Diagnostic algorithm for neonatal intrahepatic cholestasis integrating single-gene testing and next-generation sequencing in East Asia

BACKGROUND AND AIM

Advances in molecular genetics have uncovered causative genes responsible for neonatal cholestasis. Panel-based next-generation sequencing has been used clinically in infants with neonatal cholestasis. We aimed to evaluate the clinical application of single-gene testing and next-generation sequencing and to develop a diagnostic algorithm for neonatal intrahepatic cholestasis.

METHODS

From January 2010 to July 2021, patients suspected of having neonatal intrahepatic cholestasis were tested at the Seoul National University Hospital. If there was a clinically suspected disease, single-gene testing was performed. Alternatively, if it was clinically difficult to differentiate, a neonatal cholestasis gene panel test containing 34 genes was performed.

RESULTS

Of the total 148 patients examined, 49 (33.1%) were received a confirmed genetic diagnosis, including 14 with Alagille syndrome, 14 with neonatal intrahepatic cholestasis caused by citrin deficiency, 7 with Dubin-Johnson syndrome, 5 with arthrogryposis-renal dysfunction-cholestasis syndrome, 5 with progressive familial intrahepatic cholestasis type II, 1 with Rotor syndrome, 1 with Niemann-Pick disease type C, 1 with Kabuki syndrome, and 1 with Phenylalanyl-tRNA synthetase subunit alpha mutation. Sixteen novel pathogenic or likely pathogenic variants of neonatal cholestasis were observed in this study. Based on the clinical characteristics and laboratory findings, we developed a diagnostic algorithm for neonatal intrahepatic cholestasis by integrating single-gene testing and next-generation sequencing.

CONCLUSIONS

Alagille syndrome and neonatal intrahepatic cholestasis caused by citrin deficiency were the most common diseases associated with genetic neonatal cholestasis. Single-gene testing and next-generation sequencing are important and complementary tools for the diagnosis of genetic neonatal cholestasis.

THREE-YEAR FOLLOW-UP OF PROGRESSIVE CHORIORETINAL ATROPHY IN ATYPICAL ALAGILLE SYNDROME: A CASE REPORT

PURPOSE

To report a case of atypical Alagille syndrome with progressive chorioretinal atrophy.

METHODS

Case Report.

RESULTS

A 42-year-old Japanese man presented with atypical Alagille syndrome. At the first visit, funduscopy revealed anterior circumferential chorioretinal atrophy in the peripheral retina and peripapillary region with posterior pole sparing in both eyes. Fundus autofluorescence showed hypoautofluorescence in the peripheral and peripapillary regions, but normal findings in the macular region. After follow-up for 3 years, hypopigmented area with well visualized large choroidal vessels extended to mid-peripheral region. On Fundus autofluorescence images, hypoautofluorescence newly appeared in macular region in both eyes. Perivascular hypoautofluorescence and granular hyperautofluorescence scattering within the posterior pole were also observed. BCVA deteriorated and concentric visual field contraction worsened progressively.

CONCLUSION

Alagille syndrome is known to have many ophthalmic manifestations, most of which are stable with minimal threat to vision. In the present case, chorioretinal atrophy progressed during 3-year follow-up, suggesting that progression of chorioretinal atrophy with vision loss may occur over time in Alagille syndrome.

Hepatoblastoma in a cirrhotic child with Alagille syndrome

Alagille syndrome (AGS) is a genetic disorder due to mutations in the JAGGED 1 or NOTCH 2 genes leading to multisystemic manifestations. Though these patients are at risk of developing various liver tumours, no cases of hepatoblastoma among young children with cirrhosis in AGS have been reported. We report a male toddler, with cirrhosis due to AGS who developed a hepatoblastoma. He underwent a liver transplant for decompensated chronic liver disease with marked pruritus, very high alpha-fetoprotein levels and malignant liver lesions on positron emission tomography CT. His explant histology revealed a paucity of bile ducts and liver lesions turned out to be hepatoblastoma for which he received postoperative chemotherapy. The genetic testing sent before transplantation confirmed the clinical diagnosis of AGS. Hepatoblastoma should be suspected in any child with AGS presenting with a right upper quadrant mass even in the setting of chronic liver disease.

Jagged-mediated development and disease: Mechanistic insights and therapeutic implications for Alagille syndrome

Notch signaling controls multiple aspects of embryonic development and adult homeostasis. Alagille syndrome is usually caused by a single mutation in the jagged canonical Notch ligand 1 (JAG1), and manifests with liver disease and cardiovascular symptoms that are a direct consequence of JAG1 haploinsufficiency. Recent insights into Jag1/Notch-controlled developmental and homeostatic processes explain how pathology develops in the hepatic and cardiovascular systems and, together with recent elucidation of mechanisms modulating liver regeneration, provide a basis for therapeutic efforts. Importantly, disease presentation can be regulated by genetic modifiers, that may also be therapeutically leverageable. Here, we summarize recent insights into how Jag1 controls processes of relevance to Alagille syndrome, focused on Jag1/Notch functions in hepatic and cardiovascular development and homeostasis.

