Variable morbidity in alagille syndrome: a review of 43 cases

Diseases of bile duct in children

Several diseases originate from bile duct pathology. Despite studies on these diseases, certain etiologies of some of them still cannot be concluded. The most common disease of the bile duct in newborns is biliary atresia, whose prognosis varies according to the age of surgical correction. Other diseases such as Alagille syndrome, inspissated bile duct syndrome, and choledochal cysts are also time-sensitive because they can cause severe liver damage due to obstruction. The majority of these diseases present with cholestatic jaundice in the newborn or infant period, which is quite difficult to differentiate regarding clinical acumen and initial investigations. Intraoperative cholangiography is potentially necessary to make an accurate diagnosis, and further treatment will be performed synchronously or planned as findings suggest. This article provides a concise review of bile duct diseases, with interesting cases.

Diagnosis and management of Alagille and progressive familial intrahepatic cholestasis

Alagille syndrome and progressive familial intrahepatic cholestasis are conditions that can affect multiple organs. Advancements in molecular testing have aided in the diagnosis of both. The impairment of normal bile flow and secretion leads to the various hepatic manifestations of these diseases. Medical management of Alagille syndrome and progressive familial intrahepatic cholestasis remains mostly targeted on supportive care focusing on quality of life, cholestasis, and fat-soluble vitamin deficiency. The most difficult therapeutic issue is typically related to pruritus, which can be managed by various medications such as ursodeoxycholic acid, rifampin, cholestyramine, and antihistamines. Surgical operations were previously used to disrupt enterohepatic recirculation, but recent medical advancements in the use of ileal bile acid transport inhibitors have shown great efficacy for the treatment of pruritus in both Alagille syndrome and progressive familial intrahepatic cholestasis.

Management of adults with Alagille syndrome

Alagille syndrome (ALGS) is a complex rare genetic disorder that involves multiple organ systems and is historically regarded as a disease of childhood. Since it is inherited in an autosomal dominant manner in 40% of patients, it carries many implications for genetic counselling of patients and screening of family members. In addition, the considerable variable expression and absence of a clear genotype-phenotype correlation, results in a diverse range of clinical manifestations, even in affected individuals within the same family. With recent therapeutic advancements in cholestasis treatment and the improved survival rates with liver transplantation (LT), many patients with ALGS survive into adulthood. Although LT is curative for liver disease secondary to ALGS, complications secondary to extrahepatic involvement remain problematic lifelong. This review is aimed at providing a comprehensive review of ALGS to adult clinicians who will take over the medical care of these patients following transition, with particular focus on certain aspects of the condition that require lifelong surveillance. We also provide a diagnostic framework for adult patients with suspected ALGS and highlight key aspects to consider when determining eligibility for LT in patients with this syndrome.

Clinical and Genetic Characteristics of Alagille Syndrome in Adults

BACKGROUND AND AIMS

Alagille syndrome (AGS) is an autosomal dominant multisystem disorder caused by mutations in the JAG1 and NOTCH2 genes. AGS has been rarely reported in adult patients, mainly because its characteristics in adults are subtle. The study aimed to improve the understanding of adult AGS by a descriptive case series.

METHODS

Eight adults diagnosed with AGS at our hospital between June 2016 and June 2019 were included in the study. Clinical data, biochemical results, imaging results, liver histopathology, and genetic testing were analyzed.

RESULTS

Three female and five male patients with a median age of 24.5 years at the time of diagnosis were included in the analysis. The clinical manifestations were adult-onset (62.5%, 5/8), cholestasis (50%, 4/8), butterfly vertebrae (62.5%, 5/8), systolic murmurs (12.5%, 1/8), typical facies (12.5%, 1/8), posterior embryotoxon, and renal abnormalities (0/8). Genetic sequencing showed that all patients had mutations, with four occurring in the JAG1 gene and four in the NOTCH2 gene. Six were substitution mutations, one was a deletion mutation, and one was a splicing mutation. Five had been previously reported; but the others, one JAG1 mutation and two NOTCH2 mutations were unique and are reported here for the first time.

CONCLUSIONS

The clinical manifestations highlighted by the current diagnostic criteria for most adults with AGS are atypical. Those who do not meet the criteria but are highly suspicious of having AGS need further evaluation, especially genetic testing.

Natural history of liver disease in a large international cohort of children with Alagille syndrome: Results from the GALA study

BACKGROUND AND AIMS

Alagille syndrome (ALGS) is a multisystem disorder, characterized by cholestasis. Existing outcome data are largely derived from tertiary centers, and real-world data are lacking. This study aimed to elucidate the natural history of liver disease in a contemporary, international cohort of children with ALGS.

APPROACH AND RESULTS

This was a multicenter retrospective study of children with a clinically and/or genetically confirmed ALGS diagnosis, born between January 1997 and August 2019. Native liver survival (NLS) and event-free survival rates were assessed. Cox models were constructed to identify early biochemical predictors of clinically evident portal hypertension (CEPH) and NLS. In total, 1433 children (57% male) from 67 centers in 29 countries were included. The 10 and 18-year NLS rates were 54.4% and 40.3%. By 10 and 18 years, 51.5% and 66.0% of children with ALGS experienced ≥1 adverse liver-related event (CEPH, transplant, or death). Children (>6 and ≤12 months) with median total bilirubin (TB) levels between ≥5.0 and <10.0 mg/dl had a 4.1-fold (95% confidence interval [CI], 1.6-10.8), and those ≥10.0 mg/dl had an 8.0-fold (95% CI, 3.4-18.4) increased risk of developing CEPH compared with those <5.0 mg/dl. Median TB levels between ≥5.0 and <10.0 mg/dl and >10.0 mg/dl were associated with a 4.8 (95% CI, 2.4-9.7) and 15.6 (95% CI, 8.7-28.2) increased risk of transplantation relative to <5.0 mg/dl. Median TB <5.0 mg/dl were associated with higher NLS rates relative to ≥5.0 mg/dl, with 79% reaching adulthood with native liver ( p < 0.001).

CONCLUSIONS

In this large international cohort of ALGS, only 40.3% of children reach adulthood with their native liver. A TB <5.0 mg/dl between 6 and 12 months of age is associated with better hepatic outcomes. These thresholds provide clinicians with an objective tool to assist with clinical decision-making and in the evaluation of therapies.

