Concurrence of novel mutations causing Gilbert's and Dubin-Johnson syndrome with poor clinical outcomes in a Han Chinese family.

Dual-hereditary jaundice (Dubin-Johnson syndrome (DJS) and Gilbert's syndrome (GS)) is a rare clinical entity resulting from defects of the ATP binding cassette subfamily C member 2 (ABCC2) and UDP glucuronosyltransferase family 1 member A1 (UGT1A1) genes with autosomal recessive inheritance. In this study, we aimed to investigate the mutation profiles and characterize the phenotypes in a Han Chinese family with DJS and GS. Genetic screening for variants in the ABCC2 and UGT1A1, immunohistochemistry for expression of ABCC2, and histopathological examination were carried out. The proband and his brother had unconjugated and conjugated hyperbilirubinemia after birth. The proband's sister had only conjugated hyperbilirubinemia after birth. The proband developed into pleural effusions and ascites, pericardial thickening, intrahepatic and extrahepatic biliary duct dilatation, and enlarged gallbladder at age 50. Hepatocellular carcinoma occurred in the proband's brother at age 46. Seven compound defects of the ABCC2 gene [c.2414delG, p.(Ile1489Gly), p.(Thr1490Pro), and p.(Ile1491Gln)] and the UGT1A1 gene (c.-3279T>G, p.(Gly71Arg), and p.(Pro451Leu)) were identified in family members. Accumulation of pigment in hepatocytes characteristic of that in DJS was present in the proband and his brother. Expression of ABCC2 protein was markedly diminished in the patient's liver. Our results show a different genetic profile of DJS and GS in a Han Chinese family, indicating a more complex pattern of dual-hereditary jaundice among different populations. The present study illuminates the underpinnings of DJS and GS and extends the mutation profiles and phenotypes of these two syndromes in dual-hereditary jaundice.

Genotype-Phenotype Association in ABCC2 Exon 18 Missense Mutation Leading to Dubin-Johnson Syndrome: A Case Report.

We report a case of a patient with Dubin-Johnson syndrome confirmed by a genetic study. A 50-year-old woman who had symptoms of intermittent right upper quadrant abdominal pain was diagnosed with calculous cholecystitis at another institute and was presented to our hospital for a cholecystectomy. She had no history of liver disease, and her physical examination was normal. Abdominal computed tomography showed a gallbladder stone with chronic cholecystitis. During a laparoscopic cholecystectomy for cholecystitis, a smooth, black-colored liver was noted, and a liver biopsy was performed. The biopsy specimen showed coarse, dark brown granules in centrilobular hepatocytes via hematoxylin and eosin staining. We performed a genetic study using the blood samples of the patient. In the adenosine triphosphate-binding cassette subfamily C member 2 (ABCC2) mutation study, a missense mutation in exon 18 was noted. Based on the black-colored liver without nodularity, conjugated hyperbilirubinemia, the liver biopsy results of the coarse pigment in centrilobular hepatocytes, and the ABCC2 mutation, Dubin-Johnson syndrome was diagnosed. The patient was managed with conservative care using hepatotonics. One month after follow-up, total bilirubin and direct bilirubin remained in a similar range. Another follow-up was planned a month later, and the patient maintained her use of hepatotonics.

[Genetic analysis of a case with Dubin-Johnson syndrome due to two novel variants of ABCC2 gene].

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.

A case of true vocal fold jaundice.

OBJECTIVES: While jaundice is frequently described in the sclera and skin, there are few reports of true vocal fold jaundice in patients with high bilirubin, and no reports by otolaryngologists in the literature. Here we describe a case of a patient with bilateral true vocal fold jaundice and discuss the potential pathogenesis and implications of this finding. METHODS: A 29-year-old man with history of Dubin-Johnson Syndrome presented with cough and difficulty breathing and was incidentally found to have persistent yellow discoloration of the true vocal folds bilaterally. RESULTS: Videolaryngoscopic exam demonstrated bilateral true vocal fold yellow discoloration with sparing of nearby laryngeal structures on initial presentation and follow-up exam. Direct and total bilirubin levels were found to be elevated. CONCLUSION: A patient with benign Dubin-Johnson Syndrome and elevated total and direct bilirubin was incidentally found to have bilateral vocal fold jaundice. Jaundice and the presence of bilirubin do not appear to cause harm to the function or health of the true vocal folds and may be related to the high concentration of elastin present in the true vocal folds.

Clinical characteristics and liver profiles of Dubin-Johnson syndrome in neonates: Multicenter retrospective study.