Successful Anesthesia Management of Pediatric Living Donor Liver Transplant With Mild Bilateral Pulmonary Artery Stenosis Due to Alagille Syndrome: A Case Report

Alagille syndrome is an autosomal-dominantinherited disease characterized by intrahepatic bile duct involvement, congenital heart disease, eye anomalies, skeletal and central nervous system involvement, kidney anomalies, and facial appearance. Liver transplant is the only treatment option for patients with end-stage liver disease and Alagille syndrome. Bilateral peripheral pulmonary artery stenosis is a contraindication for liver transplant due to high mortality, and the decision for liver transplant in patients with bilateral peripheral pulmonary artery stenosis is extremely challenging for anesthesiologists andtransplant surgeons.Wepresent a 2-year-oldfemale patient with successful anesthetic management of a pediatric living donor liver transplant with mild bilateral pulmonary artery stenosis, mild aortic stenosis, and mitral regurgitation due to Alagille syndrome. Anesthesiologists should know the underlying pathophysiological condition and perform a comprehensive preoperative evaluation to determine the correct anesthesia plan in patients with Alagille syndrome who will undergo liver transplants to treat multiple system disorders. Successful perioperative management of Alagille syndrome requires effective communication and collaboration between specialists through a multidisciplinary team approach.

Novel JAG1 variants leading to Alagille syndrome in two Chinese cases

Alagille Syndrome (ALGS) is a complex genetic disorder characterized by cholestasis, congenital cardiac anomalies, and butterfly vertebrae. The variable phenotypic expression of ALGS can lead to challenges in accurately diagnosing affected infants, potentially resulting in misdiagnoses or underdiagnoses. This study highlights novel JAG1 gene mutations in two cases of ALGS. The first case with a novel p.Pro325Leufs*87 variant was diagnosed at 2 months of age and exhibited a favorable prognosis and an unexpected manifestation of congenital hypothyroidism. Before the age of 2, the second patient was incorrectly diagnosed with liver structural abnormalities, necessitating extensive treatment. In addition, he exhibited delays in language acquisition that may have been a result of SNAP25 haploinsufficiency. The identification of ALGS remains challenging, highlighting the importance of early detection and genetic testing for effective patient management. The variant p.Pro325Leufs*87 is distinct from reported variants linked to congenital hypothyroidism in ALGS patients, thereby further confirming the clinical and genetic complexity of ALGS. This emphasizes the critical need for individualized and innovative approaches to diagnosis and medical interventions, uniquely intended to address the complexity of this syndrome.

Cardiac complications caused by biliary diseases: A review of clinical manifestations, pathogenesis and treatment strategies of cholecardia syndrome

Gallbladder and biliary diseases (GBDs) are one of the most common digestive diseases. The connections between GBDs and several organs other than the liver have gradually surfaced accompanied by the changes in people's diet structure and the continuous improvement of medical diagnosis technology. Among them, cholecardia syndrome that takes the heart as the important target of GBDs complications has been paid close attention. However, there are still no systematic report about its corresponding clinical manifestations and pathogenesis. This review summarized recent reported types of cholecardia syndrome and found that arrhythmia, myocardial injury, acute coronary syndrome and heart failure are common in the general population. Besides, the clinical diagnosis rate of intrahepatic cholestasis of pregnancy (ICP) and Alagille syndrome associated with gene mutation is also increasing. Accordingly, the underlying pathogenesis including abnormal secretion of bile acid, gene mutation, translocation and deletion (JAG1, NOTCH2, ABCG5/8 and CYP7A1), nerve reflex and autonomic neuropathy were further revealed. Finally, the potential treatment measures and clinical medication represented by ursodeoxycholic acid were summarized to provide assistance for clinical diagnosis and treatment.

Protein biomarkers GDF15 and FGF21 to differentiate mitochondrial hepatopathies from other pediatric liver diseases

BACKGROUND

Mitochondrial hepatopathies (MHs) are primary mitochondrial genetic disorders that can present as childhood liver disease. No recognized biomarkers discriminate MH from other childhood liver diseases. The protein biomarkers growth differentiation factor 15 (GDF15) and fibroblast growth factor 21 (FGF21) differentiate mitochondrial myopathies from other myopathies. We evaluated these biomarkers to determine if they discriminate MH from other liver diseases in children.

METHODS

Serum biomarkers were measured in 36 children with MH (17 had a genetic diagnosis); 38 each with biliary atresia, α1-antitrypsin deficiency, and Alagille syndrome; 20 with NASH; and 186 controls.

RESULTS

GDF15 levels compared to controls were mildly elevated in patients with α1-antitrypsin deficiency, Alagille syndrome, and biliary atresia-young subgroup, but markedly elevated in MH (p<0.001). FGF21 levels were mildly elevated in NASH and markedly elevated in MH (p<0.001). Both biomarkers were higher in patients with MH with a known genetic cause but were similar in acute and chronic presentations. Both markers had a strong performance to identify MH with a molecular diagnosis with the AUC for GDF15 0.93±0.04 and for FGF21 0.90±0.06. Simultaneous elevation of both markers >98th percentile of controls identified genetically confirmed MH with a sensitivity of 88% and specificity of 96%. In MH, independent predictors of survival without requiring liver transplantation were international normalized ratio and either GDF15 or FGF21 levels, with levels <2000 ng/L predicting survival without liver transplantation (p<0.01).

CONCLUSIONS

GDF15 and FGF21 are significantly higher in children with MH compared to other childhood liver diseases and controls and, when combined, were predictive of MH and had prognostic implications.