Sex differences and risk factors for bleeding in Alagille syndrome

Spontaneous bleeds are a leading cause of death in the pediatric JAG1-related liver disease Alagille syndrome (ALGS). We asked whether there are sex differences in bleeding events in patients, whether Jag1Ndr/Ndr mice display bleeds or vascular defects, and whether discovered vascular pathology can be confirmed in patients non-invasively. We performed a systematic review of patients with ALGS and vascular events following PRISMA guidelines, in the context of patient sex, and found significantly more girls than boys reported with spontaneous intracranial hemorrhage. We investigated vascular development, homeostasis, and bleeding in Jag1Ndr/Ndr mice, using retina as a model. Jag1Ndr/Ndr mice displayed sporadic brain bleeds, a thin skull, tortuous blood vessels, sparse arterial smooth muscle cell coverage in multiple organs, which could be aggravated by hypertension, and sex-specific venous defects. Importantly, we demonstrated that retinographs from patients display similar characteristics with significantly increased vascular tortuosity. In conclusion, there are clinically important sex differences in vascular disease in ALGS, and retinography allows non-invasive vascular analysis in patients. Finally, Jag1Ndr/Ndr mice represent a new model for vascular compromise in ALGS.

Alagille Syndrome: Current Understanding of Pathogenesis, and Challenges in Diagnosis and Management

Alagille syndrome (ALGS) is a complex heterogenous disease with a wide array of clinical manifestations in association with cholestatic liver disease. Major clinical and genetic advancements have taken place since its first description in 1969. However, clinicians continue to face considerable challenges in the management of ALGS, particularly in the absence of targeted molecular therapies. In this article, we provide an overview of the broad ALGS phenotype, current approaches to diagnosis and with particular focus on key clinical challenges encountered in the management of these patients.

Re-evaluation of Laparoscopic Hepatic Subcapsular Spider-Like Telangiectasis Sign: A Highly Accurate Method to Diagnose Biliary Atresia in Infants

OBJECTIVE

Operative cholangiography, the gold standard for the diagnosis of biliary atresia (BA), is being challenged due to an increase in the studies of misdiagnosis. A previous study has shown that the laparoscopic hepatic subcapsular spider-like telangiectasis (HSST) sign was accurate for diagnosing BA. This study aims to compare the performance of the HSST sign with cholangiography in the identification of BA.

METHODS

We prospectively screened consecutive infants with cholestasis who underwent laparoscopic exploration in this multicenter study. Demographics, intraoperative findings (videos and images), and outcomes were retrospectively analyzed. The data of the HSST sign and cholangiography were compared according to the final diagnosis. Then, the diagnostic accuracy of the BA using the HSST sign and cholangiography was validated in other independent cohorts.

RESULTS

A total of 2,216 patients were enrolled in this study. The sensitivity and negative predictive values were both 100% for diagnosing BA based on the HSST sign and cholangiography. The specificity, negative predictive value, and accuracy of the HSST sign (97.2, 99.2, 99.3%) in discriminating BA were significantly higher than operative cholangiography (81.6, 94.9, 95.8; p < 0.001). Moreover, to realize the early diagnosis of BA, the accuracy of the HSST sign in identifying BA was better than cholangiography in the subgroup of neonates (98.7% vs. 95.0%; p = 0.032). Interestingly, 92 non-BA patients without the HSST sign had positive cholangiography. Among them, 28 infants had negative cholangiography when the common bile duct was compressed and 39 patients displayed visible bile ducts due to repeated postoperative biliary irrigation. The other 25 patients (18 with the Alagille syndrome, 5 with progressive familial intrahepatic cholestasis, and 2 with the neonatal hepatitis syndrome) had consistently positive cholangiography. In the independent validation cohort, the diagnostic accuracy of the HSST sign (99.2%) was higher than cholangiography (95.0%, p = 0.012).

CONCLUSION

The laparoscopic HSST sign is superior to cholangiography in the diagnosis of BA in the infants with cholestasis and has advantages in early diagnosis. This method is expected to become a novel shift for diagnosing BA during ongoing laparoscopy.

Alagille Syndrome: Diagnostic Challenges and Advances in Management

Alagille syndrome (ALGS) is a multisystem disease characterized by cholestasis and bile duct paucity on liver biopsy in addition to variable involvement of the heart, eyes, skeleton, face, kidneys, and vasculature. The identification of JAG1 and NOTCH2 as disease-causing genes has deepened our understanding of the molecular mechanisms underlying ALGS. However, the variable expressivity of the clinical phenotype and the lack of genotype-phenotype relationships creates significant diagnostic and therapeutic challenges. In this review, we provide a comprehensive overview of the clinical characteristics and management of ALGS, and the molecular basis of ALGS pathobiology. We further describe unique diagnostic considerations that pose challenges to clinicians and outline therapeutic concepts and treatment targets that may be available in the near future.

Genetic Basis of Human Congenital Heart Disease

Congenital heart disease (CHD) is the most common major congenital anomaly with an incidence of ∼1% of live births and is a significant cause of birth defect-related mortality. The genetic mechanisms underlying the development of CHD are complex and remain incompletely understood. Known genetic causes include all classes of genetic variation including chromosomal aneuploidies, copy number variants, and rare and common single-nucleotide variants, which can be either de novo or inherited. Among patients with CHD, ∼8%-12% have a chromosomal abnormality or aneuploidy, between 3% and 25% have a copy number variation, and 3%-5% have a single-gene defect in an established CHD gene with higher likelihood of identifying a genetic cause in patients with nonisolated CHD. These genetic variants disrupt or alter genes that play an important role in normal cardiac development and in some cases have pleiotropic effects on other organs. This work reviews some of the most common genetic causes of CHD as well as what is currently known about the underlying mechanisms.

