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Background: Patients with the Crigler-Najjar syndrome lack the enzyme uridine diphosphoglucuronate glucuronosyltransferase 1A1 (UGT1A1), the absence of which leads to severe unconjugated hyperbilirubinemia that can cause irreversible neurologic injury and death. Prolonged, daily phototherapy partially controls the jaundice, but the only definitive cure is liver transplantation., Methods: We report the results of the dose-escalation portion of a phase 1-2 study evaluating the safety and efficacy of a single intravenous infusion of an adeno-associated virus serotype 8 vector encoding UGT1A1 in patients with the Crigler-Najjar syndrome that was being treated with phototherapy. Five patients received a single infusion of the gene construct (GNT0003): two received 2×10 12 vector genomes (vg) per kilogram of body weight, and three received 5×10 12 vg per kilogram. The primary end points were measures of safety and efficacy; efficacy was defined as a serum bilirubin level of 300 μmol per liter or lower measured at 17 weeks, 1 week after discontinuation of phototherapy., Results: No serious adverse events were reported. The most common adverse events were headache and alterations in liver-enzyme levels. Alanine aminotransferase increased to levels above the upper limit of the normal range in four patients, a finding potentially related to an immune response against the infused vector; these patients were treated with a course of glucocorticoids. By week 16, serum bilirubin levels in patients who received the lower dose of GNT0003 exceeded 300 μmol per liter. The patients who received the higher dose had bilirubin levels below 300 μmol per liter in the absence of phototherapy at the end of follow-up (mean [±SD] baseline bilirubin level, 351±56 μmol per liter; mean level at the final follow-up visit [week 78 in two patients and week 80 in the other], 149±33 μmol per liter)., Conclusions: No serious adverse events were reported in patients treated with the gene-therapy vector GNT0003 in this small study. Patients who received the higher dose had a decrease in bilirubin levels and were not receiving phototherapy at least 78 weeks after vector administration. (Funded by Genethon and others; ClinicalTrials.gov number, NCT03466463.)., (Copyright © 2023 Massachusetts Medical Society.)

Aim: To evaluate the role of diffusion tensor imaging of the auditory pathway in patients with Crigler Najjar syndrome type I and its relation to auditory brainstem response., Methods: Prospective study was done including 12 patients with Crigler Najjar syndrome type I and 10 age- and sex-matched controls that underwent diffusion tensor imaging of brain. Mean diffusivity and fractional anisotropy at 4 regions of the brain and brainstem on each side were measured and correlated with the results of auditory brainstem response for patients., Results: There was significantly higher mean diffusivity of cochlear nucleus, superior olivary nucleus, inferior colliculus, and auditory cortex of patients versus controls on both sides for all regions ( P = .001). The fractional anisotropy of cochlear nucleus, superior olivary nucleus, inferior colliculus, and auditory cortex of patients versus controls was significantly lower, with P values of, respectively, .001, .001, .003, and .001 on the right side and .001, .001, .003, and .001 on left side, respectively. Also, a negative correlation was found between the maximum bilirubin level and fractional anisotropy of the left superior olivary nucleus and inferior colliculus of both sides. A positive correlation was found between the mean diffusivity and auditory brainstem response wave latency of the right inferior colliculus and left cochlear nucleus. The fractional anisotropy and auditory brainstem response wave latency of the right superior olivary nucleus, left cochlear nucleus, and inferior colliculus of both sides were negatively correlated., Conclusion: Diffusion tensor imaging can detect microstructural changes in the auditory pathway in Crigler Najjar syndrome type I that can be correlated with auditory brainstem response.

Introduction: Crigler Najjar (CN) disease is a genetic disorder which results in increased unconjugated bilirubin level. Liver parenchyma was previously considered structurally normal. Recent reports describe significant fibrosis in the liver parenchyma of patients with CN syndrome., Case Report: We present a patient with persistent unconjugated hyperbilirubinemia, clinically diagnosed as CN-2, with a UGT1 A1 p. H39D (c.115C > G) (His → Asp) mutation. She required hepatic transplantation at the age of 17.5 years for biliary cirrhosis. Explanted liver histopathology revealed regenerative cirrhotic nodules with dilated bile ducts filled with bile plugs., Conclusion: CN can develop significant hepatic fibrosis/cirrhosis requiring liver transplantation.

Background: Crigler-Najjar syndrome (CN) is a very rare genetic disorder characterized by an inability to conjugate bilirubin. Contrary to CN type I, patients with CN II exhibit residual capacity to conjugate bilirubin and may present a normal life expectancy., Case Presentation: We report an unusual late diagnosis of CN type II in an 80-year-old female admitted with severe acute cholangitis. While the patient present typical clinical and radiologic signs of bile duct obstruction and cholangitis, her blood analysis showed severe unconjugated hyperbilirubinemia. Endoscopic retrograde cholangiopancreatography confirmed the diagnosis and allowed therapeutic intervention. The anatomopathologic examination of her gallbladder following cholecystectomy showed signs of chronic cholecystitis., Conclusion: The risk of gallstone disease may be increased in patients with CN syndrome. While unusual, we alert to this curious and potential life-threatening presentation.