Generation of an Alagille syndrome (ALGS) patient-derived induced pluripotent stem cell line (TRNDi032-A) carrying a heterozygous mutation (p.Cys682Leufs*7) in the JAG1 gene

Alagille syndrome (ALGS) is an autosomal dominant, multisystemic disorder due to haploinsufficiency in either the JAG1 gene (ALGS type 1) or the NOTCH2 gene (ALGS type 2). The disease has been difficult to diagnose and treat due to its muti-system clinical presentation, variable expressivity, and prenatal onset for some of the features. The generation of this iPSC line (TRNDi032-A) carrying a heterozygous mutation, p.Cys682Leufs*7 (c.2044dup), in the JAG1 gene provides a means of studying the disease and developing novel therapeutics towards patient treatment.

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.

Treatment of Cholestasis in Infants and Young Children

PURPOSE OF REVIEW

Cholestasis is characterized by a conjugated hyperbilirubinemia secondary to impaired bile synthesis, transport, or excretion from the liver. It is always pathologic and can be indicative of an underlying hepatobiliary, genetic, or metabolic disorder, several of which require timely diagnosis to ensure proper management and optimal outcomes. This review provides an overview of the evaluation of cholestasis with a focus on current and emerging treatment strategies.

RECENT FINDINGS

Increased accessibility of next generation sequencing (NGS) allows for utilization of genetic testing early in the diagnostic process. This may alter the clinical algorithm for diagnosis of cholestatic disorders. An enhanced understanding of the underlying pathophysiology may help guide future development of targeted therapies, such as ileal bile acid transporter (IBAT) inhibitors. These were recently approved for treatment of cholestatic pruritus in patients with Alagille syndrome and Progressive Familial Intrahepatic Cholestasis. Current management of cholestasis is aimed at the biochemical consequences of impaired bile flow, including malnutrition, pruritus, and progressive fibrosis. NGS has led to an enhanced understanding of biliary pathology and may guide development of future treatment modalities based on specific gene mutations. Rapid discernment of the underlying etiology is essential as new treatment modalities emerge.

The Curious Case of Alagille Syndrome: A Case Report With NANDA-I Classification, NIC, and NOC Linkage to the Patient Care Plan

Alagille syndrome is a rare and complex pleiotropic multisystem disorder caused by an autosomal dominant genetic mutation of JAG1 (90%) and NOTCH2 (1%-2%) genes located on the short arm of chromosome 20. This case is reported as per the CA se RE ports (CARE) guidelines (2013). A 14-year-old boy who is a known case of chronic cholestatic liver disease of neonatal onset, was diagnosed with Alagille syndrome as evident from a NOTCH 2 mutation in genetic analysis and paucity of intrahepatic bile ducts on biopsy. He presented with portal hypertension, growth failure, and persistent hyperbilirubinemia. This case highlights the gamut of multisystem dysfunctions faced by this child. He is currently on conservative management and worked up for liver transplantation. The condition is often rare and challenging due to the multisystem pathogenesis. Thus, the nursing care is also multifaceted. This case study identified relevant North American Nursing Diagnosis Association (NANDA) Classification, Nursing Interventions Classification (NIC), and Nursing Outcomes Classification (NOC) concepts to describe care of children with Alagille syndrome based on actual patient data.

Alagille syndrome: understanding the genotype-phenotype relationship and its potential therapeutic impact

INTRODUCTION

Alagille syndrome (ALGS) is an autosomal dominant, multisystem genetic disorder with wide phenotypic variability caused by mutations in the Notch signaling pathway, specifically from mutations in either the Jagged1 (JAG1) or NOTCH2 gene. The range of clinical features in ALGS can involve various organ systems including the liver, heart, eyes, skeleton, kidney, and vasculature. Despite the genetic mutations being well-defined, there is variable expressivity and individuals with the same mutation may have different clinical phenotypes.

AREAS COVERED

While no clear genotype-phenotype correlation has been identified in ALGS, this review will summarize what is currently known about the genotype-phenotype relationship and how this relationship influences the treatment of the multisystemic disorder. This review includes discussion of numerous studies which have focused on describing the genotype-phenotype relationship of different organ systems in ALGS as well as relevant basic science and population studies of ALGS. A thorough literature search was completed via the PubMed and National Library of Medicine GeneReviews databases including dates from 1969, when ALGS was first identified, to February 2023.

EXPERT OPINION

The genetics of ALGS are well defined; however, ongoing investigation to identify genotype-phenotype relationships as well as genetic modifiers as potential therapeutic targets is needed. Clinicians and patients alike would benefit from identification of a correlation to aid in diagnostic evaluation and management.

Health Care Resource Utilization by Patients with Alagille Syndrome

OBJECTIVE

To assess and characterize health care resource utilization (HRU) in children with the rare, genetic, multisystem disorder, Alagille syndrome.

STUDY DESIGN

This retrospective analysis reviewed commercially insured and Medicaid-insured claims from October 1, 2015 to December 31, 2019 to assess HRU in patients with Alagille syndrome. As there is no specific International Classification ofDiseases-10 code for Alagille syndrome, patients were identified using the following algorithm: ≥1 claim with diagnosis code Q44.7 (other congenital malformations of the liver); <18 years of age, with no history of biliary atresia (International Classification ofDiseases-10 code: Q44.2); and ≥6 months of insurance eligibility prior to diagnosis. HRU was summarized per patient per year over all available claims postdiagnosis.

