进行性家族性肝内胆汁淤积3型1例报告

<正>进行性家族性肝内胆汁淤积症(progressive familial intrahepatic cholestasis,PFIC)是常染色体隐性遗传性胆汁淤积性肝病,主要由基因突变后所致胆汁分泌或排泄障碍,随着病情的发展,最后可进展为肝纤维化、肝硬化、肝衰竭^[1]。根据基因突变不同,PFIC目前分为6种亚型,分别由ATP8B1、ABCB11、ABCB4、TJP2、NR1H4和MYO5B基因突变导致^[2],现将四川省人民医院消化为科收治的1例表现为肝内胆汁淤积的患者,经基因检测、肝组织活检、影像学等证实为PFIC3型患者的临床资料报道如下。     

ABCB11缺陷病

遗传性婴儿胆汁淤积症是儿童期肝病死亡或致残的重要原因.随着分子医学的发展,ABCB11缺陷病等一系列遗传因素引起的婴儿肝内胆汁淤积症被发现和认识.ABCB11缺陷可引起几种临床表现不同的胆汁淤积,包括进行性家族性肝内胆汁淤积症2型(PFIC2)、良性复发性肝内胆汁淤积症2型(BRIC2)、妊娠期肝内胆汁淤积症(ICP2)以及药物性胆汁淤积症(DIC).     

进行性家族性肝内胆汁淤积症的研究现状

进行性家族性肝内胆汁淤积症(PFIC)是一组罕见的异质性常染色体隐性遗传性疾病,发病率约为1/50 000~1/100 000。依据编码肝细胞膜转运蛋白基因的不同,可将PFIC分为三型。PFIC-1、PFIC-2和PFIC-3分别是ATP8B1、ABCB11和ABCB4基因突变所致。PFIC-1和PFIC-2血清GGT活性正常,而PFIC-3血清GGT活性升高。PFIC以严重肝内胆汁淤积为主要特征,在婴儿或者儿童期发病,进展迅速,通常在儿童或者青春期进展为终末期肝病。诊断主要靠临床症状、生化学检测、肝脏影像学、肝脏病理学及基因检测等。熊去氧胆酸是所有类型PFIC患者的初始治疗药物,外科胆汁分流术能减轻部分PFIC-1或PFIC-2患者瘙痒症状,延缓病情进展,但对大多数患者肝移植是唯一有效的治疗措施。     

进行性家族性肝内胆汁淤积症的最新研究进展

进行性家族性肝内胆汁淤积症（PFIC）是一组异质性的常染色体隐性遗传病。依特异性肝细胞转运基因突变的不同,PFlC分为3型。PFIC-1型是ATPSB1基因突变所致,PFIC-2型是ABCB11基因突变所致,PFIC-3型是ABCB4基因突变所致。胆汁淤积是PFIC的主要临床征象。PFIC-1和PFIC-2血清γ谷氨酰转肽酶（γ-GT）活性正常,而PFIC=3患者血清γ-GT活性升高。熊去氧胆酸是所有类型PFIC患儿的初始治疗选择,外科胭汁分流术能减轻部分PFIC-1或PFIC-2患者瘙痒,延缓病情进展,但对大多数患者肝移植乃惟一有效治疗措施。     

进行性家族性肝内胆汁淤积症3型

进行性家族性肝内胆汁淤积症3型(progressive familial intrahepatic cholestasis type 3,PFIC3)是一种常染色体隐性遗传性疾病,由编码多药耐药蛋白3(multidrug resistance protein 3,MDR3)的AB CB4(ATP-bindingcassette,sub-family B,member 4)基因突变引起~([1]).PFIC3临床上可表现为反复瘙痒、黄疸、白陶土样便、肝脾肿大及胃肠道出血等,常在成年前进展为肝硬化和肝衰竭~([1-3]).PFIC3是进行性家族性肝内胆汁淤积症的一种亚型,与进行性家族性肝内胆汁淤积症1型和2型的主要区别在于血清γ-谷氨酰转肽酶(GGT)升高及肝组织病理表现为明显的小胆管增生~([4]).     

