Glucuronosyltransferase ; genetics ; Humans ; Infant, Newborn ; Jaundice, Neonatal ; genetics

Dubin-Johnson syndrome (DJS) is an autosomal recessive disorder resulting from biallelic mutations of ABCC2 gene, with long-term or intermittent conjugated hyperbilirubinemia being the main clinical manifestation. This paper aims to report the clinical features and ABCC2 genotypes of an infant with DJS. A 9.5-month-old male infant was referred to the hospital due to abnormal liver function discovered over 9 months. The major clinical presentation was prolonged jaundice since neonatal period. A series of biochemistry analysis revealed markedly elevated total bilirubin, conjugated bilirubin and total bile acids. The patient had been managed in different hospitals, but the therapeutic effects were unsatisfactory due to undetermined etiology. Physical examination revealed jaundiced skin and sclera, and a palpable liver 3 cm below the right subcostal margin with medium texture. The spleen was not enlarged. Genetic analysis revealed a splice-site variant c.3988-2A>T and a nonsense variant c.3825C>G (p.Y1275X) in the ABCC2 gene of the infant, which were inherited from his mother and father respectively. The former had not been previously reported. Then ursodeoxycholic acid and phenobarbital were given orally. Half a month later, as a result, his jaundice disappeared and the biochemistry indices improved. However, the long-term outcome needs to be observed. Literature review revealed that neonates/infants with DJS presented with cholestatic jaundice soon after birth as the major clinical feature, and the ABCC2 variants exhibited marked heterogeneity.
Bile Acids and Salts ; Bilirubin ; Humans ; Infant ; Jaundice ; Jaundice, Chronic Idiopathic ; genetics ; Male ; Multidrug Resistance-Associated Proteins ; genetics ; Ursodeoxycholic Acid

Hereditary bilirubin metabolic disorder is an important cause for jaundice. For its diverse types and similar clinical manifestations, it has been difficult to make a clear etiological diagnosis. The application of next generation sequencing in recent years has delineated the more and more genetic etiologies for jaundice. This article has reviewed the clinical manifestations and genetic etiology of bilirubin metabolic disorder jaundice, with an aim to enhance the understanding of such diseases and facilitate their clinical diagnosis and treatment, which will provide a reference for genetic counseling and/or prenatal diagnosis for the affected individuals and families.
Female ; Pregnancy ; Humans ; Metabolic Diseases/genetics* ; Jaundice/genetics* ; Bilirubin ; Genetic Counseling ; Phenotype

Patients with co-existing hereditary spherocytosis (HS) and UDP-glucuronosyltransferase 1A1 (UGT1A1) deficiency as Gilbert's syndrome (GS) have been reported, and previous studies have demonstrated an increased risk for developing gallstones in patients with co-inheritance of GS and HS. We experienced an interesting case of HS showing persistent jaundice after splenectomy, and upon further evaluation, the 25-year-old female patient was found to have HS combined with UGT1A1 deficiency. Sequence analysis of the UGT1A1 gene revealed that she was a compound heterozygote with p.[G71R; Y486D] + [Y486D] mutations, which suggests Crigler-Najjar syndrome type II rather than GS. Careful evaluation of inappropriately elevated bilirubin level compared with the degree of hemolysis is important, reflecting the therapeutic implication of splenectomy and cholecystectomy.
Adult ; Crigler-Najjar Syndrome/genetics ; Female ; Glucuronosyltransferase/*deficiency/genetics ; Heterozygote ; Homozygote ; Humans ; Jaundice/etiology/genetics ; Mutation, Missense/genetics ; Point Mutation/genetics ; Spherocytosis, Hereditary/complications/*genetics ; Splenectomy/adverse effects

Crigler-Najjar Syndrome ; genetics ; Gilbert Disease ; genetics ; Glucosephosphate Dehydrogenase Deficiency ; genetics ; Glucuronosyltransferase ; genetics ; Humans ; Infant, Newborn ; Jaundice, Neonatal ; genetics ; Polymorphism, Genetic