Oral manifestations of Alagille syndrome

Alagille syndrome (AGS) is a multisystem disorder classically involving liver and heart failure, characteristic vertebral and facial features and ocular abnormalities. AGS is caused by heterozygous mutations in JAG1 or NOTCH2, with variable phenotype penetrance. We report two cases of AGS in children with tooth defects characterised by green discolouration and hypomineralisation. The role of hyperbilirubinaemia (HB) in this atypical colour, a classical feature of AGS, has been well described. However, it does not totally explain the dental phenotype. As JAG1 and NOTCH2 mutations can affect bone development and considering common physiological pathways between bone and tooth mineralisation, both mutations could participate in this unusual dental phenotype. The role of HB and genetics in the development of the dental phenotype of AGS is discussed in two prototypical cases. Future research should focus on the underlying genetic component of tooth abnormalities.

Outcomes of Childhood Cholestasis in Alagille Syndrome: Results of a Multicenter Observational Study

Alagille syndrome (ALGS) is an autosomal dominant multisystem disorder with cholestasis as a defining clinical feature. We sought to characterize hepatic outcomes in a molecularly defined cohort of children with ALGS-related cholestasis. Two hundred and ninety-three participants with ALGS with native liver were enrolled. Participants entered the study at different ages and data were collected retrospectively prior to enrollment, and prospectively during the study course. Genetic analysis in 206 revealed JAGGED1 mutations in 91% and NOTCH2 mutations in 4%. Growth was impaired with mean height and weight z-scores of <-1.0 at all ages. Regression analysis revealed that every 10 mg/dL increase in total bilirubin was associated with a decrease in height z-score by 0.10 (P = 0.03) and weight z-score by 0.15 (P = 0.007). Total bilirubin was higher for younger participants (P = 0.03) with a median of 6.9 mg/dL for those less than 1 year old compared with a median of 1.3 mg/dL for participants 13 years or older. The median gamma glutamyl transferase also dropped from 612 to 268 in the same age groups. After adjusting for age, there was substantial within-individual variation of alanine aminotransferase. By 20 years of age, 40% of participants had developed definite portal hypertension. Estimated liver transplant-free survival at the age of 18.5 years was 24%. Conclusions: This is the largest multicenter natural history study of cholestasis in ALGS, demonstrating a previously underappreciated burden of liver disease with early profound cholestasis, a second wave of portal hypertension later in childhood, and less than 25% of patients reaching young adulthood with their native liver. These findings will promote optimization of ALGS management and development of clinically relevant endpoints for future therapeutic trials.

Pulmonary hemorrhage in children with Alagille syndrome undergoing cardiac catheterization

OBJECTIVES

To evaluate the incidence, severity, and outcomes of pulmonary hemorrhage in children with Alagille syndrome (AGS) undergoing cardiac catheterization, and to find variables associated with hemorrhage in this population.

BACKGROUND

Children with AGS have a high incidence of bleeding complications during invasive procedures. It has been our impression that catheterization-associated pulmonary hemorrhage is more common in children with AGS, but there are no published data on this topic.

METHODS

This was a retrospective single institution study of children with AGS undergoing catheterization from 2010 to 2018. Pulmonary hemorrhage was defined as angiographic or fluoroscopic evidence of extravasated blood in the lung parenchyma, or blood suctioned from the endotracheal tube with documentation of pulmonary hemorrhage by the anesthesiologist or intensivist. Univariate comparisons were made between catheterizations that did and did not have pulmonary hemorrhage.

RESULTS

Thirty children with AGS underwent 87 catheterizations, 32 (37%) with interventions on the branch pulmonary arteries (PA). There were 26 (30%) procedures with hemorrhage, the majority (65%) of which were self-limited or required less than 24 hr of mechanical ventilation. Moderate and severe hemorrhage occurred only in children with tetralogy of Fallot (TOF; 5 of 14, 36%). A higher right ventricle to aorta systolic pressure ratio (1.0 [0.85-1.1] vs. 0.88 [0.59-1.0], p = .029) and interventions on the branch PAs (14 of 26, 54% vs. 18 of 61, 30%, p = .032) were associated with hemorrhage.

CONCLUSIONS

Pulmonary hemorrhage was common in children with AGS undergoing both intervention and diagnostic cardiac catheterization, and was associated with TOF, higher RV to aorta pressure ratio, and interventions on the branch PAs.

Visceral artery anomalies in patients with Alagille syndrome

BACKGROUND

Intracranial and pulmonary vascular anomalies are well-known complications and causes of mortality in AGS; however, visceral artery anomalies are less commonly recognized. Herein, we present a retrospective analysis of our experience with pediatric LDLT that focuses on the current problems with and treatments for visceral artery anomalies in AGS after LDLT.

METHODS

Between May 2001 and December 2017, 294 LDLTs were performed for 285 pediatric recipients. Of these, 13 LDLTs (4.4%) for 12 AGS patients were performed. We classified the visceral artery anomalies into aneurysms and stenosis.

RESULTS

The overall incidence of visceral aneurysm was 2 of 12 recipients (16.7%) and included a SMA aneurysm in one patient and an IPDA aneurysm with a subsequent SPA aneurysm in one patient; the ages of the diagnosis of visceral aneurysm were 16.3, 21.1, and 21.7 y, respectively. An endovascular treatment was performed for a progressive IPDA saccular aneurysm (12.0 × 14.5 × 15.0 mm). The overall incidence of visceral artery stenosis was 7 of 12 recipients (58.3%) and the median age at the diagnosis of visceral artery stenosis was 15.5 y (range 1.7-22.9 y). All 3 AGS patients with RA stenosis suffered from renal dysfunction (eGFR of 51, 78, and 51 mL/min/1.73m² ).

CONCLUSION

The morbidity of visceral artery anomalies is not negligible. The performance of periodic imaging examinations is necessary, even for infants, because it is difficult to detect visceral vascular anomalies in the infant stage.

Alagille Syndrome

Alagille syndrome is a complex multisystem autosomal dominant disorder with a wide variability in penetrance of clinical features. A majority of patients have pathogenic mutations in either the JAG1 gene, encoding a Notch pathway ligand, or the receptor NOTCH2. No genotype-phenotype correlations have been found in any organ system. Liver disease is a major cause of morbidity in this population, whereas cardiac and vascular involvement accounts for most of the mortality. Current therapies are supportive, but the future is promising for the development of targeted interventions to augment Notch pathway signaling in involved tissues.