X-linked ichthyosis (XLI) is an X-linked recessive skin disorder generally restricted to males, which arises from mutations in the steroid sulfatase (STS) gene located on Xp22.3. Crigler-Najjar syndrome (CN-I) is a rare autosomal recessive disease caused by the homozygous or compound heterozygous mutations in the UPD‑glucuronosyltransferase 1 family, polypeptide A1 (UGT1A1) gene on chromosome 2q37. A male patient was referred to the Department of Medical Genetics with of severe icterus and ichthyosis. The patient and his family members underwent genetic tests related to XLI and CN-I. Quantitative polymerase chain reaction on genomic DNA was performed to determine the gene copy number, while single nucleotide polymorphism array analysis was conducted to identify deletion mutations. Family pedigree analysis showed that the patient and his two cousins were all affected by ichthyosis, which was in accordance with the inheritance pattern of an X-linked recessive disease. In addition, the patient's serum bilirubin concentration (>340 mmol/l) was markedly greater than the normal level. The patient presented with kernicterus and phenobarbital treatment was ineffective. The clinical diagnosis of XLI was confirmed molecularly by laboratory evidence of a maternal 1.61 M deletion (including the STS gene) on ChrXp22.31. Coincidentally, the male patient was also confirmed to carry a rare maternal inherited microdeletion (374 Kb) comprising the entire UGT1A1 gene combined with a paternal UGT1A1 mutation (c.1253delT), a causative event of CN-I. To the best of our knowledge, this study reported for the first time the comorbidity of XLI and CN-I in a male patient. The results suggested that co-occurrence of these two recessive diseases in a patient may be incidental.

We describe an infant who was readmitted from home at 14 days of age with jaundice and a history of apnoea and episodes of retrocollis/opisthotonos. He had been only mildly jaundiced on discharge from the maternity clinic at 2 days of age. The total serum bilirubin (TSB) on admission was 542 µmol/L, and the infant was treated intensively with triple phototherapy and exchange transfusion. In contrast to what is recommended in Norwegian national guidelines for management of neonatal jaundice, the parents had apparently neither received oral nor written information about jaundice and its follow-up at the time of discharge from maternity. They therefore contacted their child healthcare centre when they had questions about jaundice, though the national guidelines specifically state that follow-up for neonatal jaundice during the first 2 weeks of life is the responsibility of the birth hospital. Inappropriate advice resulted in delayed referral, and the child has been diagnosed with chronic kernicterus, probably the first such case in Norway since national guidelines were formalised in 2006. Genetic work-up disclosed compound heterozygosity for Crigler-Najjar syndrome type I, to the best of our knowledge the first instance of this disorder ever to have been diagnosed in Norway. The incidence of kernicterus is Norway is much lower than in other industrialised countries. This is most likely due to national guidelines for management of neonatal jaundice, which place the responsibility for management and follow-up of jaundice with the birth hospital during the crucial first 2 weeks of life. This case report reminds us that tragedies may occur when guidelines are disregarded.

A seven-day-old, mature girl was hospitalized with serum unconjugated bilirubin 420 micromol/l. She was treated with phototherapy, which continued at home until the age of 14 years. Serum total bilirubin was then 250-300 micromol/l and she received a liver transplantation. At the age of 22 years she had no signs of chronic bilirubin encephalopathy. There was no activity of bilirubin UDP-glucuronosyl transferase in the liver, and a mutation was found in one of the coding exons in the gene. The girl suffered from Crigler-Najjar's syndrome type 1. In Denmark the incidence was about 2.7 × 10-6 in the period 1977-2010. The prevalence was about 0.5 × 10-6.

Crigler-Najjar type 1 is a rare congenital disease caused by total lack of activity of bilirubin uridine diphosphate glucuronosyl transferase (UGT1A1) in the liver. The disease is characterised by a persistent severe unconjugated hyperbilirubinaemia. The primary treatment is phototherapy, with oral calcium phosphate as a possible supplementation. The effect of the treatment decreases by age, and if the phototherapy is insufficient the patient will need a liver transplantation. Hepatocyte transplantation has been tried with transient success. The risk of chronic bilirubin encephalopathy is considerable.

Crigler-Najjar syndrome type I is an autosomal recessive inherited disease and rarely seen in childhood. Bilirubin neurotoxicity is the morbidity of the disease due to the elevated unconjugated bilirubin levels. Mental retardation, seizures, cognitive dysfunction, oculomotor nerve palsy, ataxia, choreoathetosis, and spasticity may be seen. Due to the high bilirubin levels, alterations in the neurophysiological studies may be detected. In this study, we describe two siblings who were diagnosed with Crigler-Najjar syndrome type I who underwent a successful liver transplantation using a single cadaveric organ, together with their neurophysiological follow-up and review of the literature.

Pheochromocytoma is a rare disease in the general population and, to the best of our knowledge, only one case has been reported so far in patients with hemoglobinopathies. We describe the occurrence of pheochromocytoma in a patient with thalassemia intermedia associated with Gilbert's disease and Crigler- Najjar Type 2 syndrome.

