Pregnancy outcome in maternal Crigler-Najjar syndrome type II: a case report and systematic review of the literature

A Case of Crigler-Najjar Syndrome Type II During Pregnancy and Its Management

Crigler-Najjar syndrome (CNS) is a genetic syndrome that results in increased levels of unconjugated bilirubin due to less or completely nonfunctional enzyme, uridine diphosphoglucoronyltransferase (UDPGT) in hepatocytes. When bilirubin metabolism is compromised, hyperbilirubinemia is caused, which results in increased levels of unconjugated and conjugated bilirubin in the bloodstream. CNS is an autosomal recessive disorder, usually noticeable as people get older. This disorder is divided into two types: CNS type I and CNS type II, which are caused by homozygous or compound heterozygous mutations in the UDP glucuronosyltransferase family 1 member A1 (UGT1A1) gene. The disorder affects all races and genders equally, with a prevalence of one per million births. CNS type I is more severe and has almost undetectable UDPGT expression activity, and affected individuals die before one year of age. Consanguineous marriages are a major risk factor as CNS is inherited in an autosomal recessive manner. Being rare, maternal CNS type II is yet to be completely understood in terms of its impact on the mother, her pregnancy, and the infant. We aim to present a case of a pregnant female with CNS type II and its clinical course. She was monitored closely during her pregnancy. The treatment protocol was followed as per previously reported cases and was managed on low, non-teratogenic doses of phenobarbitone. A successful outcome with the birth of a healthy infant having normal neurological development till six months follow-up was observed.

Crigler-Najjar type II in pregnancy: A case report

Crigler-Najjar is a rare, autosomal recessive disorder that results in mutations causing a complete absence (type I) or deficiency (type II) of the hepatic uridine diphospho-glucuronosyl transferase (UDPGT) enzyme. Both forms, however, result in unconjugated hyperbilirubinaemia which can lead to kernicterus and potentially death. Phenobarbitone can be used as an enzyme inducer in Type II to facilitate a reduction in total serum bilirubin. We report two consecutive pregnancies in a 29-year-old woman with Crigler-Najjar Type II syndrome. Phenobarbitone therapy was commenced in the first pregnancy at 16 weeks' gestation and was associated with favorable biochemical and clinical outcomes. There were no reports of long-term neonatal neurological sequelae. Tertiary center, multidisciplinary care is recommended for optimal pregnancy outcomes.

Case report: multiple UGT1A1 gene variants in a patient with Crigler-Najjar syndrome

BACKGROUND

Inherited unconjugated hyperbilirubinemia is caused by variants in the gene UGT1A1 leading to Gilbert's syndrome and Crigler-Najjar syndrome types I and II. These syndromes are differentiated on the basis of UGT1A1 residual enzymatic activity and its affected bilirubin levels and responsiveness to phenobarbital treatment.

CASE PRESENTATION

In this report, we present a boy with Crigler-Najjar syndrome type II with high unconjugated bilirubin levels that decreased after phenobarbital treatment but increased in adolescence. Four different UGT1A1 gene variants have been identified for this patient, of which one is novel (g.11895_11898del) most likely confirming diagnose molecularly.

CONCLUSIONS

The presented case highlights the challenges encountered with the interpretation of molecular data upon identification of multiple variants in one gene that are causing different degree reducing effect on enzyme activity leading to several clinical conditions.

Liver Fibrosis Associated With Crigler-Najjar Syndrome in a Compound Heterozygote: A Case Report

Crigler-Najjar syndrome is a hereditary unconjugated hyperbilirubinemia. Two forms of the disease are recognized. Type I is more severe and results in kernicterus if left untreated, and Type II is less severe and responds to phenobarbital. While Crigler-Najjar syndrome is thought by many to have normal liver histology, few reports of the liver pathology exist. Herein, we present a 19-year-old patient with Crigler-Najjar who underwent liver transplantation. The liver showed marked canalicular cholestasis with portal and variable, delicate, bridging fibrosis. Correlation of the patient's genetic test results and clinical phenotype is presented.

Crigler Najjar Syndrome Type 2 (CNS Type 2): An Unwonted Cause of Jaundice in Adults

Crigler Najjar Syndrome (CNS) Type 2 is an uncommon genetic disorder characterised by non-haemolytic unconjugated hyperbilirubinemia. It is caused by mutations in the UGT1A1 gene which codes for the enzyme uridine diphosphate glucoronosyl transferase- 1, required for the conjugation and further excretion of bilirubin from the body. Affected individuals are usually asymptomatic apart from the jaundice and investigations reveal isolated indirect hyperbilirubinemia. It can be conveniently diagnosed by evaluating the response to phenobarbitone in terms of fall in bilirubin levels. Genetic testing of the UGT1A1 gene for mutations is the diagnostic clincher. However, case reports documenting the genetic mutational analysis are sparse. We report one such rare case.