MYO5B缺陷可导致全谱系低GGT胆汁淤积症

<正>【据《Hepatology》2017年3月报道】题:MYO5B缺陷可导致全谱系低GGT胆汁淤积症(作者王建设等)低GGT胆汁淤积症常提示存在遗传基因缺陷。以往已经鉴定到数个导致遗传性婴儿及儿童低GGT胆汁淤积症的致病基因,如ATP8B1基因和ABCB11基因,均可导致从良性复发性肝内胆汁淤积症(BRIC)到进行性家族性肝内胆汁淤积症(PFIC)的谱系表型。然而,仍有大约1/3~1/4的低GGT胆汁淤积症患儿无法检测到已知致病基因突变,提示可能存在其他尚未发现的新致病基因。来自复旦大学附属儿科医院、复旦大学附属金山医院的王建设等收集无反复腹泻或肠外营养史、不明原因、单纯表现为低     

ATP8B1缺陷病

进行性家族性肝内胆汁淤积症( progressive familial intrahepatie cholestasis,PFIC)是一组常染色体隐性遗传病,以肝内胆汁淤积为主要表现,通常在婴儿或儿童期起病,最终进展至肝功能衰竭.根据致病基因不同,PFIC主要分为3型,即PFIC1、PFIC2、PFIC3.其中PFIC1由ATP8B1基因突变引起,以持续性肝内胆汁淤积、黄疸伴瘙痒为特征,通常在1岁之前发病,随着病情的进展,最终发展为肝纤维化、肝硬化和肝功能衰竭.此外,ATP8B1基因突变还可导致良性再发型肝内胆汁淤积症(benign recurrent intrahepatic cholestasis,BRIC)1型和妊娠期肝内胆汁淤积1型(intrahepatic cholestasis of pregnancy,ICP)1型.因此,PFIC1、BRIC1及ICP1共同构成了ATP8B1缺陷病的临床疾病谱.     

进行性家族性肝内胆汁淤积症3型一家系2例报告

正进行性家族性肝内胆汁淤积症(progressive familial intrahepatic cholestasis,PFIC)是一组婴儿或儿童期起病,以严重肝内胆汁淤积及皮肤瘙痒为主要特征,在儿童期或者青春期可因肝衰竭而导致死亡的罕见常染色体隐性遗传性疾病。目前确切发病率尚无报道,估计为1/50 000～1/100 000[1]。PFIC共分6型,是我国儿童慢性胆汁淤积的重要原因之一。其中,1、2、4、5、6型的血清Y-GGT特征性降低或正常,而由ABCB4基因突     

ATP结合盒亚家族B成员4(ABCB4)基因突变相关性肝硬化合并胆囊结石1例报告

ATP结合盒亚家族B成员4(ABCB4)基因突变疾病谱涉及进行性家族性肝内胆汁淤积3型、胆石症、妊娠期肝内胆汁淤积症、门静脉高压、肝硬化,甚至原发性肝脏、胆道恶性肿瘤等多种疾病。本院肝胆内科收治1例青年男性患者,入院初步诊断为胆囊结石,计划腹腔镜胆囊切除术,术前检查发现该患者肝功能异常、肝硬化、脾大、食管静脉轻度曲张,后进一步行二代测序明确诊断为ABCB4基因突变相关性肝硬化合并胆囊结石,给予熊去氧胆酸胶囊利胆治疗后,肝功能逐渐恢复正常。     

进行性家族性肝内胆汁淤积

进行性家族性肝内胆汁淤积(PFIC)是一组常染色体隐性遗传肝细胞源性儿童胆汁淤积症。根据病因可以分为3型：1型源于ATP8B1基因的突变,2型源于ABCB11基因的突变,3型源于MDR3基因的突变。临床以有胆汁淤积以及严重的皮肤瘙痒为特征。治疗方法包括药物治疗、外科部分胆道外分流术和肝移植三种方法。     

ABCB11 gene mutations in Chinese children with progressive intrahepatic cholestasis and low γ glutamyltransferase

Background: Progressive familial intrahepatic cholestasis type 2 (PFIC2) is a severe autosomal recessive liver disorder of childhood that can cause cholestasis and progress to end‐stage liver disease. ABCB11 gene mutations causing PFIC2 have been reported in some population groups, but not in mainland Chinese. Aims: To elucidate the existence of and characterize ABCB11 gene mutations in mainland Chinese with progressive intrahepatic cholestasis and low γ glutamyltransferase (GGT). Methods: Twenty‐four children presenting with progressive intrahepatic cholestasis and low GGT were admitted to a tertiary paediatric hospital in eastern China from January 2004 to July 2007. All encoding exons and flanking areas of the ABCB11 gene were sequenced. Hepatic histopathology results were obtained by review of the medical record. Results: Twelve novel mutations of ABCB11 gene were found in seven patients: three nonsense mutations, six missense mutations, two splicing mutations and one intronic mutation. Giant cell transformation of hepatocytes was demonstrated in all the four patients with ABCB11 mutations and four of 12 patients without mutations in coding sequences of ABCB11 gene who received liver needle biopsy. Conclusions: ABCB11 gene mutations play an important role in Chinese patients with progressive intrahepatic cholestasis and low GGT. The characteristics of ABCB11 gene mutations in Chinese are different from other population groups. Histological examination may be helpful in diagnosis of PFIC2.     