Crigler-Najjar (CN) syndrome is a rare genetic disease characterized by hyperbilirubinemia due to a deficiency in the hepatic enzyme UDP-glucuronosyl-transferase. We describe the first case of total knee arthroplasty in a patient with CN syndrome (type II). This procedure was complicated by kernicterus 1 week after hospital discharge. He also developed Klebsiella bacteremia and sepsis, requiring a brief ICU stay. He was discharged in good condition 2 months later. It is evident that physicians involved in the care of patients with CN syndrome in the peri-operative period need to have a high index of suspicion for the development of severe hyperbilirubinemia and kernicterus in order to appropriately manage and, possibly, prevent this complication. A literature review and intra-operative observations provide insight into the possible relationship between hyperbilirubinemia and osteoarthritis as well as the peri-operative considerations to be made for this group of patients.

Clinically apparent jaundice is unusual in patients with beta-thalassemia major. Co-inheritance of Gilbert syndrome has been reported to cause hyperbilirubinemia in these subjects. Crigler-Najjar syndrome is another rare disorder of bilirubin metabolism caused by mutation in the gene coding the enzyme UGT1A1. We report a patient of beta-thalassemia major who presented with persistent jaundice due to co-inherited Crigler-Najjar syndrome type 2 secondary to a novel mutation in UGT1A1 gene [homozygous base substitution at position 362 (GGT>AGT) in exon 3].

Patients with Crigler-Najjar Type 1 (CN-1) disorder have an unconjugated hyperbilirubinaemia due to the complete absence in activity of uridinediphosphate glucuronosyltransferase, a bilirubin-conjugating enzyme. In pregnant women with CN-1, the foetus is at high risk of being adversely affected by the bilirubin, as unconjugated bilirubin can cross the placenta and is potentially neurotoxic. We report the long-term outcomes of two infants born to women with CN-1. These infants had exchange transfusions soon after birth and have normal neurodevelopmental outcomes at 18 months and four years of age, respectively. We propose that this intervention might have improved the neurological outcome of these infants.

Background/aims: Conditionally immortalized hepatocytes offer a renewable source of hepatocytes, but although preparative maneuvers have been developed for hepatic repopulation with primary hepatocytes, extensive proliferation of transplanted immortalized hepatocytes has not been accomplished heretofore. Our aim was to achieve ex vivo gene therapy of uridinediphosphoglucuronate glucuronosyltransferase-1A1 (UGT1A1)-deficient jaundiced Gunn rats (model of Crigler-Najjar syndrome type-1) by hepatic repopulation with genetically modified and conditionally immortalized hepatocytes., Methods: Gunn rat hepatocytes were conditionally immortalized by stable transduction with a thermolabile mutant simian virus 40 T-antigen ((ts)Tag(A58)) and further transduced with UGT1A1. These hepatocytes proliferate at 33 degrees C, but at 37 degrees C the (ts)Tag(A58) is degraded and the cells become quiescent. The cells were transplanted into Gunn rat livers after preparative hepatic irradiation (50 Gy) and 66% hepatectomy., Results: The engrafted UGT1A1-positive immortalized hepatocytes replaced approximately 80% of the host hepatocytes in 20 weeks, leading to normalization of hyperbilirubinemia. Liver histology, and serum albumin and alanine aminotransferase levels remained normal., Conclusions: We achieved complete cure of hyperbilirubinemia in Gunn rats by ex vivo gene therapy via genetically modified and conditionally immortalized hepatocytes.

We summarize the treatment of 20 patients with Crigler-Najjar disease (CND) managed at one center from 1989 to 2005 (200 patient-years). Diagnosis was confirmed by sequencing the UGTA1A gene. Nineteen patients had a severe (type 1) phenotype. Major treatment goals were to maintain the bilirubin to albumin concentration ratio at <0.5 in neonates and <0.7 in older children and adults, to avoid drugs known to displace bilirubin from albumin, and to manage temporary exacerbations of hyperbilirubinemia caused by illness or gallstones. A variety of phototherapy systems provided high irradiance over a large body surface. Mean total bilirubin for the group was 16+/-5 mg/dl and increased with age by approximately 0.8 mg/dl per year. The molar ratio of bilirubin to albumin ranged from 0.17 to 0.75 (mean: 0.44). The overall non-surgical hospitalization rate was 0.12 hospitalizations per patient per year; one-half of these were for neonatal hyperbilirubinemia and the remainder were for infectious illnesses. Ten patients (50%) underwent elective laproscopic cholecystectomy for cholelithiasis. No patient required invasive bilirubin removal or developed bilirubin-induced neurological damage under our care. Visual acuity and color discrimination did not differ between CND patients and age-matched sibling controls. Four patients treated with orthotopic liver transplantation were effectively cured of CND, although one suffered significant transplant-related complications.Conclusions. While patients await liver transplantation for CND, hyperbilirubinemia can be managed safely and effectively to prevent kernicterus. Lessons learned from CND can be applied to screening and therapy of non-hemolytic jaundice in otherwise healthy newborns.