Etiology, clinical profile, and outcome of liver disease in pregnancy with predictors of maternal mortality: A prospective study from Western India

BACKGROUND

The aim of this study is to study the etiology, clinical profile, and prognostic factors related to maternal and fetal health in pregnant patients with liver disease in Western India.

METHODS

This study included 103 consecutive pregnant patients with liver dysfunction from August 2013 to July 2015, who underwent regular biochemical tests, viral markers, ultrasound of abdomen, etc. and were followed up for 6 weeks postpartum or until death.

RESULTS

Pregnancy-specific causes of liver dysfunction were found in 39 % (40/103) patients. Liver diseases were most frequent in third trimester 69.9 % (72/103). Etiologies in third trimester were viral hepatitis 36.1 % (26/72), pregnancy induced hypertension (PIH) 30.5 % (22/72), intrahepatic cholestasis of pregnancy 11.1 % (8/72), acute fatty liver of pregnancy (2/72), etc. Hepatitis E was the commonest agent among viral hepatitis 71.8 % (28/39). Causes of maternal mortality (n = 25) were hepatitis E 40 % (10/25), PIH 32 % (8/25), and tropical diseases 20 % (5/25). Fetal mortality (n = 31) was 38.7 % (12/31) in hepatitis E. Maternal mortality was significantly associated with presence of jaundice, fever, abdominal pain, oliguria, anemia, leukocytosis, and coagulopathy. Model for end-stage liver disease (MELD) score >21 predicted maternal mortality with 80 % sensitivity and 91 % specificity (area under the receiver operating characteristic curve = 0.878 and p < 0.001).

CONCLUSIONS

Liver disease was most common in the third trimester of pregnancy. Hepatitis E was the most common cause of liver disease in pregnant women in western India with significant maternal mortality, predicted by high MELD score.

Management of pregnancy in Crigler Najjar syndrome type 2

Crigler Najjar syndrome is associated with indirect hyperbilirubinemia due to a deficiency of enzyme Uridine Di Phospho Glucoronosyl Transferase (UDPGT). Presented here is a case of a female in the first trimester of pregnancy, who was diagnosed to have type 2 Crigler Najjar syndrome. We also discuss the management of this rare disease especially in pregnancy. Unconjugated bilirubin can cross the placental barrier causing neurological damage in the newborn. Patient was carefully monitored during pregnancy and treatment with phenobarbitone in low doses was adjusted such that the serum bilirubin levels were below 10 mg/dL. Crigler Najjar syndrome being rare needs to be diagnosed early in pregnancy to avoid adverse fetal outcomes. Phenobarbitone being an inducer of enzyme UDPGT is used as the first line of treatment and is not teratogenic in the low doses used. Treatment protocol followed was on the basis of previous reported cases and successful perinatal outcome was achieved.

Gilbert and Crigler Najjar syndromes: an update of the UDP-glucuronosyltransferase 1A1 (UGT1A1) gene mutation database

UGT1A1 enzyme defects are responsible of both Gilbert syndrome (GS) and Crigler-Najjar syndrome (CNS). GS depends on a variant TATAA element (which contains two extra TA nucleotides as compared to the wild type genotype) in the UGT1A1 gene promoter resulting in a reduced gene expression. On the contrary, CNS forms are classified in two types depending on serum total bilirubin concentrations (STBC): the more severe (CNS-I) is characterized by high levels of STBC (342-684μmol/L), due to total deficiency of the UGT1A1 enzyme, while the milder one, namely CNS-II, is characterized by partial UGT1A1 deficiency with STBC ranging from 103 to 342μmol/L. GS and CNS are caused by genetic lesions involving a complex locus encoding the UGT1A1 gene. The present report provides an update of all reported UGT1A1 gene mutations associated to GS and CNS.

Recommendations for pregnancies in patients with crigler-najjar syndrome

During pregnancy, the developing foetus in mothers with Crigler-Najjar type 1 and 2 is exposed to raised levels of unconjugated bilirubin, with the risk of neurotoxicity. We describe two pregnancies in a patient with Crigler-Najjar type 2, who was carefully monitored prior to and during pregnancy and phototherapy adjusted to maintain serum bilirubin levels below 200 μmol/l and the bilirubin/albumin molar ratio below 50%. Both pregnancies resulted in normal delivery of healthy infants who had normal neurological development. A review of all reported pregnancies in Crigler-Najjar patients and a set of recommendations are presented.

Hereditary hyperbilirubinemia and its molecular diagnosis

Hereditary hyperbilirubinemia is caused by genetic defects in the enzymes that control bilirubin metabolism. It includes Gilbert syndrome (GS), Crigler-Najjar syndrome (CNS), Lucey-Driscoll syndrome (LDS), Dubin-Johnson syndrome (DJS), Rotor syndrome (RS) and progressive familial intrahepatic cholestasis (PFIC). This literature review covers the molecular basis of and laboratory detection methods for hereditary hyperbilirubinemia.