Bile salt export pump deficiency disease: two novel,late onset,ABCB11 mutations identified by next generation sequencing

Progressive familial intrahepatic cholestasis (PFIC) is a heterogeneous group of autosomal recessive cholestatic diseases of childhood and represents the main indication for liver transplantation at this age; PFIC2 involves ABCB11 gene, that encodes the ATP-dependent canalicular bile salt export pump (BSEP). Benign intrahepatic cholestasis (BRIC) identifies a group of diseases involving the same genes and characterized by intermittent attacks of cholestasis with no progression to liver cirrhosis. Diagnosis with standard sequencing techniques is expensive and available only at a few tertiary centers. We report the application of next generation sequencing (NGS) in the diagnosis of the familial intrahepatic cholestasis with a parallel sequencing of three causative genes. We identified the molecular defects in ABCB11 gene in two different probands who developed a severe cholestatic disease of unknown origin. In the first patient a compound heterozygosity for the novel frameshift mutation p.Ser1100GlnfsX38 and the missense variant p.Glu135Lys was detected. In the second patient, triggered by contraceptive therapy, we identified homozygosity for a novel mis-sense variant p.Ala523Gly. In conclusion, these mutations seem to have a late onset and a less aggressive clinical impact, acting as an intermediate form between BRIC and PFIC.     

Prenatal diagnosis of progressive familial intrahepatic cholestasis type 2

Background and Aim:  Progressive familial intrahepatic cholestasis type 2 (PFIC2) results from genetic defects of the hepatobiliary bile salt export pump (BSEP, ABCB11 ) at chromosome 2q24. Patients with progressive cholestasis and liver cirrhosis usually need liver transplantation in the first decade. Mutations in ABCB11 are also associated with benign recurrent intrahepatic cholestasis type 2 and intrahepatic cholestasis of pregnancy in adult patients. We aimed to make the prenatal diagnosis of PFIC2.
Methods:  Genetic diagnosis was performed by genomic DNA analysis. Prenatal genetic diagnosis was made by fetal amniotic DNA and chorionic DNA analysis.
Results:  We report on two families of PFIC2 with inherited compound heterozygous mutations of ABCB11 (M183V and R303K in Family 1, V284L and 1145delC in Family 2) from the parents. An infant with heterozygous M183V mutation was later born healthy in Family 1. A fetus with compound heterozygous missense mutation V284L and 1145delC was terminated in Family 2.
Conclusion:  Prenatal diagnosis of PFIC2 was helpful to prevent further affected children in families with this fatal disease.     

Recurrent intrahepatic cholestasis of pregnancy and chain-like choledocholithiasis in a female patient with stop codon in the ABDC4-gene of the hepatobiliary phospholipid transporter

We report the case of a 40-years-old female patient with recurrent cholestatic liver disease who presented twice with severe intrahepatic cholestasis of pregnancy and pronounced choledocholithiasis between pregnancies. Bile duct stones were removed endoscopically and a laparoscopic cholecystectomy was performed after the second pregnancy. Liver histology revealed intrahepatic cholestasis with portal inflammation and fibrosis, resembling progressive familial intrahepatic cholestasis (PFIC). Molecular genetic studies identified the heterozygous mutation c.957C > T in the ABCB4 gene encoding the hepatobiliary phospholipid transporter. This is the first report of this mutation that introduces a stop codon in an index patient with intrahepatic cholestasis of pregnancy and multiple bile duct stones. In addition, we detected the ABCB11 polymorphism V 444A, which is associated with a decreased expression of the bile salt export pump. Whereas homozygous carriers of the ABCB4 mutation develop PFIC type 3, the heterozygous ABC transporter mutations represent genetic risk factors for cholelithiasis and recurrent cholestatic hepatitis upon challenge with oral contraceptives or during pregnancy. Of note, the patient presented with normal serum gamma-glutamyltranspeptidase activities during pregnancy-associated cholestatic episodes but normal liver enzymes after delivery, whereas choledocholithiasis was associated with high gamma-glutamyl transpeptidase levels. It is unknown whether ursodeoxycholic acid prevents cholestasis or gallstones in patients with ABCB4 deficiency.     