RESULTS

A total of 171 commercially insured and 215 Medicaid-insured patients with Alagille syndrome were available for analysis. Annually, commercially insured and Medicaid-insured patients averaged 31 medical visits (range, 1.5-237) and 48 medical visits (range, 0.7-690), respectively. The most common visits were outpatient with the majority encompassing lab/imaging and primary care visits (commercially insured: 21 [range, 0.0-183]; Medicaid-insured: 26 [range, 0.0-609]). Inpatient visits were the highest driver of costs in both the commercial and Medicaid populations.

CONCLUSIONS

Patients with Alagille syndrome have a substantial HRU burden driven largely by numerous outpatient visits and costly inpatient stays. Given the complexity and variability of Alagille syndrome presentation, patients may benefit from multidisciplinary and subspecialized care.

Use of funded multicenter prospective longitudinal databases to inform clinical trials in rare diseases-Examination of cholestatic liver disease in Alagille syndrome

The conduct of long-term conventional randomized clinical trials in rare diseases is very difficult, making evidenced-based drug development problematic. As a result, real-world data/evidence are being used more frequently to assess new therapeutic approaches in orphan diseases. In this investigation, inclusion and exclusion criteria from a published trial of maralixibat in Alagille syndrome (ALGS, ITCH NCT02057692) were applied to a prospective longitudinal cohort of children with cholestasis (LOGIC NCT00571272) to derive contextual comparator data for evolving clinical trials of intestinal bile acid transport inhibitors in ALGS. A natural history/clinical care cohort of 59 participants who met adapted inclusion and exclusion criteria of ITCH was identified from 252 LOGIC participants with ALGS with their native liver. Frequency weighting was used to match the age distribution of ITCH and yielded a cohort (Alagille Syndrome Natural History [ALGS NH]) that was very similar to the baseline status of ITCH participants. During a 2-year prospective follow-up there was a significant reduction in pruritus in the weighted ALGS NH cohort as assessed by the clinician scratch score (-1.43 [0.28] -1.99, -0.87; mean [SEM] 95% confidence interval). During the same time period, the total bilirubin, albumin, and alanine aminotransferase levels were unchanged, whereas platelet count dropped significantly (-65.2 [16.2] -98.3, -32.1). Weighted survival with native liver was 91% at 2 years in the ALGS NH. These investigations provide valuable real-world data that can serve as contextual comparators to current clinical trials, especially those without control populations, and highlight the value and importance of funded multicenter, prospective, natural history studies.

An Adult Patient with Alagille Syndrome Showing Mainly Renal Failure and Vascular Abnormality without Liver Manifestation

Alagille syndrome is an inherited multisystemic disorder. We herein report an atypical case of a Japanese adult patient with Alagille syndrome. He had been diagnosed with Alagille syndrome as an infant based on a liver biopsy. At 27 years of age, he needed to start hemodialysis therapy, but an arteriovenous fistula was not created because his peripheral blood vessels were too narrow. He also had a recurrent brain infarction due to cerebral vascular stenosis. Alagille syndrome is generally recognized as a pediatric hepatic disease, but general physicians should be aware of its potential existence with renal involvement and vascular abnormalities.

Patient-specific modeling of right coronary circulation vulnerability post-liver transplant in Alagille's syndrome

OBJECTIVES

Cardiac output (CO) response to dobutamine can identify Alagille's syndrome (ALGS) patients at higher risk of cardiovascular complications during liver transplantation. We propose a novel patient-specific computational methodology to estimate the coronary autoregulatory responses during different hemodynamic conditions, including those experienced in a post-reperfusion syndrome (PRS), to aid cardiac risk-assessment.

MATERIAL AND METHODS

Data (pressure, flow, strain and ventricular volumes) from a 6-year-old ALGS patient undergoing catheter/dobutamine stress MRI (DSMRI) were used to parameterize a closed-loop coupled-multidomain (3D-0D) approach consisting of image-derived vascular models of pulmonary and systemic circulations and a series of 0D-lumped parameter networks (LPN) of the heart chambers and the distal arterial and venous circulations. A coronary microcirculation control model (CMCM) was designed to adjust the coronary resistance to match coronary blood flow (and thus oxygen delivery) with MVO2 requirements during Rest, Stress and a virtual PRS condition.

RESULTS

In all three simulated conditions, diastolic dominated right coronary artery (RCA) flow was observed, due to high right ventricle (RV) afterload. Despite a measured 45% increase in CO, impaired coronary flow reserve (CFR) (~1.4) at Stress was estimated by the CMCM. During modeled PRS, a marked vasodilatory response was insufficient to match RV myocardial oxygen requirements. Such exhaustion of the RCA autoregulatory response was not anticipated by the DSMRI study.

CONCLUSION

Impaired CFR undetected by DSMRI resulted in predicted myocardial ischemia in a computational model of PRS. This computational framework may identify ALGS patients at higher risk of complications during liver transplantation due to impaired coronary microvascular responses.

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.

