patients[155.91 (130 ~ 207) vs. 38.25(29 ~ 52.15) μmol/L, U = 0, P < 0.01; 144.13 (120.8 ~ 197) vs. 30.00 (21.7 ~ 46.75) μmol/L, U = 0.00, P < 0.01, respectively]. Exon mutations of c.1091C > T and c.1456T > G were statistically significant(P < 0.01).There were no differences in age, TB, UCB, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) between the c.211G > A homozygous variants and heterozygous variants (P > 0.05).@*Conclusion@#The common pathogenic mutations of UGT1A1 gene were c.211G > A, c.-40_-39insTA, c.1456T > G. c.211G > A. The mutation has little effect on the level of total bilirubin, but c.1091C > T, c.1456T > G mutations has great influence on the level of total bilirubin.

The establishment of a high resolution melting analysis based rapid screening system for UGT1A1 gene mutation / 中华检验医学杂志

Objective To develop a high-resolution melting ( HRM ) assay for rapidly screening Gilbert syndrome ( GS) and Crigler-Najjar syndrome ( CNS) associated with UGT1A1 defects.Method Methodology was developed .Then, we applied the established method to analyze 61 clinical samples from neonatal patients with severe unexplained unconjugated hyperbilirubinemia .Neonates with known risk factors for developing hyperbilirubinemia , such as ABO hemolysis, G6PD deficiency, sepsis, hypoxic ischemic encephalopathy were excluded .Five pairs of PCR primers were designed to detect the five common mutations (G211A, C686A, C1091T, C1352T and T1456G) in Asia population.PCR and HRM Assay conditions were optimized.UGT1A1 genotyping in clinical samples was performed by using the established HRM analysis , and all results were subsequently confirmed by direct DNA sequencing .Results The mutants were readily differentiated by using HRM analysis .In this study, 42 neonates were identified with UGT1A1 mutation, and 4 different known variants were detected .Conclusion HRM analysis in this study was economical, convenient, rapid, effective for screening UGT1A1 gene mutations, which can serve as an reliable method for the clinical diagnosis of GS and CNS and the large-scale molecular epidemiological research of UGT1A1 gene-related diseases.

Síndrome Lucey-Driscoll - Reporte de caso / Lucey-Driscoll Syndrome - Case Report

La hiperbilirrubinemia no conjugada es una condición producida por una alteración en el proceso de conjugación y excreción de la bilirrubina. La glucoronosiltransferasa uridin difosfato es la responsable en la conjugación de la bilirrubina, es codificada por el gen de UGT1A1 localizado en el brazo q del cromosoma 2 locus 37.1. La variación genética del UGT1A1 puede producir diferentes fenotipos desde el más severo llamado Sindrome Crigler-Najjar Tipo I y II, pasando por el Sindrome de Gilbert; hasta una hiperbilirrubinemia transitoria neonatal o síndrome LUCEY-DRISCOLL (HBLRTFN) fenotipo OMIM 237900 con producción de kernicterus y parálisis cerebral pero con resolución espontánea, todos ellos de herencia autosómica recesiva causada por mutación homocigota o heterocigota en el gen UGT1A1. En este reporte se presenta un caso en un recién nacido que a los 7 días presenta hiperbilirrubinemia severa con kernicterus, y la prueba genética muestra mutación heterocigota del *28 del gen UGT1A1

Unconjugated hyperbilirubinemia is produced by alteration in conjugation and excretion process of bilirubin. Glucoronosiltransferasa Uridine diphosphate enzyme is involved in bilirubin conjugation. Is encoded by the UGT1A1 gene located in chromosome 2q locus 37.1. UGT1A1 genetic variation can produce different phenotypes Crigler-Najjar Syndrome Type I and II, Gilbert Syndrome, and hyperbilirubinemia transited familial LUCEY-DRISCOLL (HBLRTFN) syndrome with kernicterus production but with spontaneous resolution, all autosomal recessive. We present here a case of newborn 7 days old with severe hyperbilirubinemia , kernicterus, and genetic testing shows heterozygous mutation of the UGT1A1 * 28 gene

Role of UGT1A1 gene polymorphism in the pathogenesis of Gilbert syndrome / 临床肝胆病杂志

As a bilirubin metabolic disorder, Gilbert syndrome belongs to the category of congenital non-hemolytic jaundice. Deficiency or decrease in the activity of bilirubin-uridine diphosphate glucuronyltransferase (UGT) is an important reason for the pathogenesis of Gilbert syndrome. UGT1A1, an isoenzyme of UGT, is a key enzyme to direct bilirubin in the liver. Mutations in UGT1A1 gene lead to the structural abnormality of UGT, and thus result in the decrease or loss of the ability of UGT to bind bilirubin. This article summarizes the research advances in the role of UGTA1 and its polymorphism in the pathogenesis and diagnosis of Gilbert syndrome.