Outcomes of Alagille syndrome following the Kasai operation: a systematic review and meta-analysis

PURPOSE

Infants with Alagille syndrome (AGS) frequently develop neonatal cholestasis, and some AGS infants who suspected of biliary atresia subsequently undergo the Kasai operation with the diagnosis of biliary atresia. The aim of this study was to investigate the effect of the Kasai operation on liver and patient outcomes among AGS patients, using a meta-analysis.

METHODS

A systematic review and meta-analysis of studies describing the outcomes of AGS patients with/without the Kasai operation were conducted. The analyzed outcomes were liver transplantation, not living with the native liver, and mortality for any reason.

RESULTS

We identified 6 studies (394 AGS patients). All studies were retrospective cohort or case-control studies. The incidences of liver transplantation, not living with the native liver, and mortality were significantly higher in AGS patients who underwent the Kasai operation than in those who did not undergo the Kasai operation (odds ratio: 6.46, 95% CI 3.23-12.89, p < 0.00001; odds ratio: 25.88, 95% CI 2.83-236.84, p < 0.004; odds ratio: 15.05, 95% CI 2.70-83.93, p = 0.002, respectively).

CONCLUSION

The Kasai operation was associated with poor outcomes in AGS patients. It remains unclear if the Kasai operation directly deteriorates liver and patient outcomes in AGS patients.

Systematic Review: The Epidemiology, Natural History, and Burden of Alagille Syndrome

BACKGROUND AND AIM

Alagille syndrome (ALGS) is an inherited multisystem disorder typically manifesting as cholestasis, and potentially leading to end-stage liver disease and death. The aim of the study was to perform the first systematic review of the epidemiology, natural history, and burden of ALGS with a focus on the liver component.

METHODS

Electronic databases and proceedings from key congresses were searched in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2009 guidelines. This analysis included publications reporting epidemiology, natural history, economic burden or health-related quality of life (HRQoL) outcomes in patients with ALGS.

RESULTS

Of 525 screened publications, 20 met the inclusion criteria. Liver-related features included cholestasis (87%-100% of patients), jaundice (66%-85%), and cirrhosis (44%-95%). Between 15% and 47% of patients underwent liver transplantation and 4% to 14% received partial biliary diversion. Pruritus affected the majority of patients (59%-88%, of whom up to 45% had severe pruritus) and manifested during the first 10 years of life. Children with ALGS had significantly impaired HRQoL compared with healthy controls and those with other diseases. Itching was the symptom that most affected children with ALGS. No study assessed the economic burden of ALGS.

CONCLUSIONS

Our findings consolidate information on the clinical course of ALGS, and highlight gaps in knowledge, most notably the absence of any research on the economic consequences of the disease. Further research is needed to establish the incidence of genetically confirmed ALGS. Disease-specific tools are also needed to improve the measurement of symptoms, such as itching, and better understand the impact of ALGS on HRQoL.

Wilms Tumor After Orthotopic Liver Transplant in a Patient With Alagille Syndrome

We present a case of Wilms Tumor in a patient with Alagille syndrome 10 months after liver transplant. We explore a suggested genetic connection between these 2 diseases. In children with Wilms Tumor, we propose a pathoembryologic explanation for not just the tumor, but also for the cause of associated benign ureteral and renal parenchymal aberrancies that are commonly seen in the Alagille population. We also discuss the diagnostic and therapeutic challenges that can arise in a liver transplant patient with Alagille syndrome who subsequently develops a renal mass.

Clinical Features and Genetic Analysis of Pediatric Patients with Alagille Syndrome Presenting Initially with Liver Function Abnormalities

Alagille syndrome (AGS) is a multisystem disorder and caused by mutations in JAG1 or NOTCH2 gene. The diagnosis of AGS is hampered by its highly variable clinical manifestations. We performed a retrospective analysis on 16 children diagnosed as having AGS in recent five years in our hospital. Cholestasis was seen in 15 patients (93.8%), heart disease in 12 (75%), characteristic facies in 7 (43.8%), and butterfly vertebrae in 7 (43.8%). Ophthalmology examination was not performed on all the patients. Further, serum biochemical parameters were compared between AGS and 16 biliary atresia (BA) patients who were confirmed by surgery. Elevated liver enzymes were seen in all the patients. Serum total cholesterol (TC) (P=0.0007), alanine aminotransferase (ALT) (P=0.0056), aspartate aminotransferase (AST) (P=0.0114), gamma-glutamyl transferase (GGT) (P=0.035) and total bile acid (TBA) levels (P=0.042) were significantly elevated in AGS patients compared to those in BA cases. However, there were no significant differences in serum total bilirubin (TB), conjugated bilirubin (CB) and albumin (ALB) between the two groups. We identified 14 different JAG1 gene variations and 1 NOTCH2 gene mutation in 16 Chinese AGS patients. Our study suggested clinical features of AGS are highly variable and not all patients meet the classical diagnostic criteria. It was suggested that hypercholesterolaemia and significantly elevated GGT, TBA and ALT may be helpful to diagnose AGS. Genetic testing is integral in the diagnosis of AGS.

The "ins and outs" of complement-driven immune responses

The complement system represents an evolutionary old and critical component of innate immunity where it forms the first line of defense against invading pathogens. Originally described as a heat-labile fraction of the serum responsible for the opsonization and subsequent lytic killing of bacteria, work over the last century firmly established complement as a key mediator of the general inflammatory response but also as an acknowledged vital bridge between innate and adaptive immunity. However, recent studies particularly spanning the last decade have provided new insights into the novel modes and locations of complement activation and highlighted unexpected additional biological functions for this ancient system, for example, in regulating basic processes of the cell. In this review, we will cover the current knowledge about complement's established and novel roles in innate and adaptive immunity with a focus on the functional differences between serum circulating and intracellularly active complement and will describe and discuss the newly discovered cross-talks of complement with other cell effector systems particularly during T-cell induction and contraction.

A case of Alagille syndrome presenting with chronic cholestasis in an adult

Alagille syndrome (AGS) is a complex multisystem disorder that involves mainly the liver, heart, eyes, face, and skeleton. The main associated clinical features are chronic cholestasis due to a paucity of intrahepatic bile ducts, congenital heart disease primarily affecting pulmonary arteries, vertebral abnormalities, ocular embryotoxon, and peculiar facies. The manifestations generally become evident at a pediatric age. AGS is caused by defects in the Notch signaling pathway due to mutations in JAG1 or NOTCH2. It is inherited in an autosomal dominant pattern with a high degree of penetrance, but variable expressivity results in a wide range of clinical features. Here we report on a 31-year-old male patient who presented with elevated serum alkaline phosphatase and gamma-glutamyl transpeptidase, and was diagnosed with AGS associated with the JAG1 mutation after a comprehensive workup.