Pathologic Features of Hereditary Cholestatic Diseases

The inherited diseases causing conjugated hyperbilirubinemia are diverse, with variability in clinical severity, histologic appearance, and time of onset. The liver biopsy appearances can also vary depending on whether the initial presentation is in the neonatal period or later. Although many of the disorders have specific histologic features in fully developed and classic cases, biopsies taken early in the disease course may be nonspecific, showing either cholestatic hepatitis or an obstructive pattern of injury requiring close correlation with the laboratory and clinical findings to reach the correct diagnosis. Additionally, increased understanding of the range of hepatic changes occurring in mild deficiencies of bile canalicular transporter proteins suggest that these disorders, particularly ABCB4 deficiency, may be more common than previously recognized; improved awareness should prompt further investigation.

Alagille Syndrome Mimicking Biliary Atresia in Early Infancy

Alagille syndrome may mimic biliary atresia in early infancy. Since mutations in JAG1 typical for Alagille syndrome type 1 have also been found in biliary atresia, we aimed to identify JAG1 mutations in newborns with proven biliary atresia (n = 72). Five biliary atresia patients with cholestasis, one additional characteristic feature of Alagille syndrome and ambiguous liver histology were single heterozygotes for nonsense or frameshift mutations in JAG1. No mutations were found in the remaining 67 patients. All "biliary atresia" carriers of JAG1 null mutations developed typical Alagille syndrome at the age of three years. Our data do not support association of biliary atresia with JAG1 mutations, at least in Czech patients. Rapid testing for JAG1 mutations could prevent misdiagnosis of Alagille syndrome in early infancy and improve their outcome.

JAGGED1 gene variations in Chinese twin sisters with Alagille syndrome

Variations in the JAGGED1 gene have been found to cause Alagille syndrome. Nevertheless, no particular hotspots in the gene have been found; any part of the entire coding regions for JAGGED1 may be involved. Twin sisters with jaundice visited our hospital and were diagnosed with Alagille syndrome. The gene variations in their JAGGED1 coding sequences were evaluated by complementary DNA sequencing. The 12-month-old twin sisters have broad foreheads, deep-set eyes, pointed chins, and triangular faces with jaundice. Clinical testing showed the presence of posterior embryotoxon, butterfly vertebrae, and atrial septal defect. Biochemical indexes showed cholestasis and liver damage. Three conserved variations were identified within exons 22 (c.2612C>G), 24 (c.2957T>A), and 26 (c.3417T>C) in the JAGGED1 coding sequence. The predicted consequences for c.2612C>G, c.2957T>A, and c.3417T>C were p.Pro871Arg, p.Leu986*, and p.Tyr1139=, respectively. The T to A change in the JAGGED1 coding sequence at 2957 will generate a stop codon and might lead to deletion of amino acid 233 at the C terminal of the JAGGED1 protein. Our data suggest that gene variations of c.2612C>G, c.2957T>A, and c.3417T>C, especially c.2957T>A, might have contributed to the pathogenesis of Alagille syndrome in these Chinese twin sisters and provided new gene evidences for Alagille syndrome.

Alagille syndrome with a previously undescribed mutation

BACKGROUND

Alagille Syndrome is a rare genetic disease characterized by abnormalities of the intrahepatic biliary ducts with cholestasis along with multisystem anomalies.

CASE CHARACTERISTICS

An 8-year old child with persisting jaundice, severe itching and failure to thrive.

OBSERVATION

Diagnosis of Alagille syndrome was made on the basis of clinical features, typical facies and liver biopsy showing bile duct paucity. Genetic analysis revealed a novel de novo mutation in the JAG 1 gene.

OUTCOME

The child was started on ursodeoxycholic acid following which the itching improved.

MESSAGE

A novel de novo mutation in JAG 1 gene is described in this child with Alagille Syndrome.

A Chinese girl molecularly diagnosed with Alagille syndrome

BACKGROUND

Alagille syndrome (AGS) is a rare or fatal disease affecting multiple systems including the liver, heart, eyes, skeleton and face. It has been considered a genetically heterogeneous disorder of the Notch signaling pathway.

METHODS

A 28-month-old Chinese girl with congenital heart disease and jaundice was diagnosed with Alagille syndrome by liver biopsy showing a paucity of the intrahepatic bile ducts. Variants of the JAG1 gene were detected by DNA sequencing in the patient and her unaffected father.

RESULTS

A heterozygous missense mutation was identified in exon 2 of the JAG1 gene in the proband but not in exon 2, 4, 6, 9, 17, 23, 24 by DNA sequencing in her father. The mutation G-->T change was seen at position 133 in the cDNA sequence (c.133 G-->T), causing a substitution of a leucine for a valine (V45L) residue in the N terminus between signal peptide and DSL domain of the Notch ligand. This mutation, however, was absent in her father.

CONCLUSION

Genes in the Notch signaling pathway should be further studied in AGS, and used to confirm clinical or prenatal diagnosis and facilitate genetic counseling.

Renal abnormalities in a family with Alagille syndrome

Alagille syndrome is largely unknown to the general internist because the diagnosis is usually made by a paediatrician. Nevertheless, it is important to be aware of this syndrome because it sometimes manifests later in life with a great variability in clinical presentation and important consequences for the individual patient. We therefore discuss this syndrome using a patient with the usual characteristics of this syndrome.

Advantages of multiple markers and polar body analysis in preimplantation genetic diagnosis for Alagille disease

OBJECTIVE

The development of a preimplantation genetic diagnosis (PGD) protocol for Alagille syndrome (AGS), a rare autosomal dominant disorder with hepatic, cardiac and ophthalmologic involvement.