Familial intrahepatic cholestasis: New and wide perspectives

BackgroundProgressive familial intrahepatic cholestasis (PFIC) includes autosomal recessive cholestatic rare diseases of childhood.AimsTo update the panel of single genes mutations involved in familial cholestasis.MethodsPubMed search for “familial intrahepatic cholestasis” alone as well as in combination with other key words was performed considering primarily original studies and meta-analyses.ResultsPFIC1 involves ATP8B1 gene encoding for aminophospholipid flippase FIC1. PFIC2 includes ABCB11 gene, encoding for protein functioning as bile salt export pump. PFIC3 is due to mutations of ABCB4 gene responsible for the synthesis of class III multidrug resistance P-glycoprotein flippase. PFIC4 and PFIC5 involve tight junction protein-2 gene and NR1H4 gene encoding for farnesoid X receptor. Benign Intrahepatic Cholestasis, Intrahepatic Cholestasis of Pregnancy and Low-phospholipid-associated cholelithiasis involve the same genes and are characterized by intermittent attacks of cholestasis, no progression to cirrhosis, reversible pregnancy-specific cholestasis and cholelithiasis in young people. Blood and liver tissue levels of bile-excreted drugs can be influenced by the presence of mutations in PFIC genes, causing drug-induced cholestasis. Mutations in PFIC genes might increase the risk of liver cancer.ConclusionThere is a high proportion of unexplained cholestasis potentially caused by specific genetic pathophysiologic pathways. The use of next generation sequencing and whole-exome sequencing could improve the diagnostic process in this setting.     

Newer variants of progressive familial intrahepatic cholestasis

Progressive familial intrahepatic cholestasis (PFIC) is a heterogeneous group of disorders characterized by defects in bile secretion and presentation with intrahepatic cholestasis in infancy or childhood. The most common types include PFIC 1 (deficiency of FIC1 protein, ATP8B1 gene mutation), PFIC 2 (bile salt export pump deficiency, ABCB11 gene mutation), and PFIC 3 (multidrug resistance protein-3 deficiency, ABCB4 gene mutation). Mutational analysis of subjects with normal gamma-glutamyl transferase cholestasis of unknown etiology has led to the identification of newer variants of PFIC, known as PFIC 4, 5, and MYO5B related (sometimes known as PFIC 6). PFIC 4 is caused by the loss of function of tight junction protein 2 (TJP2) and PFIC 5 is due to NR1H4 mutation causing Farnesoid X receptor deficiency. MYO5B gene mutation causes microvillous inclusion disease (MVID) and is also associated with isolated cholestasis. Children with TJP2 related cholestasis (PFIC-4) have a variable spectrum of presentation. Some have a self-limiting disease, while others have progressive liver disease with an increased risk of hepatocellular carcinoma. Hence, frequent surveillance for hepatocellular carcinoma is recommended from infancy. PFIC-5 patients usually have rapidly progressive liver disease with early onset coagulopathy, high alpha-fetoprotein and ultimately require a liver transplant. Subjects with MYO5 B-related disease can present with isolated cholestasis or cholestasis with intractable diarrhea (MVID). These children are at risk of worsening cholestasis post intestinal transplant (IT) for MVID, hence combined intestinal and liver transplant or IT with biliary diversion is preferred. Immunohistochemistry can differentiate most of the variants of PFIC but confirmation requires genetic analysis.     

Benign recurrent intrahepatic cholestasis type 2 is caused by mutations in ABCB11

BACKGROUND & AIMS: Progressive familial intrahepatic cholestasis (PFIC) and benign recurrent intrahepatic cholestasis (BRIC) are hereditary liver disorders; PFIC is characterized by severe progressive liver disease whereas BRIC patients have intermittent attacks of cholestasis without permanent liver damage. Mutations in ATP8B1 are present in PFIC type 1 and in a subset of BRIC patients. We hypothesized that a genetically distinct form of BRIC is associated with mutations in ABCB11. This gene encodes the bile salt export pump (BSEP) and is mutated in PFIC type 2. METHODS: Patients from 20 families were included; all had a normal ATP8B1 sequence. Sequencing of all 27 coding exons including the splice junctions of ABCB11 revealed 8 distinct mutations in 11 patients from 8 different families: one homozygous missense mutation (E297G) previously described in PFIC2 patients, 6 novel missense mutations, and one putative splice site mutation. RESULTS: In 12 families, no mutations in ATB8B1 or ABCB11 were detected. Pancreatitis is a known extrahepatic symptom in BRIC caused by ATP8B1 mutations, but was not present in BRIC patients with mutations in ABCB11. In contrast, cholelithiasis was observed in 7 of 11 BRIC patients with mutations in ABCB11, but has not been described in ATP8B1-affected BRIC patients. CONCLUSIONS: Mutations in ABCB11 are associated with BRIC, and consistent with the genetic classification of PFIC into 2 subtypes, we propose that this disorder be named BRIC type 2.     