Sodium taurocholate cotransporting polypeptide (NTCP) deficiency is caused by SLC10A1 mutations impairing the NTCP function to uptake plasma bile salts into the hepatocyte. Thus far, patients with NTCP deficiency were rarely reported. The patient in this paper was a 5-month-19-day male infant with the complaint of jaundiced skin and sclera for 5.5 months as well as abnormal liver function revealed over 4 months. His jaundice was noticed on the second day after birth, and remained visible till his age of 1 month and 13 days, when a liver function test unveiled markedly elevated total, direct and indirect bilirubin as well as total bile acids (TBA). Cholestatic liver disease was thus diagnosed. Due to unsatisfactory response to medical treatment, the patient underwent exploratory laparotomy, cholecystostomy and cholangiography when aged 2 months. This revealed inspissated bile but unobstructed bile ducts. Thereafter, his jaundice subsided, but the aminotransferases and TBA levels gradually rose. Of note, his mother also had mildly elevated plasma TBA. Since the etiology was unclear, no specific medication was introduced. The infant has been followed up over 2 years. The aminotransferases recovered gradually, but TBA levels fluctuated within 23.3-277.7 μmol/L (reference range: 0-10 μmol/L). On SLC10A1 genetic analysis at 2 years and 9 months, both the infant and his mother proved to be homozygous for a pathogenic variant c.800C>T(p.S267F), and NTCP deficiency was thus definitely diagnosed. The findings suggest that, although only mildly increased plasma TBA is presented in adults with NTCP deficiency, pediatric patients with this disorder exhibit persistent and remarkable hypercholanemia, and some patients might manifest as cholestatic jaundice in early infancy.
Humans ; Infant ; Jaundice, Obstructive ; etiology ; Male ; Organic Anion Transporters, Sodium-Dependent ; blood ; deficiency ; genetics ; Symporters ; blood ; deficiency ; genetics

OBJECTIVE: To explore the genetic etiology in four patients with hyperbilirubinemia, and discuss the correlation between clinical characteristics and molecular basis. METHODS: The data of clinical manifestation and auxiliary examinations were collected. Genomic DNA of the four patients was extracted and analyzed by next-generation sequencing using the panel including genes involved in hereditary metabolic liver diseases. Suspected variants were verified by Sanger sequencing. RESULTS: All of the four patients were males with normal liver enzymes. It was revealed that all the patients had heterozygous variants, among which c.3011C>T, c.2443C>T and c.2556del were the variants which have not been reported previously. CONCLUSION All of the patients were diagnosed as Dubin-Johnson syndrome (DJS) caused by ABCC2 gene variants. The novel variants add to the spectrum of genetic variants of the disease. Because of the favorite prognosis, precise diagnosis can greatly reduce the psychological pressure of patients and avoid excessive treatments. At the same time, it could provide pertinent genetic counseling for the families.
DNA ; Female ; Heterozygote ; Humans ; Jaundice, Chronic Idiopathic/genetics* ; Male ; Multidrug Resistance-Associated Protein 2 ; Multidrug Resistance-Associated Proteins/genetics* ; Phenotype

Organic anion transporter 2 (OATP2) is an uptake transporter located on the basolateral membrane of human hepatocytes. It mediates the transportation of various organic solutes including bilirubin and impacts bilirubin metabolism. It is encoded by the gene of solute carrier organic anion transporter family member 1B1 and the gene variants that inhibit hepatic bilirubin uptake function may reduce the normal functional level of bilirubin elimination and result in neonatal hyperbilirubinemia. In recent years, some studies have indicated that variants of SLCO1B1 are associated with neonatal jaundice. This article reviews the research advance in SLCO1B1 with respect to the structure and function and the relationship between SLCO1B1 mutations and neonatal jaundice.
Glucosephosphate Dehydrogenase Deficiency ; genetics ; Humans ; Infant, Newborn ; Jaundice, Neonatal ; genetics ; Organic Anion Transporters ; genetics ; Polymorphism, Genetic ; Solute Carrier Organic Anion Transporter Family Member 1b1 ; genetics

OBJECTIVETo study the correlation between glucose-6-phosphate dehydrogenase (G-6-PD) activities and three common mutations of G-6-PD gene G1388A, G1376T and A95G and investigate the effects of G-6-PD gene mutations on neonatal jaundice in Nanning, Guangxi.