OBJECTIVES: Dubin-Johnson syndrome (DJS) is a rare benign autosomal recessive disorder characterized by cholestasis in neonates. The aim of the present study was to describe the clinical characteristics, hepatic profiles, histopathology, gene mutations, and treatment outcomes of neonatal DJS. MATERIAL AND METHODS: A multicenter retrospective study was undertaken with patients who had DJS. The authors identified DJS in neonates and reviewed medical records for details. The diagnosis of DJS was based on the presence of unexplained prolonged conjugated hyperbilirubinemia and presence of a mutation in the ATP Binding Cassette Subfamily C Member 2 (ABCC2) gene detected in genomic DNA extracted from circulating blood cells. RESULTS: Eleven children with DJS were identified in the study. The study population comprised eight males and three females. The median age at presentation was 21 days. Dysmorphic features were not recorded in any of the patients. Cholestasis, high serum bile acids, and normal transaminase levels were found in all patients (100%). Serum alkaline phosphatase and gamma glutamyl transferase were elevated in four patients (36%). Hypoalbuminemia and coagulopathy were not noted in these patients. Consanguinity was present in nine patients (82%). All patients had normal abdominal ultrasound findings. Genetic molecular testing showed that 82% of the patients reported a pathogenic variant of the ABCC2 gene defect with the same variant c.2273G>T (Gly 758 val) chromosome 10. All patients were alive without liver transplantation. CONCLUSIONS: This is the largest study worldwide describing that neonatal DJS is a benign cholestatic disease with favorable outcomes. Low-grade direct hyperbilirubinemia, normal transaminases, and elevated serum bile acids are the main characteristic findings of DJS.

A Case of Dubin-Johnson Syndrome Presenting as Neonatal Cholestasis With Paucity of Interlobular Bile Ducts.

Dubin-Johnson syndrome (DJS) is a rare autosomal recessive disorder that typically manifests in young adulthood as jaundice with conjugated hyperbilirubinemia. We report a case presenting as neonatal cholestasis with the unexpected histologic finding of paucity of interlobular bile ducts, a feature that is not typically seen in DJS. The diagnosis was confirmed by absent canalicular multidrug-resistance-associated protein 2 (MRP2) immunohistochemical staining on liver biopsy tissue and molecular genetic testing that demonstrated heterozygous mutations in the ATP-Binding Cassette Subfamily C Member 2 (ABCC2) gene, including a novel missense mutation. This report describes a case of DJS with atypical clinicopathologic findings and suggests that DJS should be considered in patients with neonatal cholestasis and bile duct paucity.

Clinical, Pathologic, and Genetic Features of Neonatal Dubin-Johnson Syndrome: A Multicenter Study in Japan.

OBJECTIVE: To clarify the clinical, pathologic, and genetic features of neonatal Dubin-Johnson syndrome. STUDY DESIGN: Ten patients with neonatal Dubin-Johnson syndrome were recruited from 6 pediatric centers in Japan between September 2013 and October 2016. Clinical and laboratory course, macroscopic and microscopic liver findings, and molecular genetic findings concerning ATP-binding cassette subfamily C member 2 (ABCC2) were retrospectively and prospectively examined. RESULTS: All neonates exhibited cholestasis, evident as prolonged jaundice with or without acholic stools and elevations of serum direct bilirubin as well as γ-glutamyltransferase or total bile acids. Only 38% (3 of 8) of patients who underwent liver biopsy showed a grossly black liver or melanin-like pigment deposits in hepatocytes; their biopsies were performed in early infancy. Immunohistochemically, all liver specimens showed no expression of multidrug resistance-associated protein 2 but increased expression of the bile salt export pump protein. Homozygous or compound heterozygous pathogenic variants of ABCC2 were identified in all patients, representing 11 distinct pathogenic variants including 2 not previously reported. CONCLUSIONS: Immunohistochemical staining of the liver for multidrug resistance-associated protein 2 and molecular genetic analysis of ABCC2 are crucial for accurate diagnosis of neonatal Dubin-Johnson syndrome.

Severe jaundice due to coexistence of Dubin-Johnson syndrome and hereditary spherocytosis: a case report.

Dubin-Johnson syndrome is a chronic, benign, intermittent jaundice, mostly of conjugated hyperbilirubinemia. The level of bilirubin is not expected to be more than 20 mg/dl in this syndrome. In this article, we report a patient who was evaluated for hyperbilirubinemia and liver function test abnormalities and diagnosed with Dubin-Johnson syndrome coexisting with hereditary spherocytosis. We suggest that other diseases should be investigated if patients with Dubin-Johnson syndrome present with severe hyperbilirubinemia. Dubin-Johnson syndrome accompanied by hemolytic diseases might also have high coproporphyrin levels (as in Rotor's syndrome) than expected in pure Dubin-Johnson syndrome.

[Pleomorphism of the myelin-like bodies in the hepatocytes of patients with Dubin-Johnson syndrome complicated with chronic hepatitis B].