Coexistence of Gilbert Syndrome and Hereditary Spherocytosis in a Child Presenting with Extreme Jaundice / 대한소아소화기영양학회지

Gilbert syndrome is the most common inherited disorder of bilirubin glucuronidation. It is characterized by intermittent episodes of jaundice in the absence of hepatocellular disease or hemolysis. Hereditary spherocytosis is the most common inherited hemolytic anemia and is characterized by spherical, osmotically fragile erythrocytes that are selectively trapped by the spleen. The patients have variable degrees of anemia, jaundice, and splenomegaly. Hereditary spherocytosis usually leads to mild-to-moderate elevation of serum bilirubin levels. Severe hyperbilirubinemia compared with the degree of hemolysis should be lead to suspicion of additional clinical conditions such as Gilbert syndrome or thalassemia. We present the case of a 12-year-old boy with extreme jaundice and nausea. The diagnosis of hereditary spherocytosis was confirmed by osmotic fragility test results and that of Gilbert syndrome by genetic analysis findings.

Prevalencia de síndrome de Gilbert y sus determinantes genéticas en población chilena / Prevalence of Gilbert syndrome and its genetic determinants in Chile

Background: In Europeans the TATA box TA7 repeat promoter variant in the UGT1A1 gene (UGT1A1*28) is the major determinant of bilirubin levels. Aim: To study the prevalence of Gilbert Syndrome (GS) and its genetic determinants in Chile. Material and Methods: Three different studies were conducted. The prevalence of GS in Chile was assessed in 991 subjects with normal liver tests (ALT and GGT) from the 2nd National Health Survey. We defined GS as a total bilirubin (TB) between 1.4-5mg/dL. The second study assessed the genotype prevalence of SNP rs6742078 (in LD with UGT1A1*28) and rs4149056 in 500 DNA samples of non-related Hispanics. Finally, a case-control study was designed to assess the phenotype-genotype correlation. UGT1A1*28 and rs4149056 variants were determined by direct sequencing and allelic discrimination assays (TaqMan), respectively. Results: Prevalence of GS in the general Chilean population was 2.6% (4.5% in males and 0.5% in female). No correlation with age, educational level or home location was found. Genotypes for UGT1A1*28 (TA6/6 50.5%, TA6/7 37.8%, TA7/7 11.7%) and rs4149056 (TT 74.1%, CT 22.8%, and CC 3.1%) variants were similar to Europeans. In the case-control study, most patients with GS were homozygotes for UGT1A1*28 (TA7/7, 74%). Of note, 44% of patients with intermediate TB levels were also TA7/7, compared to 7% in normal subjects. SLCO1B1 genotype was not correlated with TB levels. Conclusions: While the prevalence of GS was lower in Chile compared to Europeans (~5%), the prevalence of UGT1A1*28 homozygotes was similar (~12%). In Chilean Hispanics, the UGT1A1*28 variant explain 75% of GS phenotype.

A Case of Hereditary Spherocytosis Coexisting with Gilbert's Syndrome / 대한소화기학회지

We recently encountered a case of hereditary spherocytosis coexisting with Gilbert's syndrome. Patient was initially diagnosed with Gilbert's syndrome and observed, but other findings suggestive of concurrent hemolysis, such as splenomegaly and gallstones were noted during the follow-up period. Therefore, further evaluations, including a peripheral blood smear, osmotic fragility test, autohemolysis test, and red blood cell membrane protein test were performed, and coexisting hereditary spherocytosis was diagnosed. Genotyping of the conjugation enzyme uridine diphosphate-glucuronosyltransferase was used to confirm Gilbert's syndrome. Because of the high prevalence rates and similar symptoms of these 2 diseases, hereditary spherocytosis can be masked in patients with Gilbert's syndrome. In review of a case and other article, the possibility of the coexistence of these 2 diseases should be considered, especially in patients with unconjugated hyperbilirubinemia who also have splenomegaly and gallstones.