Exocrine pancreatic function in children with Alagille syndrome

Alagille syndrome (AGS) is often associated with symptoms of maldigestion, such as steatorrhea, hypotrophy and growth retardation. Exocrine pancreatic insufficiency was proposed as the underlying cause. We aimed to assess the exocrine pancreatic function with the use of different methods in AGS patients. Concentrations of fecal elastase-1 (FE1) and fecal lipase (FL) activities were measured in 33 children with AGS. The C-mixed triglyceride breath test (MTBT) in a subgroup comprising 15 patients. In all patients studied, FE1 concentrations and FL activities were normal. Abnormal MTBT results were documented in 4 (26.7%) patients. The FE1 and FL levels in MTBT-positive and MTBT-negative children did not differ. The results of this research do not confirm the presence of exocrine pancreatic dysfunction in AGS patients. Routine screening for exocrine pancreatic insufficiency of this group of patients is not necessary.

THBS2 Is a Candidate Modifier of Liver Disease Severity in Alagille Syndrome

BACKGROUND & AIMS

Alagille syndrome is an autosomal-dominant, multisystem disorder caused primarily by mutations in JAG1, resulting in bile duct paucity, cholestasis, cardiac disease, and other features. Liver disease severity in Alagille syndrome is highly variable, however, factors influencing the hepatic phenotype are unknown. We hypothesized that genetic modifiers may contribute to the variable expressivity of this disorder.

METHODS

We performed a genome-wide association study in a cohort of Caucasian subjects with known pathogenic JAG1 mutations, comparing patients with mild vs severe liver disease, followed by functional characterization of a candidate locus.

RESULTS

We identified a locus that reached suggestive genome-level significance upstream of the thrombospondin 2 (THBS2) gene. THBS2 codes for a secreted matricellular protein that regulates cell proliferation, apoptosis, and angiogenesis, and has been shown to affect Notch signaling. By using a reporter mouse line, we detected thrombospondin 2 expression in bile ducts and periportal regions of the mouse liver. Examination of Thbs2-null mouse livers showed increased microvessels in the portal regions of adult mice. We also showed that thrombospondin 2 interacts with NOTCH1 and NOTCH2 and can inhibit JAG1-NOTCH2 interactions.

CONCLUSIONS

Based on the genome-wide association study results, thrombospondin 2 localization within bile ducts, and demonstration of interactions of thrombospondin 2 with JAG1 and NOTCH2, we propose that changes in thrombospondin 2 expression may further perturb JAG1-NOTCH2 signaling in patients harboring a JAG1 mutation and lead to a more severe liver phenotype. These results implicate THBS2 as a plausible candidate genetic modifier of liver disease severity in Alagille syndrome.

Immune dysregulation in Alagille syndrome: A new feature of the evolving phenotype

Alagille syndrome (ALGS) is a rare autosomal dominant, multi-system disease caused by mutations in one of two NOTCH signaling pathway genes. Mutations in JAG1 are found in more than 94% of patients, with associated Jagged1 defects. We previously showed that CD46, which is a complement and immune regulator, regulates NOTCH expression during T cell activation after binding to C3b/C4b. We have identified 25% of our ALGS cohort with frequent infections and studied a subgroup of 4 in detail who were not showing current features of infections in order to show if Jagged1 abnormalities could affect immune function. We used cytometric bead arrays and FACS to measure cytokines and cell membrane expression. Resting and activated T cells were studied in both low and high IL-2 concentration to assess the TH1 ability to shift from INFγ to IL-10 production. In vitro initial PBMC cell population and subpopulation assessment were normal but further assessment of the lymphocytes revealed that while NOTCH1 expression and regulation was normal on resting TH1, Jagged1 expression was exaggerated. Resting TH1 cells from some patients exhibited high CD132 levels. Upon activating T cells, TH1 cells managed to produce TNF but failed to produce sufficient IFNγ levels (in two patients TH1 produced no IFNγ). TH2 exhibited exaggerated response with high IL-4 and IL-5 levels. TH1 were unable to down-regulate CD127, resulting in prolonged immune activation, and failed to shift from IFNγ to IL-10 production maintaining high IL-2 levels suggesting an impaired T cell response. Disturbed CD46-Jagged1 interaction may explain recurrent infections among ALGS patients, and could predispose to Th2-driven conditions such as asthma, eczema, food allergies and airway atopy and otitis media. The ALGS description could now be extended to include immune dysregulation.

Outcome of Alagille Syndrome Patients Who Had Previously Received Kasai Operation during Infancy: A Single Center Study

PURPOSE

Infants with Alagille syndrome (AGS) are occasionally misdiagnosed as biliary atresia and subsequently undergo Kasai operation. The purpose of this study was to investigate the outcome of patients with AGS who had previously received Kasai operation during infancy.

METHODS

This retrospective study was conducted at the Department of Pediatrics, Samsung Medical Center. We compared the prognosis and mortality between those who had undergone Kasai operation during infancy (Kasai group) and those who had not (non-Kasai group).

RESULTS

Among the 15 children with AGS, five had received Kasai operation, while 10 had not. All subjects in the Kasai group revealed neonatal cholestasis, while 70% of the non-Kasai group showed neonatal cholestasis. Liver transplantation was performed in 100% (5/5) among the Kasai group, and 20.0% (2/10) among the non-Kasai group (p=0.007). Mortality was observed in 60.0% (3/5) among the Kasai group, and 10.0% (1/10) among the non-Kasai group (p=0.077).

CONCLUSION

Although overall mortality rate did not significantly differ between the two groups, the proportion of patients receiving liver transplantation was significantly higher in the non-Kasai group. The relatively worse outcome in AGS patients who had received Kasai operation may be due to the unfavorable influences of Kasai operation on the clinical course of AGS, or maybe due to neonatal cholestasis, irrespective of the Kasai operation.