Background: In living donor liver transplantation (LDLT), the liver donor is almost always a blood relative; therefore, the donor is sometimes a heterozygous carrier of inheritable diseases. The use of such carriers as donors has not been validated. The aim of the present study was to evaluate the outcome of LDLT for noncirrhotic inheritable metabolic liver disease (NCIMLD) to clarify the effects of using a heterozygous carrier as a donor., Methods: Between June 1990 and December 2003, 21 patients with NCIMLD underwent LDLT at our institution. The indications for LDLT included type II citrullinemia (n = 7), ornithine transcarbamylase deficiency (n = 6), propionic acidemia (n = 3), Crigler-Najjar syndrome type I (n = 2), methylmalonic acidemia (n = 2), and familial amyloid polyneuropathy (n = 1). Of these 21 recipients, six underwent auxiliary partial orthotopic liver transplantation., Results: The cumulative survival rate of the recipients was 85.7% at both 1 and 5 years after operation. All surviving recipients are currently doing well without sequelae of the original diseases, including neurological impairments or physical growth retardation. Twelve of the 21 donors were considered to be heterozygous carriers based on the modes of inheritance of the recipients' diseases and preoperative donor medical examinations. All donors were uneventfully discharged from the hospital and have been doing well since discharge. No mortality or morbidity related to the use of heterozygous donors was observed in donors or recipients., Conclusions: Our results suggest that the use of heterozygous donors in LDLT for NCIMLD has no negative impact on either donors or recipients, although some issues remain unsolved and should be evaluated in further studies.

Crigler-Najjar syndrome type I is an autosomal recessive disorder with severe unconjugated hyperbilirubinemia, caused by the complete absence of bilirubin uridine 5'-diphosphate-glucuronosyltransferase (UGT) activity. The authors reported a 24-year-old male with this syndrome. He had severe icterus from the age of 4 days, and was diagnosed as having Crigler-Najjar syndrome type I at 51 days after birth. Despite repeated phototherapy, his serum bilirubin was increased. When bilirubin encephalopathy occurred at the age of 16 years, the serum bilirubin level was 47 mg/100 ml. EEG showed diffuse and continuous high voltage slow waves. He was treated with bilirubin adsorption, which reduced the serum bilirubin level to 10-20 mg/100 ml, with disappearance of the EEG abnormality. Subsequent liver transplantation resulted in improvement of neurological signs and symptoms, and recovery of his mental function.

In this review the historical tenets and evidence-based clinical research in support of a bilirubin exchange threshold of >20 mg/dL for the healthy term neonate are revisited. In addition, a hypothesis is ventured that recent cases of kernicterus are related in part to changes in population factors coupled with genetic predispositions that have unmasked an unappreciated potential for marked neonatal hyperbilirubinemia.

Jaundice is common in ethnic Chinese infants, but to our knowledge Crigler-Najjar syndrome (CN syndrome) type I has never been reported in China. A Chinese girl with severe jaundice was recently diagnosed to have CN syndrome type I by analyzing the bilirubin-uridinediphospho (UDP)-glucuronosyltransferase gene (UGT1A1). The patient was homozygous for a nonsense mutation that replaced glutamine (CAG, amino acid 239) with stop codon (TAG) at nucleotide number 715 (715C-->T) in exon 1. No mutation was found in exons 2-5. Her parents were heterozygous for the same mutant. The patient had an average bilirubin level of 300-500 mumol/L and a peak of 701 mumol/L. Daily phototherapy for 15 h was required to keep the bilirubin levels within 280-320 mumol/L. The unconjugated hyperbilirubinaemia apparently resulted from homozygous nonsense mutation of UGT1A1, which could completely abolish the UGT activity towards bilirubin (hepatic glucuronidation) and result in CN syndrome type I. Identification of the genetic defect is very useful for gene therapy, especially for DNA/RNA chimera therapy, and can be used as an antenatal screening test to identify the affected offsprings.

Background: Crigler-Najjar syndrome type 1 (CNS1) is characterized by severe unconjugated hyperbilirubinemia from birth, caused by total failure of UDP-glucuronyltransferase activity. Only orthotopic liver transplantation (OLT) offers the prospect of cure. However, because the onset of neurologic deficits is unpredictable, timing of OLT remains difficult., Methods: In our transplant center, 3 patients underwent early OLT for CNS1. Two of them (7 yr, 12 yr) showed mild to moderate neurologic deficits only few weeks before OLT, another patient (4 yr) had no signs of bilirubin encephalopathy. All patients required extensive phototherapy to control bilirubin levels. Thus, OLT was performed shortly after the onset of neurologic symptoms or as a prophylactic procedure, respectively., Results: OLT was uneventful in all recipients. One of the symptomatic patients (7 yr) completely recovered from neurologic deficits at 36 months on OLT, whereas the other patient (12 yr) significantly improved symptoms at 27 months of OLT. These patients, including the 4-year-old boy, attend school at appropriate grades now., Conclusions: Irreversible brain damage (kernicterus) may occur in the course of CNS1 disease. Because no alternative treatment options are available at this time, OLT should be performed as a preventive procedure to counteract severe CNS-related complications.