METHODS

We developed a polar body (PB)-based multiplex fluorescent PCR reaction for a female affected with AGS. The protocol included analysis of the Jagged 1 (JAG1) familial mutation and five closely linked highly polymorphic markers (D20S162, D20S901, D20S894, and D20S186).

RESULTS

In two cycles of PGD 9 of ten embryos were accurately diagnosed by assessment of first and second PBs, one embryo required additional blastomere biopsy.

CONCLUSIONS

This protocol takes advantage of the larger window of opportunity for transfer and the increased accuracy of diagnosis afforded by the combination of PB biopsy and multiple marker analysis. Two cycles resulted in the transfer of two and three mutation-free embryos and a subsequent pregnancy as measured by the rising hCG levels.

Alagille syndrome in adult patients: it is never too late

Alagille syndrome (AGS; Online Mendelian Inheritance in Man no. 118450) is a multisystem autosomal dominant disorder with highly variable expression characterized by chronic cholestasis caused by a paucity of interlobular bile ducts, skeletal abnormalities, peculiar facies, ocular abnormalities, and cardiovascular disorders. AGS is diagnosed almost exclusively in children in the setting of predominant liver manifestations or, more rarely, in their adult relatives. We report 2 patients in whom AGS was diagnosed in adulthood during the workup of renal disease in the absence of a well-defined familial history. Renal disease caused by AGS probably is underdiagnosed in adult patients.

Prenatal molecular diagnosis of inherited cholestatic diseases

OBJECTIVES

Progressive familial intrahepatic cholestasis (PFIC) and to a lesser extent, Alagille syndrome, often lead to end-stage liver disease during childhood. We report our experience of DNA-based prenatal diagnosis of PFIC1-3 and Alagille syndrome.

PATIENTS AND METHODS

Four molecular antenatal diagnoses were performed in 3 PFIC families and 17 in 11 Alagille syndrome families. DNA was isolated from chorionic villus or cultured amniocyte samples from women, without pregnancy complications.

RESULTS

All four foetuses with a family history of PFIC1, 2, or 3 were heterozygous for an ATP8B1, ABCB11, or ABCB4 mutation and pregnancies were continued. Three of the infants were healthy after birth, and 1 premature infant, who had an ABCB4 mutation, experienced transient neonatal cholestasis. Among the families with a history of de novo JAG1 mutation, none of the foetuses was mutated, versus 40% of those with a history of familial mutation. Of 4 pregnant women with a JAG1-mutated foetus, 3 cut short their pregnancy and 1 gave birth to a child with overt Alagille syndrome.

CONCLUSIONS

Molecular antenatal diagnosis of PFIC1-3 and Alagille syndrome is reliable because clinical outcome after birth corresponded to molecular foetal data.

Jagged1 (JAG1) mutations in Alagille syndrome: increasing the mutation detection rate

Alagille syndrome (AGS) is caused by heterozygous mutations in JAG1, and mutations have been previously reported in about 70% of patients who meet clinical diagnostic criteria. We studied a cohort of 247 clinically well-defined patients, and using an aggressive and sequential screening approach we identified JAG1 mutations in 94% of individuals. Mutations were found in 232 out of 247 patients studied and 83 of the mutations were novel. This increase in the mutation rate was accomplished by combining rigorous clinical phenotyping, with a combination of mutation detection techniques, including fluorescence in situ hybridization (FISH), genomic and cDNA sequencing, and quantitative PCR. This higher rate of mutation identification has implications for clinical practice, facilitating genetic counseling, prenatal diagnosis, and evaluation of living-related liver transplant donors. Our results suggest that more aggressive screening may similarly increase the rate of mutation detection in other dominant and recessive disorders.

Alagille syndrome and optic pit

BACKGROUND

Optic disc anomalies are frequently associated with Alagille syndrome. We report here the first case of a patient with Alagille syndrome combined with optic pit and serous macular detachment.

METHODS

A male patient with Alagille syndrome was referred from the pediatric hepatology department for investigation of visual loss in the right eye. Anterior segment examination showed evidence of posterior embryotoxon, confirmed by gonioscopic evaluation. Dilated fundus examination revealed serous macular detachment and optic pit.

RESULTS

OCT 3 scans confirmed the clinical findings.

CONCLUSIONS

Optic pit is uncommon and should prompt a search for genetic disorders or development abnormalities. The association between the two syndromes in this patient might be due to failure of correct neuroectodermal development, for which a common genetic pathway is likely.

Biliary hypoplasia in Williams syndrome

Neonatal hepatitis and biliary hypoplasia are not recognised features of Williams syndrome. A case of Williams syndrome, presenting with neonatal conjugated hyperbilirubinaemia leading to an initial misdiagnosis is reported.

Liver transplantation in children with Alagille syndrome: indications and outcome

An AGS is a dominant inherited multisystem disorder caused by mutations in the Notch signaling pathway (JAG1). In our center, 5.3% of liver transplantations (OLT) are performed in children with AGS. Some of the affected children fulfilled criteria for OLT, despite the absence of liver cirrhosis. The aim of our present study was to evaluate the indications and outcome for OLT in children with this complex disorder as clear criteria are difficult to establish in clinical practice. A total of 37 patients were included in a retrospective analysis. Twenty-four children underwent OLT for chronic end-stage liver failure (n = 8) or symptomatic liver disease (n = 16). Patient survival post-OLT was 91.7% after 1 yr, that of graft survival was 87.5%, respectively. Significant post-transplant vascular complications included a mid-aortic syndrome (n = 1) and severe lethal bleeding due to suspected vascular malformation (n = 1). Severe hypercholesterolemia (>800 mg/dL) and xanthomata resolved completely in affected patients. We conclude from our data that indications for OLT in AGS should be extended to patients with severe symptomatic liver disease, even in the absence of liver cirrhosis because of the significantly improved outcome after pediatric OLT in the last decade. Future studies must identify underlying mechanisms of hypercholesterolemia and vascular malformation.