Clinical features, outcomes, and genetic analysis in Korean children with Alagille syndrome

BACKGROUND

Alagille syndrome (AGS) is a multisystem autosomal dominant disorder that affects the liver, heart, eyes, face, bone, and other organs. AGS is caused by mutations in one of two genes, JAG1 or NOTCH2. We evaluated clinical features, outcomes, and the presence of JAG1 and NOTCH2 mutations in Korean children with AGS.

METHODS

Between January 1997 and December 2013, 19 children were diagnosed with AGS at Asan Medical Center, Seoul, Korea. Their clinical features, outcomes, and JAG1 and NOTCH2 mutation status were retrospectively analyzed.

RESULTS

The prevalence of clinical features in the 19 patients was as follows: dysmorphic facial features, 100% (n = 19); liver symptoms, 89% (n = 17); cardiac symptoms, 95% (n = 18); ophthalmologic symptoms, 67% (n = 10); skeletal deformities, 47% (n = 9); and renal symptoms, 21% (n = 4). JAG1 mutations were identified in 14 patients. The 13 different JAG1 mutations, seven of which were novel, included four deletions, three insertions, two missense mutations, three nonsense mutations, and one indel mutation. No NOTCH2 mutations were found. Two patients who received liver transplantation due to liver failure were still alive. Two patients died of comorbidities related to AGS: one of cardiac failure and one of hepatic failure.

CONCLUSION

This study describes the clinical characteristics of 19 Korean AGS patients with seven novel JAG1 mutations. Neonatal cholestatic jaundice was the most common initial presenting symptom; thus the presence of neonatal cholestasis warrants screening for syndromic features of AGS. Complex heart anomalies and progressive liver dysfunction resulted in significant morbidity and mortality in AGS.

Subarachnoid hemorrhage due to aneurysm rupture in a young woman with Alagille syndrome - A rare cause of sudden death

The Alagille syndrome (AGS) or arteriohepatic dysplasia is a rare, autosomal dominant inherited disease with a prevalence of approximately 1:100,000. AGS was first described in 1969 and affects liver, heart, arterial blood vessels, skeleton and the eyes. The expression of AGS is variable. In severe cases a liver transplantation is required. Presented is the case of a 25-year-old woman with AGS. At the age of 7 and 8years she had liver transplantations. Other typical findings associated with Alagille syndrome (e.g. pulmonary or renal anomalies) were also present. The young woman apparently died suddenly and unexpectedly in a good health condition despite regular medical treatment. Cause of death was a subarachnoid hemorrhage with invasion of the hemorrhage into the ventricle system caused by a rupture of previously unknown large aneurysm in the terminal basilary artery. Intracranial vascular malformations are a common finding in patients with AGS and cause death in up to 16% of them. Life expectancy in AGS patients depends on the severity of changes of the affected liver. But AGS is also responsible for various vascular abnormalities in several other organs which can cause lethal complications. Due to the high rate of vascular complications and intracranial hemorrhage with the leading cause of mortality in patients with AGS, vascular screening by the use of noninvasive imaging techniques (CT or MR angiography) is required to avoid unexpected sudden death.

CHARGE syndrome: a review of the immunological aspects

CHARGE syndrome is caused by a dominant variant in the CHD7 gene. Multiple organ systems can be affected because of haploinsufficiency of CHD7 during embryonic development. CHARGE syndrome shares many clinical features with the 22q11.2 deletion syndrome. Immunological abnormalities have been described, but are generally given little attention in studies on CHARGE syndrome. However, structured information on immunological abnormalities in CHARGE patients is necessary to develop optimal guidelines for diagnosis, treatment and follow-up in these patients. Here, we provide an overview of the current literature on immunological abnormalities in CHARGE syndrome. We also explore immunological abnormalities in comparable multiple congenital anomaly syndromes to identify common immunological phenotypes and genetic pathways that might regulate the immune system. Finally, we aim to identify gaps in our knowledge on the immunological aspects in CHARGE syndrome that need further study.

Medical and dental management of Alagille syndrome: a review

Alagille syndrome is a rare, autosomal, complex, dominant disorder associated with dysfunction of the liver, heart, skeleton, and eyes, as well as characteristic facial appearance. It is associated with the defect in component of the Notch signalling pathway. Here, we review the main features of Alagille syndrome with special focus on oro-facial manifestations like prominent forehead, moderate hypertelorism with deep-set eyes, a saddle or straight nose with a flattened, bulbous tip, and large ears. The article is based on the most recent and significant literature available from the Medline database.

Contrary to healthy children, patients with Alagille syndrome have many problems, depending on several factors like the severity of cholestasis and scarring in the liver, heart or lung problems, presence of infections, or other problems related to poor nutrition that can manifest in their oral cavity in the dental and periodontal tissues, as well as oral mucosa. From the dentist’s view, the most important elements are careful observation, accurate diagnosis, and planned management of such patients, especially during the patient’s formative years, to prevent complications. Aggressive preventive oral care and consultations with medical specialists before any invasive procedure are obligatory. All this can improve quality of life in patients with Alagille syndrome.

Renal involvement and the role of Notch signalling in Alagille syndrome

Alagille syndrome is an autosomal dominant disorder with variable multisystem organ involvement that is caused by mutations in one of two genes in the Notch signalling pathway, JAG1 or NOTCH2. Alagille syndrome is characterized by bile duct paucity, along with at least three of the following features: cholestasis, cardiac defects, skeletal abnormalities, ocular abnormalities and characteristic facies. However, the clinical features of Alagille syndrome are highly variable, and children or adults may also present with predominantly renal findings and little or no hepatic involvement. Renal involvement occurs in 40% of JAG1-mutation-positive individuals. Renal insufficiency is common and has been specifically reported in children with Alagille syndrome who have end-stage liver disease. The role of NOTCH2 and JAG1 in formation of proximal nephron structures and podocytes might explain the observed phenotypes of renal dysplasia and proteinuria in patients with Alagille syndrome, and renal tubular acidosis may be the result of JAG1 expression in the collecting ducts. Renal vascular hypertension in patients with Alagille syndrome is explained by the widespread vasculopathy and the role of Notch signalling in vascular development. Increased awareness of Alagille syndrome amongst nephrologists may lead to more diagnoses of Alagille syndrome in patients with apparently isolated renal disease.