The genomics revolution offers novel approaches to scientific investigation. Application of genomics technologies including microarray gene chips will provide a more complete picture of biological phenomena and help define the genetic contribution to disease by monitoring changes in expression across thousands of genes in physiological and clinical contexts. We briefly summarize identified genetic components that contribute to the genesis of neonatal hyperbilirubinaemia with a focus on inborn errors of hepatic bilirubin conjugation and discuss the potential use of microarray gene expression profiling technology to enhance our understanding of the pathogenesis of hyperbilirubinaemic neuronal cell injury. Expanded study using the tools of genomics will shed insights into the genetics of newborn jaundice and the pathogenesis of hyperbilirubinaemic encephalopathy.

Background: Early and accurate diagnosis of Crigler-Najjar syndrome, which causes prolonged unconjugated hyperbilirubinaemia in infancy, is important, as orthotopic liver transplantation is the definitive treatment., Aim: To determine whether bilirubin pigment analysis of bile in infants with prolonged unconjugated hyperbilirubinaemia provides useful diagnostic information in the first 3 months of life., Methods: Retrospective review of patients with prolonged unconjugated hyperbilirubinaemia referred to the liver unit, Birmingham Children's Hospital, for the diagnosis of Crigler-Najjar syndrome. Bile bilirubin pigment composition was determined by high performance liquid chromatography. Initial diagnoses were made based on the result of bile bilirubin pigment composition. Final diagnoses were made after reviewing the clinical course, response to phenobarbitone, repeat bile bilirubin pigment composition analysis, and genetic studies., Results: Between 1992 and 1999, nine infants aged less than 3 months of age with prolonged hyperbilirubinaemia underwent bile bilirubin pigment analyses. Based on these, two children were diagnosed with Crigler-Najjar syndrome (CNS) type 1, six with CNS type 2, and one with Gilbert's syndrome. Five children whose initial diagnosis was CNS type 2 had resolution of jaundice and normalisation of serum bilirubin after discontinuing phenobarbitone, and these cases were thought to be normal or to have Gilbert's syndrome. One of the initial cases of CNS type 1 responded to phenobarbitone with an 80% reduction in serum bilirubin consistent with CNS type 2. In all, the diagnoses of six cases needed to be reviewed., Conclusions: Early bile pigment analysis, performed during the first 3 months of life, often shows high levels of unconjugated bilirubin or bilirubin monoconjugates, leading to the incorrect diagnosis of both type 1 and type 2 Crigler-Najjar syndrome.

Crigler-Najjar syndrome type I is a rare hereditary disease that is manifested by high concentration of unconjugated bilirubin in serum, which may lead to neurologic disorders. Management consists of conservative therapy and partial liver transplantation and, since recently, hepatocyte transplantation. Both therapeutic procedures have been continually improved and are yielding better results. We present a girl, aged three and a half years, who has been living at the Neonatology Department of the University Childrens Hospital in Belgrade since birth due to the permanent need for phototherapy and other measures so as to keep her bilirubin at minimal level. We present numerous management dilemmas, having in mind the controversial attitudes of physicians from other world centres, starting from those who consider that surgery should be done before the age of six years to those who consider that the patient should be treated conservatively only. Our attempts to avoid neurological disorders developing in our little patient surpasses professional interest only, because this girl is an exceptionally lovely and smart child with IQ 128.

Crigler-Najjar disease (CN) type I is characterized by persistent unconjugated hyperbilirubinemia from birth. The male patient here was diagnosed with this disease as a neonate and had been treated by phototherapy. At age 16 he suddenly developed generalized convulsions, followed by impaired cognitive function. The serum level of bilirubin was extremely high (total bilirubin: 41.7 mg/dl) and there were no other detectable causes responsible for the metabolic encephalopathy. He received bilirubin adsorption therapy several times, and the bilirubin encephalopathy improved in response to the fall in the serum level of bilirubin. After this he underwent a successful liver transplantation in Australia, and recovery of his mental faculties was satisfactory. Within the subsequent 3 years epileptic abnormal discharges on the electroencephalogram disappeared. Phototherapy alone can not prevent the rise in the serum level of bilirubin in adolescent or adult patients with CN type I, therefore such patients tend to experience life-threatening bilirubin encephalopathy. To save patients with the acute onset type of bilirubin encephalopathy, sufficient bilirubin adsorption followed by liver transplantation appears to be the most recommended therapeutic approach.