Gradual improvement of liver function after administration of ursodeoxycholic acid in an infant with a novel ABCB11 gene mutation with phenotypic continuum between BRIC2 and PFIC2

OBJECT: The authors report the case of a boy with PFIC type 2 or BRIC type 2 who suffered from liver dysfunction at 2 months after birth. METHODS AND RESULTS: A liver biopsy specimen revealed mild liver cirrhosis, and the findings resembled those observed in Byler disease. Genetic examination revealed a normal familial intrahepatic cholestasis-1 gene, but a heterozygous mutation for the ABCB11, C1620A (F540L), was observed. Therefore, the patient was initially diagnosed with PFIC type 2. For 3 years after the diagnosis, he had severe pruritus, an increased serum bile acid, and normal serum values of gamma-glutamyl transaminase. At the age of 2, treatment with administration of ursodeoxycholic acid was started; subsequently, a gradual improvement in his liver function was observed. At the age of 3, he suffered from massive intestinal and pulmonary hemorrhage, which improved immediately after the administration of vitamin K. He was then admitted to our hospital for liver transplantation. At 1 month after the admission, his liver dysfunction showed further improvement, except for a mild increase in the serum bile acid level. This condition did not show any change during the 5-year follow-up period. In addition, the patient showed severe growth failure and was diagnosed with growth hormone deficiency. Hence, he receives growth hormone administration. CONCLUSION: The patient could be genetically diagnosed with bile salt export pump disease of PFIC type 2 or BRIC type 2. Various clinical features are observed in PFIC or BRIC patients with ABCB11 mutation.     

Impaired expression and function of the bile salt export pump due to three novel ABCB11 mutations in intrahepatic cholestasis

BACKGROUND/AIMS: Inherited dysfunction of the bile salt export pump BSEP (ABCB11) causes a progressive and a benign form of familial intrahepatic cholestasis, denominated as PFIC2 and BRIC2, respectively. We functionally characterized novel ABCB11 mutations encountered in two patients with a PFIC2 and a BRIC2 phenotype, respectively. METHODS: BSEP expression was determined in liver biopsies by immunohistochemistry. ABCB11 mutations were functionally characterized by taurocholate transport in SF9 cells transfected with human ABCB11. RESULTS: The PFIC2 patient was compound heterozygous for a splicing mutation in intron 4 ((+3)A > C) combined with an early stop codon at position 930 (R930X), while the BRIC2 patient was compound heterozygous for two nonsynonymous mutations in exon 9 (E297G) and exon 12 (R432T), respectively. Hepatic BSEP expression was absent in PFIC2 and preserved in BRIC2. In BRIC2, taurocholate transport was decreased to 13% and 20% of reference levels for R432T and E297G, respectively. CONCLUSIONS: The intron 4 (+3)A > C, R930X and R432T represent previously undescribed mutations of the ABCB11 gene that confer a PFIC2 and a BRIC2 phenotype, respectively. By combining functional in-vitro characterization with immunohistochemical detection of variant BSEP we provide direct evidence for the role of ABCB11 mutations in the pathogenesis of different forms of intrahepatic cholestasis.     

Novel ABCB11 mutations in a Thai infant with progressive familial intrahepatic cholestasis

Progressive familial intrahepatic cholestasis （PFIC） type 2 is caused by mutations in ABCB11, which encodes bile salt export pump （BSEP）. We report a Thai female infant who presented with progressive cholestatic jaundice since 1 mo of age, with normal serum y-glutamyltransferase. Immunohistochemical staining of the liver did not demonstrate BSEP along the canaliculi, while multidrug resistance protein 3 was expressed adequately. Novel mutations in ABCB11, a four-nucleotide deletion in exon 3, c.90_93delGAAA, and a single-nucleotide insertion in exon 5, c.249_250insT, were identified, with confirmation in her parents. These mutations were predicted to lead to synthesis of truncated forms of BSEP. Immunostaining and mutation analysis thus established the diagnosis of PFIC type