The CD46-Jagged1 interaction is critical for human TH1 immunity

CD46 is a complement regulator with important roles related to the immune response. CD46 functions as a pathogen receptor and is a potent costimulator for the induction of interferon-γ (IFN-γ)-secreting effector T helper type 1 (T(H)1) cells and their subsequent switch into interleukin 10 (IL-10)-producing regulatory T cells. Here we identified the Notch family member Jagged1 as a physiological ligand for CD46. Furthermore, we found that CD46 regulated the expression of Notch receptors and ligands during T cell activation and that disturbance of the CD46-Notch crosstalk impeded induction of IFN-γ and switching to IL-10. Notably, CD4(+) T cells from CD46-deficient patients and patients with hypomorphic mutations in the gene encoding Jagged1 (Alagille syndrome) failed to mount appropriate T(H)1 responses in vitro and in vivo, which suggested that CD46-Jagged1 crosstalk is responsible for the recurrent infections in subpopulations of these patients.

Outcomes of liver transplantation for patients with Alagille syndrome: the studies of pediatric liver transplantation experience

Alagille syndrome (ALGS) is a multisystem disorder that manifests as childhood cholestasis. Reports of liver transplantation (LT) for patients with ALGS have come largely from single centers, which have reported survival rates of 57% to 79%. The aim of this study was to determine LT outcomes for patients with ALGS. We performed a retrospective analysis of the Studies of Pediatric Liver Transplantation database, which contains information about 3153 pediatric LT recipients. Data were available for 91 patients with ALGS and for 236 age-matched patients with biliary atresia (BA). The frequency of complex cardiac anomalies was lower in the LT group with ALGS versus published ALGS series (5% versus 13%). The pretransplant glomerular filtration rate (GFR) was <90 mL/minute/1.73 m(2) in 18% of the LT patients with ALGS and in 5% of the LT patients with BA (P < 0.001). The height deficit at listing was worse for the ALGS patients (66%) versus the BA patients (22%). The 1-year patient survival rates were 87% for the ALGS patients and 96% for the BA patients (P = 0.002). The deaths in the ALGS group mostly occurred within the first 30 days. No pretransplant factors associated with death were identified in the ALGS group. A survival analysis revealed that biliary (P = 0.02), vascular (P < 0.001), central nervous system (CNS; P < 0.001), and renal complications (P < 0.001) after LT were associated with death in the ALGS group. Renal insufficiency in the ALGS patients worsened after LT, and at 1 year, GFR was <90 mL/minute/1.73 m(2) in 22% of the LT patients with ALGS but in only 8% of the patients with BA (P = 0.0014). More LT pediatric patients with ALGS either were currently receiving special education (50% versus 30% for BA patients, P = 0.02) or had received special education in the past (60% versus 36%, P = 0.01). Vascular, CNS, and renal complications were increased in the ALGS patients after LT, and this reflected multisystem involvement. Although the 1-year survival rate was modestly lower for the ALGS patients versus the BA patients, the clustering of deaths within the first 30 days is notable and warrants increased vigilance and further investigation.

Alagille syndrome in a Vietnamese cohort: mutation analysis and assessment of facial features

Alagille syndrome (ALGS, OMIM #118450) is an autosomal dominant disorder that affects multiple organ systems including the liver, heart, eyes, vertebrae, and face. ALGS is caused by mutations in one of two genes in the Notch Signaling Pathway, Jagged1 (JAG1) or NOTCH2. In this study, analysis of 21 Vietnamese ALGS individuals led to the identification of 19 different mutations (18 JAG1 and 1 NOTCH2), 17 of which are novel, including the third reported NOTCH2 mutation in Alagille Syndrome. The spectrum of JAG1 mutations in the Vietnamese patients is similar to that previously reported, including nine frameshift, three missense, two splice site, one nonsense, two whole gene, and one partial gene deletion. The missense mutations are all likely to be disease causing, as two are loss of cysteines (C22R and C78G) and the third creates a cryptic splice site in exon 9 (G386R). No correlation between genotype and phenotype was observed. Assessment of clinical phenotype revealed that skeletal manifestations occur with a higher frequency than in previously reported Alagille cohorts. Facial features were difficult to assess and a Vietnamese pediatric gastroenterologist was only able to identify the facial phenotype in 61% of the cohort. To assess the agreement among North American dysmorphologists at detecting the presence of ALGS facial features in the Vietnamese patients, 37 clinical dysmorphologists evaluated a photographic panel of 20 Vietnamese children with and without ALGS. The dysmorphologists were unable to identify the individuals with ALGS in the majority of cases, suggesting that evaluation of facial features should not be used in the diagnosis of ALGS in this population. This is the first report of mutations and phenotypic spectrum of ALGS in a Vietnamese population.

NOTCH2 mutations in Alagille syndrome

BACKGROUND

Alagille syndrome (ALGS) is a dominant, multisystem disorder caused by mutations in the Jagged1 (JAG1) ligand in 94% of patients, and in the NOTCH2 receptor in <1%. There are only two NOTCH2 families reported to date. This study hypothesised that additional NOTCH2 mutations would be present in patients with clinical features of ALGS without a JAG1 mutation.

METHODS

The study screened a cohort of JAG1-negative individuals with clinical features suggestive or diagnostic of ALGS for NOTCH2 mutations.

RESULTS

Eight individuals with novel NOTCH2 mutations (six missense, one splicing, and one non-sense mutation) were identified. Three of these patients met classic criteria for ALGS and five patients only had a subset of features. The mutations were distributed across the extracellular (N=5) and intracellular domains (N=3) of the protein. Functional analysis of four missense, one nonsense, and one splicing mutation demonstrated decreased Notch signalling of these proteins. Subjects with NOTCH2 mutations demonstrated highly variable expressivity of the affected systems, as with JAG1 individuals. Liver involvement was universal in NOTCH2 probands and they had a similar prevalence of ophthalmologic and renal anomalies to JAG1 patients. There was a trend towards less cardiac involvement in the NOTCH2 group (60% vs 100% in JAG1). NOTCH2 (+) probands exhibited a significantly decreased penetrance of vertebral abnormalities (10%) and facial features (20%) when compared to the JAG1 (+) cohort.