Based on the clinical course of a 16-year-old boy with type I Crigler-Najjar syndrome, we estimated the threshold concentration of unbound bilirubin, as assayed by the horseradish peroxidase method, that apparently induces toxicity to the brain. Before the age of 15, the patient did not manifest any neurological or behavioural dysfunction despite increased bilirubin in serum. The binding affinity and the binding capacity of the patient's serum albumin for bilirubin determined when he was about 14 years old were 10(8)(mol/L)-1 and 1.01 to 1.04 mol/L, respectively. These values were nearly the same as those of normal controls reported in the literature. The total bilirubin binding capacity was greater than the patient's total bilirubin concentration, showing that his serum albumin was not saturated with bilirubin. The reserve bilirubin binding capacity (RBBC) was estimated to be 158 mumol/L and the unbound bilirubin concentration to be 15.1 nmol/L. Concentration of unbound bilirubin peaked at 21.7 nmol/L at the age of 15 years and 11 months, i.e. 2 months before the onset of difficulties in walking and speaking. At this time, the RBBC was estimated as -64 mumol/L. A peak concentration of total bilirubin, 811 mumol/L, was observed during the period of rapid loss of the ability to walk or speak. At the age of 16 years and 1 month the RBBC decreased to -98 mumol/L and the unbound bilirubin concentration to 18.8 nmol/L. Following phototherapy, the patient's neurological state returned to normal; he could speak and walk normally. At the age of 16 years and 2 months the RBBC returned to 105 mumol/L and unbound bilirubin decreased to 16.6 nmol/L. These results suggest that maintaining the concentration of unbound bilirubin at < 20 nmol/L and the total bilirubin concentration at lower than the binding capacity of serum albumin is important for prevention of neurological deficits in Crigler-Najjar syndrome. The upper limit of unbound bilirubin in such an older patient was nearly the same as that reported for newborns.

Neonatal jaundice is a frequent problem in neonatology, but the advent of phototherapy which has simplified its treatment, it no longer represents a major concern. Early hospital discharge of neonates has now resulted in a re-emergence of kernicterus. Neonatal jaundice is principally the result of a transient deficiency of bilirubin conjugation, of a partial deficiency of hepatic bilirubin uptake and intracellular transport and of an increased enterohepatic circulation of the pigment. The fact that bilirubin production in the neonate is 2 or more times greater than in the adult per kilogram of bodyweight represents the mainstay of this condition. Prevention of kernicterus in full term infants is based on the detection of neonates at risk for developing hyperbilirubinaemia, and can be accomplished with simple tests performed on umbilical cord blood such as blood type, Rh, Coombs' test and glucose-6-phosphate dehydrogenase, in order to detect haemolytic diseases. The daily evaluation of transcutaneous bilirubin measurement gives additional information on the rise of serum bilirubin level, and can help to distinguish physiological from nonphysiological hyperbilirubinaemia. A significant hyperbilirubinaemia is more frequent in infants born before term, and in neonates who do not feed well and lose more than 10% of bodyweight. In preterm infants the typical clinical feature of kernicterus is seen very rarely, and kernicterus is now a very infrequent postmortem observation. Since it is very difficult to distinguish the effects of bilirubin from other potentially toxic factors, it is difficult to give guidelines for the treatment of jaundice in very low birthweight infants other than to keep the serum bilirubin levels to a lower level than in full term infant (e.g. 10 mg/dl lower than in full term babies). The intramuscular administration of a single dose of Sn-mesoporphyrin (6 mumol/kg bodyweight) in healthy term or near-term infants seems to be a promising treatment modality for controlling hyperbilirubinaemia.

Limited information exists on the neurologic sequelae of Crigler-Najjar syndrome type I despite this being the major morbidity of this rare autosomal recessive disorder of bilirubin conjugation that results in chronic unconjugated hyperbilirubinemia. Two patients with identical underlying genetic mutations resulting in Crigler-Najjar syndrome type I were assessed from a neurodevelopmental perspective in late childhood using age appropriate standardized measures. In addition, the English language literature of case reports and series describing the outcomes of patients with this disorder was reviewed (descriptive meta-analysis) and summarized with particular reference to neurologic symptomatology, pattern of neurologic disability, age of onset of symptoms, and therapeutic interventions. Despite radically different therapeutic interventions, our two patients did not differ in outcome measures. Review of the literature reveals distinct, often age-related, patterns of neurologic sequelae reflecting injury to basal ganglia, cerebellar, and likely hippocampal structures. Definitive prevention of the neurologic sequelae that often occur within the context of Crigler-Najjar syndrome type I requires that curative treatment (hepatic transplantation, presently, and gene therapy in the future) be applied prior to the possible onset of neurologic symptoms in adolescence.