A Case of Gilbert's Syndrome with Severe Neonatal Hyperbilirubinemia

Gilbert's syndrome is caused by a reduction in the activity of uridine diphosphate glucuronosyltransferase (UGT) and induces chronic, non-hemolytic unconjugated hyperbilirubinemia. It has been suggested that 3-10% of the population has Gilbert's syndrome. Commonly, Gilbert's syndrome causes mild symptoms. However, a case of Gilbert's syndrome with severe neonatal hyperbilirubinemia is presented here. The patient developed jaundice three days after birth. Five days after birth, the patient's total serum bilirubin level was 34 mg/dL. The patient received intensive phototherapy and was given oral phenobarbital. Hemolytic hyperbilirubinemia was excluded on the basis of laboratory tests. Heterozygote polymorphisms of the promoter region (-3279T>G) and exon 1 (211G>A) were found in UGT1A1 gene. After discharge, the patient did not require any further treatment. This is the first case of proven Gilbert's syndrome with severe neonatal hyperbilirubinemia in Korea.

A Case of Gilbert's Syndrome with Severe Neonatal Hyperbilirubinemia

Gilbert's syndrome is caused by a reduction in the activity of uridine diphosphate glucuronosyltransferase (UGT) and induces chronic, non-hemolytic unconjugated hyperbilirubinemia. It has been suggested that 3-10% of the population has Gilbert's syndrome. Commonly, Gilbert's syndrome causes mild symptoms. However, a case of Gilbert's syndrome with severe neonatal hyperbilirubinemia is presented here. The patient developed jaundice three days after birth. Five days after birth, the patient's total serum bilirubin level was 34 mg/dL. The patient received intensive phototherapy and was given oral phenobarbital. Hemolytic hyperbilirubinemia was excluded on the basis of laboratory tests. Heterozygote polymorphisms of the promoter region (-3279T>G) and exon 1 (211G>A) were found in UGT1A1 gene. After discharge, the patient did not require any further treatment. This is the first case of proven Gilbert's syndrome with severe neonatal hyperbilirubinemia in Korea.

A Study of Polymorphism in UDP-glucuronosyltransferase 1 (UGT-1A1) Promoter Gene in Korean Patients with Gilbert's Syndrome / 대한간학회지

BACKGROUNDS/AIMS: Hepatic glucuronidating activity, essential for efficient biliary excretion of bilirubin, is reduced to about 30 percent of normal in patients with Gilbert's syndrome. Patients with Gilbert's syndrome have an additional TA insertion in the A(TA)TAA of UDP-glucuronosyltransferase 1 (UGT-1A1) promoter gene. This results in reduced frequency and accuracy of transcription initiation and enzyme activity. The frequency and location of the mutation vary according to races. This study was done to determine the UGT-1A1 promoter gene mutation in Korean cases of Gilbert's syndrome. METHODS: Promoter regions of the gene for bilirubin UGT-1A1 in twelve patients with Gilbert's syndrome and twenty healthy subjects (controls) were sequenced. RESULTS: 1) Among twelve Gilbert's syndrome five patients were homozygous for A(TA)6/6TAA, two were homozygous for A(TA)7/7TAA, and the other five were heterozygous for A(TA)6/7TAA. The prevalence of A(TA)TAA mutation was 58.3 percent. 2) Among twenty healthy subjects seventeen were homozygous for A(TA)6/6TAA, one was homozygous for A(TA)7/7TAA, and two were heterozygous for A(TA)6/7TAA. The prevalence of A(TA)TAA mutation was 15 percent. 3) The prevalence of A(TA)TAA mutation in Gilbert's syndrome patients was significantly higher than in the controls (p=0.018). CONCLUSION: Although the prevalence of A(TA)TAA mutation in Korean patients with Gilbert's syndrome is significantly higher than in the controls, the mutations of the promoter region of UGT-1A1 gene appear not to be the main or sole cause in Gilbert's syndrome in Korea since the prevalence of A(TA)TAA mutation is not so high. Further studies to determine the relationship between other UGT-1A1 gene mutation and Gilbert's syndrome in Korea are needed.