Case report: Alagille syndrome

The clinical case of a boy aged 6 years suffering from Alagille syndrome is described. This is a rare genetic disease characterised, from the hepatic point of view, by anomalies of the intrahepatic biliary ducts (in terms of number, histology and immunohistochemistry) with cholestasis; from the systemic point of view it is characterised by anomalies of various systems (heart, musculoskeletal system, eyes, face, kidneys and nervous system). The patient was referred for dental consultation by the Pediatric Cardiology Section, Sant'Orsola-Malpighi Polyclinic, Bologna City Hospital. Medical history indicated liver transplantation at 3 years; immunosuppressive treatment; heart disease with low risk of bacterial endocarditis (interventricular defect and systolic murmur). Objective examination revealed a dental formula compatible with his age, of a decided green colour (above all the permanent dentition) with numerous caries lesions on the posterior deciduous teeth. In agreeing the treatment plan with the cardiologist (treatment of caries and sealing the fissures and cracks in the permanent first molars) it was decided that antibiotic prophylaxis was not required since such conservative treatment is not at risk for bacterial endocarditis. The patient returned 15 min after the end of the second session with marked swelling of the right upper hemi-lip. Having excluded traumatic origin, a hypothesis was formulated of hypersensitivity to products used during the dental session, in particular talcum-coated gloves and latex rubber dam. The patient was referred immediately to the Dermatology Service, Sant'Orsola-Malpighi Polyclinic, for the appropriate dermatological tests (prick test and epicutaneous test) which confirmed the suspected diagnosis: urticaria from contact with latex materials. The clinical case described confirms the need for the dentist of an interdisciplinary approach in patients suffering from systemic diseases and/or syndromes.

A case of Takayasu disease with findings of incomplete Alagille syndrome

A 16-year-old girl being followed up for Takayasu arteritis for the last 3 years was also found to have Alagille syndrome upon findings of atypical facies, posterior embryotoxon, high-pitched voice, osteopenia and hypogonadism. This case might imply a possible relationship between Takayasu arteritis and Alagille syndrome.

Alagille syndrome with prominent skin manifestations

Alagille syndrome, a rare genetic disorder with autosomal dominant transmission, manifests 5 major features: paucity of interlobular bile ducts, characteristic facies, posterior embryotoxon, vertebral defects and peripheral pulmonic stenosis. We report a 6-year-old male child who presented with a history of progressive jaundice since infancy, generalized pruritus and widespread cutaneous xanthomata. He was also found to have obstructive jaundice, pulmonary stenosis with ventricular septal defect and paucity of bile ducts in liver biopsy. Histopathology confirmed skin lesions as xanthomata. The child was diagnosed as a case of Alagille syndrome. This particular syndrome with prominent cutaneous manifestations has been rarely reported in the Indian literature.

Scintigraphic progress of the liver in a patient with Alagille syndrome (arteriohepatic dysplasia)

We encountered a 9-year-old Japanese girl with Alagille syndrome. Her scintigraphic examinations of the liver were performed at the ages of 16 months and 9 years. 99mTc-PMT, a hepatobiliary imaging agent, was distributed homogeneously in the liver at the younger age, but unevenly produced an area of focally increased uptake in the medial segment of the liver surrounded by peripheral atrophy at the older age. 99mTc-GSA, a hepatoreceptor binding agent, was highly accumulated in the area, corresponding to the focally increased uptake of 99mTc-PMT. These imaging findings suggest that the pathophysiological and morphological changes of the liver occurred in our patient during the clinical course.

Consequences of JAG1 mutations

BACKGROUND

Alagille syndrome (AGS) is a multi-system, autosomal dominant disorder with highly variable expressivity, caused by mutations within the Jagged1 (JAG1) gene.

METHODS

We studied 53 mutation positive relatives of 34 AGS probands to ascertain the frequency of clinical findings in JAG1 mutation carriers.

RESULTS

Eleven of 53 (21%) mutation positive relatives had clinical features that would have led to a diagnosis of AGS. Seventeen of the 53 (32%) relatives had mild features of AGS, revealed only after targeted evaluation following the diagnosis of a proband in their family. Twenty five of the 53 (47%) mutation positive relatives did not meet clinical criteria, and two of these individuals had no features consistent with AGS at all. The frequency of cardiac and liver disease was notably lower in the relatives than in the probands, characterising the milder end of the phenotypic spectrum. The characteristic facies of AGS was the feature with the highest penetrance, occurring almost universally in mutation positive probands and relatives.

CONCLUSIONS

This study has implications for genetic counselling of families with AGS and JAG1 mutations.