We performed a questionnaire survey about 42 patients with Crigler-Najjar syndrome type 1 who were currently alive. Information was obtained on their age, sex, birth weight, gestation, parental consanguinity, other family members affected, age of onset of jaundice, neonatal and postneonatal bilirubin values, neonatal and postneonatal therapy, problems faced with phototherapy, liver transplantation, current growth status, current neurologic status, and the status of hearing. Patients were between 2 months and 21 years of age. There were 18 males and 24 females. Thirty-nine patients had been born at full term gestation and 3 had been preterm. Jaundice was noted on postnatal day 1 in 34%, between days 2 and 4 in 55%, and after day 11 of life in 11% of patients. In the neonatal period bilirubin values (mean +/- SD) were typically 19.8 +/- 4.5 mg/dL. Eighty-six percent of patients had neonatal peak bilirubin values of >20 mg/dL. Parental consanguinity was present in 44% and a history of Gilbert's disease in one parent was present in 10% of patients. Causes of exacerbations of jaundice reported were respiratory infections, febrile illnesses, vaccinations, fasting, surgery, emotional stress, and noncompliance with treatment. Neonatal therapy consisted of exchange transfusion in 28%, phototherapy in 79%, phenobarbitone in 20%, and cholestyramine, albumin, infusions, and plasmapheresis in one case each. The mainstay of postneonatal therapy was home phototherapy for 10 to 16 hours, primarily at night during sleep, using blue lights or a combination of blue and fluorescent lights. Some patients used innovatively designed phototherapy units. Problems reported with phototherapy were decreased effectiveness with age, poor compliance, restriction of activity and play, inability to travel or take vacations, irritation from eye shades, difficulty keeping eye protection on, difficulties in temperature maintenance, tanning of the skin, embarrassment from the need to be nearly nude during phototherapy, and difficulty in procuring phototherapy lamps. Other therapies that had been tried included oral agar, albumin infusions, antioxidants, acupuncture, bilirubin oxidase, calcium infusions, clofibrate, cruciferous vegetables, cholestyramine, chlorpromazine, flumecinol, plasmapheresis, tin mesoporphyrin, ursodeoxycholic acid, and urinary alkalinization. Fifteen children had undergone liver transplantation (5 auxiliary and 10 orthotopic). All 42 patients are reportedly of normal height and weight. Neurodevelopmental status is said to be normal in 77% of patients. Two patients have kernicterus, 4 have cerebellar symptoms, and 1 each has developmental delay, mild intention tremor, and mild speech delay. Hearing was reported to be normal in 94% of patients. The 2 children with hearing loss have conductive loss from otitis media. With home phototherapy prolonged, survival free of neurologic deficits is possible in Crigler-Najjar syndrome type 1, but there are many problems associated with phototherapy. Avoiding exacerbations of jaundice is an important aspect of management. Liver transplantation offers the prospect of cure but its risk versus benefit ratio is undetermined. Hearing loss was absent in the patients surveyed despite prolonged exposure to high bilirubin levels, which suggests that bilirubin may not be as ototoxic as is commonly believed.

We studied the neurophysiological features of five patients (age range: 4-20 years) suffering from Crigler-Najjar syndrome type I (CNsI) by means of multimodal (brainstem, somatosensory, motor) evoked potentials and periodic EEG-polygraphic recordings (follow-up: 3 months-4.5 years). Two patients presented with neurological disturbances, consisting mainly of mental slowing, motor impairment and seizures. Both of them presented an abnormal EEG, characterized by slowing of background activity associated with paroxysmal discharges. Liver transplantation was performed in one of these two patients and was followed by improvement of both the neurological picture and EEG activity. In a third patient, clinically normal, after two years of follow-up, the EEG started to show paroxysmal activity during sleep or when evoked by intermittent photic stimulation. In these three patients, multimodal evoked potentials were unremarkable. The remaining two younger subjects did not show any clinical or EEG abnormality. Our findings suggest that, whereas in newborns and infants evoked potentials have been demonstrated as reliable techniques to monitor bilirubin neurotoxicity, in children and adolescents with CNsI, EEG seems to be more sensitive in evaluating patients for neurological damage and effectiveness of therapeutic strategies adopted.

Characterization of the UGT1 gene complex locus encoding both multiple bilirubin and phenol UDP-glucuronosyltransferases (transferases) has been critical in identifying mutations in the bilirubin isoforms. This study utilizes this information to identify the bases of deficient bilirubin UDP-glucuronosyltransferase activity encoded by the UGT1A gene for the major bilirubin isozyme, HUG-Br1, in 3 Crigler-Najjar type I individuals and the genotype of an at-risk unborn sibling of one patient. A homozygous and heterozygous two-base mutation (CCC to CGT) created the HUG-Br1P387R mutant of the major bilirubin transferase in 2 different Crigler-Najjar type I patients, B.G. and G.D., respectively. Both parents of B.G. and his unborn sibling, J.G., were determined to be carriers of the P387R mutation. G.D. also contains the CAA to TAA nonsense mutation (G1n357st). Y.A. has a homozygous CT deletion in codons 40/41. The HUG-Br1P387R mutant protein was totally inactive at the major pH optimum (6.4), but retained 26% normal activity at the minor pH optimum (7.6), which was 5.4% of the combined activities measured at the two pH values.

Crigler-Najjar syndrome is a rare inherited deficiency of bilirubin uridine diphosphate glucuronyl transferase, characterised by lifelong unconjugated hyperbilirubinemia. We report anesthetic and postoperative management of a patient with this syndrome. A 64-yr-old man with Crigler-Najjar syndrome type II underwent cholecystectomy. Preoperative laboratory values included total bilirubin 8.4 mg.dl-1 and direct-bilirubin 1.8 mg.dl-1. He received epidural anesthesia combined with general anesthesia with nitorous oxide and isoflurane. He had no remarkable perioperative complications.

