爱华网布加氏综合症是指肝段下腔静脉(IVC)或/和肝静脉(HV)部分或完全阻塞所引起的HV流出道梗阻所引起的症候群。
多普勒超声对布加氏综合症的诊断已得到公认，可明确显示病变的部位、范围、程度，准确反映IVC和HV的血流变化情况，且简便、无痛苦，可重复检查，易于患者接受.，对临床病情分析、术式选择、术中监测、疗效评价有重要的指导意义。
儿童患布加氏综合症的病例很罕见。
遗传
目前发现的致病基因为JAK2 和F5基因。
BUDD-CHIARI SYNDROME
Other entities represented by this entry
Gene map locus: 1q23,9p24
ClinicalSynopsis
TextBack toTop
A number sign (#) is used with this entry because susceptibilityto Budd-Chiari syndrome can result from mutations in the JAK2(147796) orthe F5 (612309) gene.
Clinical FeaturesBack toTop
Budd-Chiari syndrome is a spectrum of disease states, includinganatomic abnormalities and hypercoagulable disorders, resulting inhepatic venous outflow occlusion. Clinical manifestations observedin the majority of patients include hepatomegaly, right upperquadrant pain, and abdominal ascites (Zimmermanet al., 2006).
One of the causes of the Budd-Chiari syndrome is a membranousobstruction of the inferior vena cava (MOVC). Primary thrombosisdue to a thrombophilia such as that resulting from defects in thenatural coagulation inhibitors such as protein C (612283), protein S(176880), andantithrombin III (107300) are alsocauses. Riemens et al. (1995) reported a family in which 3 of 11 sibs(2 sisters and 1 brother) showed symptoms of MOVC developing inearly adult life. All had signs of more longstanding disease, asjudged by the presence of collaterals, cirrhosis, and, in one case,hepatocellular carcinoma. The brother died with lung metastasisfrom the hepatocellular carcinoma, while the 2 sisters had surgicalremoval of the membrane and were well 20 and 21 years aftersurgery. On family screening, no further cases of membranousobstruction of the inferior vena cava were found. There was noevidence of an inherited defect in a coagulation inhibitor orplasminogen deficiency (173350); however,Riemens et al. (1995) could not totally exclude a thromboticetiology.
Budd-Chiari syndrome is a rare but typical complication inpatients with polycythemia vera (PV; 263300). Cario et al. (2003) described a third pediatric case ofBudd-Chiari syndrome as the initial symptom of familialpolycythemia vera in an 11-year-old girl; the patient's grandmotheralso had polycythemia vera. The patient's mother was unaffected.The patient underwent orthotopic liver transplantation and thepolycythemia vera was treated with hydroxyurea. In agreement withthe clinical diagnosis, the polycythemia rubra vera-1 gene (PRV1;162860)showed increased mRNA expression in peripheralgranulocytes.
Menon et al. (2004) reviewed all aspects of Budd-Chiarisyndrome, including the inherited hypercoagulable states that hadbeen found to be associated with the disorder. They noted that therelative risk of hepatic vein thrombosis among women who use oralcontraceptives is 2.37, which is similar to their relative risk ofstroke, myocardial infarction, and venous thromboembolism (Vallaet al., 1986). Many patients in whom Budd-Chiari syndromedevelops in association with the use of oral contraceptives orpregnancy also have an underlying thrombophilia, either inheritedor acquired.
Molecular GeneticsBack toTop
Mahmoud et al. (1997) reported the incidence of the factor VLeiden mutation (R506Q; 612309.0001)in Budd-Chiari syndrome and portal vein thrombosis. The R506Qmutation was seen in 7 (23%) of 30 patients with Budd-Chiarisyndrome (6 heterozygotes and 1 homozygote), 3 of whom hadcoexistent myeloproliferative disease. Only 1 (3%) of 32 patientswith portal vein thrombosis was found to have the R506Q mutation.The mutation was found in 3 (6%) of the 54 controls, who had liverdisease but no history of thrombophilia. Mahmoud et al. (1997) concluded that the R506Q mutation seemsto be an important factor in the pathogenesis of Budd-Chiarisyndrome but not of portal vein thrombosis.
Gurakan et al. (1999) described a child with Budd-Chiarisyndrome who was homozygous for the factor V Leiden mutation.Budd-Chiari syndrome is rare in children.
Janssen et al. (2000) compared 43 patients with Budd-Chiarisyndrome and 92 patients with portal vein thrombosis with 474population-based controls. The relative risk of Budd-Chiarisyndrome was 11.3 for individuals with the factor V Leidenmutation, 2.1 for those with a prothrombin (176930) genemutation, and 6.8 for those with protein C deficiency. In patientswith portal vein thrombosis, the corresponding figures were 2.7,1.4, and 4.6, respectively. The relative risk of Budd-Chiarisyndrome or portal vein thrombosis was not increased in thepresence of inherited protein S or antithrombin deficiency.
Patel (2005) identified a V617F mutation in the JAK2 gene(147796.0001)in a high proportion of patients with the Budd-Chiari syndrome,providing evidence that these patients have a latentmyeloproliferative disorder. Chung et al. (2006) described Budd-Chiari syndrome in a46-year-old woman who was well until the onset of increasingabdominal distention over a period of several days. She was foundto have a combination of the JAK2 V617F mutation and the factor VLeiden mutation.
PathogenesisBack toTop
Sozer et al. (2009) identified somatic homozygous JAK2 V617Fmutations in liver venule endothelial and hematopoietic cells from2 unrelated patients with polycythemia vera who developedBudd-Chiari syndrome. However, analysis of endothelial cells from athird PV patient with Budd-Chiari syndrome and in 2 patients withhepatoportal sclerosis without PV showed only wildtype JAK2.Endothelial and hematopoietic cells are believed to come from acommon progenitor called the hemangioblast. Sozer et al. (2009) concluded that finding V617F-positiveendothelial cells and hematopoietic cells from patients with PV whodeveloped Budd-Chiari syndrome indicates that endothelial cells areinvolved by the PV malignant process, and suggested that thedisease might originate from a common cell of origin in somepatients.