Clinical problems with developmental anomalies of the biliary tract

Cholestatic jaundice defined as conjugated hyperbilirubinemia is a typical feature of neonatal liver disease. Biliary atresia is the most common disorder producing cholestasis during the first 2 months of life. Syndromic and non-syndromic paucity of the intralobular bile ducts and choledochal cysts can also present with cholestasis during early life. Liver dysfunction from obstruction of the biliary tree must be differentiated from numerous disorders affecting hepatocytes such as congenital infection and inborn errors of metabolism. Early recognition and a stepwise diagnostic evaluation of the cholestatic infant are essential in successfully treating many metabolic and infectious liver diseases of the infant as well as surgically relieving obstruction in patients with biliary atresia.

Heritable disorders of the bile ducts

Diseases of the bile ducts encompass a wide range of disorders. These include those disorders primarily affecting extra and intrahepatic bile ducts and those that may be classified as panbiliary. The major heritable bile duct disorders are those affecting the intrahepatic ducts, namely syndromic bile duct paucity, or Alagille syndrome, and the fibrocystic cholangiopathies autosomal recessive polycystic kidney disease/congenital hepatic fibrosis, and autosomal dominant polycystic kidney disease. This discussion focuses on heritable disorders of the bile ducts.

[Alagille syndrome and chronic renal failure]

Alagille syndrome is characterized by paucity of bile ducts leading to cholestasis and may be accompanied by renal and cardiovascular abnormalities. We report 42-years old patient with hypertension, chronic renal failure and Alagille syndrome. Ischemic nephropathy was suspected, which was not confirmed on angio-CT. It seems, that chronic renal failure in the patient was due to primary parenchymal pathology.

Craniosynostosis in Alagille syndrome

Alagille syndrome is a multisystem developmental disorder with primary involvement of the liver, heart, skeleton, eyes and facial structures, and demonstrates highly variable expressivity with respect to all of the involved systems. Alagille syndrome is caused by mutations in the Jagged1 gene. Jagged1 is a ligand in the Notch signaling pathway that has been shown to regulate early cell fate determination. Mutations in Jagged1 have been identified in approximately 80% of patients with Alagille syndrome. We have recently identified two patients with mutation proven Alagille syndrome who also had unilateral coronal craniosynostosis. Both individuals were screened for mutations in fibroblast growth factor receptor 1, 2, 3 and TWIST genes, all associated with various types of craniosynostosis and no mutations were identified. The finding of a conserved form of craniosynostosis in two unrelated patients with Alagille syndrome and mutations in Jagged1 may indicate that Jagged1 plays a role in cranial suture formation.

Analysis of cardiovascular phenotype and genotype-phenotype correlation in individuals with a JAG1 mutation and/or Alagille syndrome

BACKGROUND

Cardiovascular anomalies are among the most common features of Alagille syndrome (AGS). Mutations of JAG1 are found in most individuals with AGS. This study was undertaken to determine the spectrum of cardiovascular phenotypes associated with a JAG1 mutation and/or AGS, investigate potential genotype-phenotype correlations, and begin to correlate clinical outcome with genetic pathogenesis.

METHODS AND RESULTS

We reviewed the records of 200 individuals with a JAG1 mutation or AGS. A total of 187 (94%) subjects had evidence of cardiovascular involvement. Cardiovascular anomalies were identified by imaging in 150 subjects (75%), and 37 (19%) had a peripheral pulmonary stenosis murmur with either a normal echocardiogram or no imaging study. Of the 150 subjects with anomalies confirmed by imaging, right-sided anomalies were present in 123 and left-sided anomalies in 22, with both in 12. Seventeen subjects had other anomalies. The most common abnormality was stenosis/hypoplasia of the branch pulmonary arteries (PAs), which was documented by imaging (n=111) or inferred from a peripheral pulmonary stenosis murmur (n=41) in 76% of subjects. Tetralogy of Fallot was present in 23 subjects and was accompanied by pulmonary atresia in 8. Branch PA phenotype differed between individuals with and without a JAG1 mutation. Among subjects with a JAG1 mutation, there was no correlation between the type or location of mutation and the frequency or type of cardiovascular anomaly.

CONCLUSIONS

More than 90% of individuals with a JAG1 mutation or AGS have cardiovascular anomalies, with branch PA stenosis the most common abnormality. Cardiovascular phenotype does not correlate with the type or location of JAG1 mutation.

Alagille syndrome

Alagille syndrome (AGS) was described more than 35 years ago as a genetic entity characterised by five major features: chronic cholestasis owing to paucity of interlobular bile ducts; peripheral pulmonary stenosis; butterfly like vertebral arch defect; posterior embryotoxon and peculiar facies. AGS has long been said to have a relative good prognosis but overall survival at twenty years averages 70%. Complex congenital heart disease and hepatic disease with or without liver transplantation contribute significantly to mortality. JAGGED1 has been identified as a responsible gene by demonstration of mutations in AGS patients. Studies of JAGGED1 expression pattern demonstrate that minor features and almost all the elements in the long list of manifestations described in AGS patients are not coincidental. This suggests that Alagille syndrome definition may be revisited in the light of JAGGED1 mutations.

Alagille syndrome

Syndromic paucity of bile ducts or "Alagille syndrome" is characterized by peculiar facies, chronic cholestasis, posterior embryotoxon, butterfly-like vertebral arch defects and peripheral pulmonary artery hypoplasia or stenosis. We present a two-year-old female child with the 'partial' or 'incomplete' Alagille syndrome. The child had three of the five major features of the syndrome. A brief review of literature of the syndrome is presented.