A 58-year-old Japanese man was admitted to our hospital with appendicitis and marked unconjugated hyperbilirubinemia (11.6 mg/dl). The jaundice worsened following appendectomy, and the direct-reacting bilirubin increased, probably due to the ceftizoxime administered postoperatively. Bilirubin diglucuronide was the main component of the serum direct-reacting bilirubin (51%) in serum measured by liquid chromatography. Because the discontinuation of ceftizoxime did not markedly improve the jaundice, epomediol, 200 mg tid, was administered orally. There was a marked decrease of serum bilirubin with an increase in the delta bilirubin/(conjugated bilirubin + delta bilirubin) ratio. After improvement of jaundice to below the pre-surgical level (4.4 mg/dl), we analyzed the duodenal bile for bilirubin fractions; those showed a marked reduction in bilirubin diglucuronide and a marked increase in bilirubin monoglucuronide, which was consistent with type II Crigler-Najjar syndrome. A marked increase of bilirubin diglucuronide in serum of this patient during cholestasis suggests that bilirubin conjugation proceeds in this syndrome when excretion of conjugated bilirubin decreases.

We present the case of a 23-yr-old man who had had since birth marked and sustained unconjugated non-hemolytic hyperbilirubinemia and who had had several attacks of grand mal seizures. Analysis of serum bilirubin by diazoreactive methods showed serum levels of unconjugated bilirubin as high as 445 mumol/L that were not affected by phenobarbital administration. However, analysis of serum bile pigments by high-pressure liquid chromatography demonstrated marked decrease of unconjugated bilirubin after phenobarbital treatment (from 432.4 mumol/L to 291.0 mumol/L) associated with slight increase of bilirubin monoconjugates and disconjugates (from 0.25 mumol/L to 0.42 mumol/L). Furthermore, in the past few years the patient had exhibited striking skin hyperextensibility and diaphragm eventration. This case confirms that alkaline methanolysis-high-pressure liquid chromatography is the most reliable method for assessment of serum fraction bilirubin levels; that clinical parameters such as neurological signs do not unequivocally discriminate between type I and II Crigler-Najjar disease and that response to phenobarbital treatment remains the main diagnostic tool.

We describe a 23-yr-old man with congenital unconjugated hyperbilirubinemia secondary to uridine diphosphate glucuronosyltransferase deficiency, and who cannot readily be classified as type I or type II Crigler-Najjar syndrome. After an episode of kernicterus in childhood he was treated with phenobarbital with a resultant marked decrease in his serum bilirubin concentration. Herein we describe his course after developing acute hepatitis secondary to infectious mononucleosis. He was treated acutely with plasmapheresis with prevention of any neurological sequelae despite having previously suffered from kernicterus.

A prolonged but transient neonatal jaundice due to unconjugated hyperbilirubinemia was observed in two unrelated babies who were siblings of patients with Crigler--Najjar disease (Arias type I). The bilirubin-UDP-glucuronyl transferase activity measured in the liver of both patients, at the age of 6 and 7 months, respectively, was found to be low, suggesting a permanent deficiency in bilirubin glucuronidation, which might be the expression of a heterozygote state.

The effect of phenobarbital treatment on bilirubin metabolism and bile secretion was studied in a patient with Crigler-Najjar syndrome, type II and acquired cholestasis. Following cholecystectomy and choledochostomy, a balloon inflatable T tube was inserted to facilitate bile collection. Hepatic UDP-glucuronyltransferase in surgically obtained liver tissue was 25% of normal activity and bilirubin monoconjugates accounted for greater than 80% of the pigments in bile. Phenobarbital therapy decreased the concentration of fasting serum bile acids by 33% and partially reestablished their enterohepatic cycling postprandially. The total fasting serum bilirubin concentration (greater than 90% unconjugated) increased 21% during phenobarbital treatment and was unaffected by caloric intake. Bile flow was increased 2.7 times after phenobarbital treatment. The biliary concentration of total bilirubin was increased 2.4 times, primarily due to monoconjugated bilirubin, which accounted for 91% of the biliary pigments. Bile acid, phospholipid, cholesterol, and calcium concentrations in bile were significantly increased after phenobarbital. The data indicate that even in the presence of cholestasis an underlying deficiency in bilirubin conjugation may be confirmed by biliary pigment analysis.

The plasma concentration of unconjugated bilirubin is determined by the rate at which newly synthesized bilirubin enters the plasma (bilirubin turnover) and the rate of irreversible bilirubin removal by the liver (hepatic bilirubin clearance). Measurement of each of these variables by kinetic studies with radiolabeled bilirubin permits a precise classification of cases of unconjugated hyperbilirubinemia into those due to increased bilirubin turnover (for example, hemolysis), those due to decreased bilirubin clearance (for example, Gilbert's syndrome), and those in which both mechanisms operate. The ability to quantitate hepatic bilirubin clearance makes it possible to detect gilbert's syndrome even in the presence of concomitant hemolysis. Of the hereditary disorders of bilirubin metabolism, Gilbert's syndrome is common but innocuous, whereas Crigler-Najjar syndrome is rare but devastating. An unusual case of Crigler-Najjar syndrome is described in which bilirubin encephalopathy developed at age 10. Various modalities used in an attempt to reduce her plasma bilirubin concentration by either increasing bilirubin clearance or reducing bilirubin turnover are described.