METHODSOne hundred and twenty-four neonates from Nanning, Guangxi, with hyperbilirubinemia were enrolled. The ARMS-PCR and PCR/REA methods were used to determine G-6-PD gene mutations. G-6-PD activities were measured using the NBT method. The incidence of acute bilirubin encephalopathy and the peak bilirubin concentration 72 hrs after birth were compared between the neonates with different genotypes and between the G-6-PD mutation and normal groups. The risk of blood serum bilirubin >340 mumol/L was evaluated by logistic regression analysis.

RESULTSOf the 124 cases, gene mutations were found in 37 cases, including G1388A (n=20), G1376T (n=14), A95G (n=4) and G1388A+A95G (n=1). Five cases (25%) showed normal G-6-PD activities in the G1388A gene mutation group and 4 (29%) had normal G-6-PD activities in the G1376T G1388A gene mutation group. All of 4 cases of A95G G1388A gene mutation showed a deficiency of G-6-PD activities. There were no significant differences in the incidence of acute bilirubin encephalopathy and the peak bilirubin concentration 72 hrs after birth between the G1388A and G1376T G1388A gene mutation groups. The incidence of acute bilirubin encephalopathy, the peak bilirubin concentration 72 hrs after birth and the risk of serum bilirubin >340 micromol/L in the G-6-PD mutation group were not different from the normal group.

CONCLUSIONSG1388A, G1376T and A95G are common G-6-PD gene mutations in Nanning, Guangxi. The false negative results may be received when the NBT method is used for diagnosis of G-6-PD deficiency. There are similar effects on the incidence of acute bilirubin encephalopathy and the peak bilirubin concentration 72 hrs after birth between different gene mutation groups. G-6-PD gene mutations alone may not contribute to the development of acute bilirubin encephalopathy and the changes of peak bilirubin concentration 72 hrs after birth and the risk of serum bilirubin >340 micromol/L.

Bilirubin ; blood ; Encephalitis ; etiology ; Female ; Genotype ; Glucosephosphate Dehydrogenase ; genetics ; metabolism ; Glucosephosphate Dehydrogenase Deficiency ; genetics ; Humans ; Infant, Newborn ; Jaundice, Neonatal ; blood ; genetics ; Male ; Mutation

OBJECTIVE: To explore the genetic etiology and differential diagnosis for a patient with jaundice. METHODS: Clinical data of the patient and his parents were collected. Genes associated with metabolic liver diseases were subjected to high-throughput sequencing. The pathogenicity of the candidate variants was predicted by using bioinformatics software. RESULTS: High-throughput sequencing revealed that the proband has harbored two variants of the ABCC2 gene (NM_000392) including c.3011C>T (p.T1004I) and c.3541C>T (p.R1181X), which were respectively inherited from his father and mother. Both variants have been previously unreported and predicted to be pathogenic by bioinformatics analysis. CONCLUSION The proband was diagnosed with Dubin-Johnson syndrome due to the compound heterozygous variants of the ABCC2 gene. Genetic testing has enabled accurate differential diagnosis of Dubin-Johnson syndrome in this patient.
Genetic Testing ; High-Throughput Nucleotide Sequencing ; Humans ; Jaundice, Chronic Idiopathic/pathology* ; Multidrug Resistance-Associated Protein 2 ; Multidrug Resistance-Associated Proteins/genetics* ; Mutation