CONCLUSIONS

This work confirms the importance of NOTCH2 as a second disease gene in ALGS and expands the repertoire of the NOTCH2 related disease phenotype.

Renal anomalies in Alagille syndrome: a disease-defining feature

Alagille syndrome (ALGS) is an autosomal dominant condition, primarily caused by mutations in JAGGED1. ALGS is defined by cholestatic liver disease, cardiac disease and involvement of the face, skeleton, and eyes with variable expression of these features. Renal involvement has been reported though not formally described. The objective of this study was to systematically characterize the renal involvement in ALGS. We performed a retrospective review of 466 JAGGED1 mutation-positive ALGS patients. Charts were reviewed for serum biochemistries, renal ultrasounds or other imaging, urinalysis, and clinical reports from pediatric nephrologists. The clinical data were reviewed by two pediatric hepatologists and a pediatric nephrologist. Of 466 charts reviewed we found 187 yielded evaluable renal information. Of these, 73/187 were shown to have renal involvement, representing 39% of the study cohort. Renal dysplasia was the most common anomaly seen. Genotype analysis of the JAGGED1 mutations in the patients with and without renal involvement did not reveal an association with mutation type. From the study we concluded that renal involvement has a prevalence of 39% in ALGS in our evaluable patients. Renal dysplasia is the most common renal anomaly. This finding correlates with the known role of the Notch pathway in glomerular development. Since renal disease of the type seen in ALGS can impair growth and impact liver transplantation, there is a clear need for a prospective study of renal involvement in ALGS and the development of guidelines for evaluation and management. These data also suggest that renal involvement be considered the sixth defining criterion for ALGS.

Perthes-like disease in Alagille syndrome

We describe a unique case of a bilateral osteochondrosis of the femoral heads, similar to Perthes disease, in a boy affected by Alagille syndrome. This is a rare genetic syndrome, caused by vascular anomalies, and characterized by five main features: hepatic, cardiovascular, ophthalmological, skeletal malformations, and characteristic facial appearance. The most frequent skeletal finding is the 'butterfly vertebra'. We have followed the patient from the age of 5 years to the age of 20 years. We performed two bilateral valgus osteotomies when he was 10 years old to limit the progression of the deformity. We believe that the association of a bilateral osteochondrosis of the femoral heads with Alagille syndrome, a disease characterized by a vascular etiology, supports the hypothesis of angiogenic pathogenesis of Perthes disease.

Diagnosis of Alagille syndrome-25 years of experience at King's College Hospital

OBJECTIVE

The aim of the study was to study the clinical and histological features of Alagille syndrome (AGS) at presentation comparing the value of the various modalities before the implementation of genetic diagnosis.

PATIENTS AND METHODS

We performed a retrospective analysis of the records of 117 children diagnosed as having AGS after referral to King's College Hospital between 1980 and 2005.

RESULTS

Cholestasis was seen in 104 of 117 (89%), characteristic facies in 91 of 117 (77%), posterior embryotoxon in 72 of 117 (61%), butterfly vertebrae in 44 of 117 (39%), heart disease (most often peripheral pulmonary stenosis) in 107 of 117 (91%), and renal disease in 27 of 117 (23%). Serum cholesterol levels of >5 mmol/L were seen in 52 of 86 (60.4%). Liver biopsy showed characteristic features of paucity of interlobular bile ducts in 59 of 77 (76.6%) children younger than 16 weeks of age, in 10 of 14 (71.4%) between 16 weeks and 1 year of age, and in 8 of 12 (66.66%) older than 1 year of age. Other biopsy findings were those of nonspecific hepatitis and biliary features. Iminodiacetic acid scans showed no excretion of isotope into the bowel after 24 hours in 21 of 35 (60%), and small/no gallbladder on ultrasound was seen in 29 of 104 (27.8%). Eleven of 117 (9.4%) had a diagnostic laparotomy and operative cholangiography, 2 proceeding to Kasai portoenterostomy before referral to our unit.

CONCLUSIONS

Clinical features of AGS are not as consistently informative as suggested in the literature. Hypercholesterolaemia is nonspecific but may be a helpful pointer. Histology is not characteristic in 25%; hepatobiliary iminodiacetic acid scan and ultrasound may suggest a false diagnosis of biliary atresia in 60% and 28%, respectively, supporting the concept that infants with liver disease warrant early referral to a specialist centre. The advent of genetic diagnosis will redefine the syndrome with likely effects on the prognosis of the defined group.

Health status of patients with Alagille syndrome

OBJECTIVES

The aim of the study was to assess health-related quality of life (HRQOL) in children with Alagille syndrome (AGS) in comparison with a normative population and other chronic diseases, and also to examine the effect of AGS-specific morbidities on HRQOL.

PATIENTS AND METHODS

A cross-sectional study was performed using the Child Health Questionnaire Parent Form 50 (CHQ-PF50) to measure HRQOL in patients with AGS. AGS HRQOL was compared with that of a normative population and those previously studied by the CHQ, including juvenile rheumatoid arthritis, attention-deficit/hyperactivity disorder, and liver transplantation. AGS-specific questions were used in multiple regression analysis to determine correlation of features and symptoms of AGS with HRQOL.

RESULTS

Seventy-one patients with AGS, ages 5 to 18 years, were studied. Those families completing surveys demonstrated that children with AGS had significantly lower HRQOL (P < 0.05) compared with the normative sample. In comparison with children with juvenile rheumatoid arthritis, children with AGS had lower psychosocial function scores (P < 0.0005). In comparison with children with attention-deficit/hyperactivity disorder, children with AGS had lower physical function scores (P < 0.0005) but higher psychosocial function scores (P < 0.0005). Children with AGS had lower physical function scores than a liver transplant population (P < 0.05). Regression analysis indicated that cardiac catheterization or surgery, mental health diagnoses, and poor sleep were associated with lower CHQ scores in children with AGS.

CONCLUSIONS

In the first descriptive report of HRQOL in a large cohort of patients with AGS, HRQOL was impaired, indicating a significant burden of chronic disease in both physical and psychosocial health. Additional prospective evaluation is needed in multicenter collaboration.