OBJECTIVE: To explore characteristics of the myelin-like bodies in the hepatocytes of patients with Dubin-Johnson syndrome (DJS) complicated with chronic hepatitis B (CHB). METHODS: 11 cases of DJS complicated with CHB and 5 cases DJS without CHB were studied clinicopathologically. The hepatocyte ultrastructure was observed with transmission electron microscope and taken photos. The data were compared and analyzed using Fisher's Exact Test. RESULTS: Deposition of myelin-like bodies can be observed in the hepatocytes of DJS patients with CHB but can not in DJS patients without CHB. The morphology of pigment varys. The electron density and volume of pigment in DJS patients with CHB can be classified into five types: brights (2/11,18.2%), reticulation (1/11, 9.1%), punctiform (6/11, 54.5%), abnormity (1/11, 9.1%) and primary type (1/11, 9.1%). The myelin-like bodies in the hepatocytes of patients with DJS are high density and round with membrance (we named it as primary type) (5/5, 100%). CONCLUSIONS: The myelin-like bodies in the hepatocytes of DJS patients with CHB possess special pleomorphism and may have important diagnostic value.

Role of Multidrug-Resistance Protein 2 in coproporphyrin transport: results from experimental studies in bile fistula rat models.

Coproporphyrin (CP) is one of the main by-products of heme biosynthesis and its abnormal accumulation is associated with different forms of porphyria. Indirect data obtained from animal and human models have suggested a possible role for Multidrug Resistance-associated Protein 2 (MRP2) and other MRPs in hepatocyte excretion of CP. Using normal, MRP2-deficient and a cholestatic rat model, we have assessed the role of MRPs in CP disposition. MRP levels were assayed using immunofluorescence. Biliary and urinary excretion patterns of CP and conjugate bilirubin were measured during equimolar infusions of CP isomers with and without phenoldibromopthalein sulfonate (BSP), a well-known MRP2 substrate. Our results suggest a role for the MRP system as a possible regulator of CP traffic and accumulation in normal and pathological conditions. Alteration in this systems (as observed in cholestatic disease) may play an important role in triggering clinical expression of porphyria in individuals with underlying mutations leading to porphyrin accumulation and may help explain the phenotypic heterogeneity in patients affected by different forms of porphyrias.

Dubin-Johnson syndrome.

A young man presented with recurrent episodes of mild jaundice. Apart from conjugated hyperbilirubinemia, other liver function tests were always normal. Clinical suspicion of Dubin-Johnson syndrome was raised. Liver biopsy showed diffuse deposition of coarse granular dark brown pigment in hepatocytes. Dubin-Johnson syndrome is a benign condition, which results from a hereditary defect in biliary secretion of bilirubin pigments, and manifests as recurrent jaundice with conjugated hyperbilirubinemia. The defect is due to the absence of the canalicular protein MRP2 located on chromosomes 10q 24, which is responsible for the transport of biliary glucuronides and related organic anions into bile. No treatment is necessary and patients have a normal life expectancy.

Dubin-Johnson syndrome--a clinicopathologic study of twenty cases.

Dubin-Johnson syndrome (DJS) is a rare benign chronic disorder of bilirubin metabolism, characterized by conjugated hyperbilirubinemia, darkly pigmented liver and presence of abnormal pigment in hepatic parenchymal cells. This is a retrospective study of twenty cases of DJS highlighting their major clinical and pathological findings. Liver biopsies were available in all the cases, obtained during a fourteen-year period (January 1991 to March 2005). The patients' age ranged from 7-63 years (median 21 years). These twenty cases comprised 13 males and 7 females. Major clinical manifestations were recurrent or persistent jaundice, abdominal pain and fever. Duration of illness ranged from 9 months to 58 years (median 10 years). All of them had conjugated hyberbilirubinemia and total serum bilirubin levels ranged between 1.4-13 mg/dl (mean 4.4 mg/dl). Liver biopsies revealed presence of coarse granular brown pigment in the cytoplasm of hepatocytes more concentrated in the pericanalicular region and more prominent in centrilobular hepatocytes. Associated findings were presence of hepatitis B virus related chronic hepatitis (1), history of tubercular lymphadenitis (1), chronic cholecystitis in (2), coronary heart disease (1) and exacerbation during pregnancy (1).

Dubin-Johnson syndrome with systemic lupus erythematosus: a case report.

BACKGROUND: Dubin-Johnson syndrome (DJS) is a rare clinical entity. We describe a case of DJS complicated by systemic lupus erythematosus (SLE). METHODS: A case of congenital hyperbilirubinemia with SLE was evaluated systematically including review of history, physical examination for the stigmata of chronic liver disease, and other investigations. RESULT: Liver biopsy revealed a black liver with preserved architecture suggestive of DJS. CONCLUSIONS: SLE may develop in DJS. The relationship between DJS and SLE in this case is most likely a chance occurrence.

Ultrastructure of Kupffer cells and hepatocytes in the Dubin-Johnson syndrome: a case report.

Ultrastructure of Kupffer cells and hepatocytes in liver bioptate was evaluated in a 17-year-old boy with Dubin-Johnson syndrome (DJS). The liver tissue obtained by needle biopsy was fixed in glutaraldehyde and paraformaldehyde and routinely processed for electron microscopic analysis. The ultrastructural examinations of liver bioptate revealed the accumulation of membrane-bound, electron-dense lysosomal granules within the cytoplasm of hepatocytes, characteristic of DJS. They were located mainly in the vicinity of the biliary pole, and preferentially in the centrilobular region that corresponded to the pigment deposits seen under light microscope. The presence of the granules was accompanied by dilated elements of the granular endoplasmic reticulum and paracrystalline mitochondrial inclusions as well as dilation of the bile canaliculi. The changes in hepatocytes co-existed with marked stimulation and enhanced phagocytic activity of Kupffer cells. This was manifested in the accumulation of pigment deposits within their cytoplasm that corresponded to those observed in hepatocytes. Hyperactive pericentral Kupffer cells which are involved in the response to pigmentary material originating from disintegrated hepatocytes may play an essential role in the development of DJS.

Dual hereditary jaundice: simultaneous occurrence of mutations causing Gilbert's and Dubin-Johnson syndrome.

BACKGROUND & AIMS: Dubin-Johnson syndrome is recessively inherited, conjugated hyperbilirubinemia induced by mutations in the ABCC2/MRP2 gene encoding the canalicular transporter for conjugated bilirubin. Gilbert's syndrome is recessively inherited, unconjugated hyperbilirubinemia caused by decreased conjugation rate of bilirubin associated mostly with homozygous A(TA) 7 TAA variant of the TATAA-box in the UGT1A1 gene promoter. Our aim was to establish the molecular diagnosis in a 3-year-old male with atypical, intermittent, predominantly unconjugated, hyperbilirubinemia. METHODS: 99m Tc-HIDA cholescintigraphy was used for imaging the biliary tree. Expression of ABCC2/MRP2 protein in hepatocytes was investigated immunohistochemically. UGT1A1 and ABCC2/MRP2 genes were sequenced from genomic DNA, and the mutations were verified by fragment analysis, sequencing the cloned exons, and restriction fragment length polymorphism. RESULTS: Cholescintigraphy revealed delayed visualization of the gallbladder. A brown granular lipopigment differing from melanin-like pigment reported in Dubin-Johnson syndrome was present in hepatocytes, but, otherwise, liver histology was normal. ABCC2/MRP2 protein was not detected on the canalicular membrane of hepatocytes, and 2 novel mutations were found in the ABCC2/MRP2 gene: a heterozygous in-frame insertion-deletion mutation 1256insCT/delAAACAGTGAACCTGATG in exon 10 inherited from the father and a heterozygous deletion 4292delCA in exon 30 inherited from the mother. In addition, the patient was homozygous for -3279T>G and A(TA) 7 TAA mutations in the UGT1A1 gene promoter. CONCLUSIONS: Our patient represents a case of digenic mixed hyperbilirubinemia-a distinct type of constitutive jaundice resulting from coinherited defects in ABCC2/MRP2 and UGT1A1 genes.

Association of Dubin-Johnson syndrome and portal vein thrombosis.

Dubin-Johnson syndrome is neither complicated by liver cell necrosis nor associated with portal hypertension. We report a 22-year-old man who had recurrent episodes of jaundice (conjugated hyperbilirubinemia) because of Dubin-Johnson syndrome and portal hypertension secondary to portal vein thrombosis. The relationship between Dubin-Johnson syndrome and portal vein thrombosis in this case is most likely a chance occurrence.

A new mutation of the ATP-binding cassette, sub-family C, member 2 (ABCC2) gene in a Japanese patient with Dubin-Johnson syndrome.

Dubin-Johnson syndrome (DJS) is an inherited disorder characterized by conjugated hyperbilirubinemia and is caused by mutations of the canalicular multispecific organic anion transporter (cMOAT)/ multidrug resistance protein 2 (MRP2)/ ATP-binding cassette, sub-family C, member 2 (ABCC2) gene. The ABCC2 protein is located in the apical membrane of hepatocytes, and known mutations of this gene cause impaired maturation and trafficking of the mutated protein from the endoplasmic reticulum (ER) to the Golgi complex. We have characterized the ABCC2 gene in a Japanese DJS patient by polymerase chain reaction and DNA sequencing, resulting in the identification of two mutations. One mutation, 1815+2 (T>A) in the splice donor site of intron 13, has already been reported. However, we have identified a novel nonsense mutation consisting of a (C>T) transition at nucleotide 3928 in exon 28.