Hiperbilirrubinemias hereditarias: un diagnóstico diferencial a considerar en ictericia / Hereditary hiperbilirrubinemias: a differential diagnosis to considerer in icterus

Las hiperbilirrubinemias hereditarias (HBH) son patologías originadas por defectos en las enzimas y proteínas que participan del metabolismo de la bilirrubina. El clearence de bilirrubina incluye captación y almacenamiento en hepatocitos, conjugación, excreción hacia la bilis y recaptura de su forma conjugada por hepatocitos. Las HBH varían de acuerdo a su patogenia, presentación clínica, niveles de bilirrubinemia y tratamientos disponibles. En general son poco frecuentes, a excepción del Síndrome de Gilbert. Están las que son de predominio indirecto, como el Síndrome de Gilbert y el de Crigler-Najjar, y las de predominio directo, como el Síndrome de Dubin-Johnson y el de Rotor. En general no requieren tratamiento específico y tienen curso benigno, a excepción del Síndrome de Crigler-Najjar para el cual existen medidas terapéuticas específicas a considerar, teniendo un pronóstico reservado para algunas de sus formas de presentación. Es importante el conocimiento de estos síndromes dado el alto índice de sospecha requerido para su diagnóstico y para su diferenciación de otras patologías hepatobiliares de mayor riesgo y severidad.

Hereditary hiperbilirrubinemias (HBH) are pathologies originated from the defect of the enzymes and proteins involved in the metabolism of bilirubin. The bilirubin clearance includes uptake and storage in hepatocytes, conjugation, excretion into bile and recapture of its conjugated form by hepatocytes. HBH vary according to their pathogenesis, clinical presentation, levels of bilirubin and available treatments. Generally they are infrequent, except for Gilbert Syndrome. There are those with indirect bilirubin predominance, such as Gilbert and Crigler-Najjar syndromes, and those with direct bilirubin predominance, including Dubin-Johnson and Rotor syndromes. In general, they do not require specific treatment and have a benign course, with the exception of the Crigler-Najjar Syndrome, for which there are specific therapeutic measures to consider, as well as a reserved prognosis for some of their forms of presentation. The knowledge of these syndromes is important 2 given the high index of suspicion required for its diagnosis and for its differentiation from other hepatobiliary pathologies of greater risk and severity.

Genetic analysis of a child affected with Crigler-Najjar syndrome type II / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To detect potential mutation of the UGT1A1 gene in a child affected with Crigler-Najjar syndrome type II.</p><p><b>METHODS</b>Blood samples were collected from the patient and his parents for the extraction of genomic DNA. Potential mutation of the UGT1A1 gene was detected with polymerase chain reaction (PCR) and direct sequencing. The child was followed up until the age of 3 years and 6 months.</p><p><b>RESULTS</b>The patient showed persistent unconjugated hyperbilirubinemia. Sequencing of the UGT1A1 gene has detected a rare heterozygous c.610 A>G (p.Met204Val) mutation in the exon 1, in addition with a heterozygous c.1091 C>T (p.Pro364Leu) mutation in exon 4. The two mutations were inherited from his father and mother, respectively. The patient was diagnosed with Crigler-Najjar syndrome type II and received oral phenobarbital treatment.</p><p><b>CONCLUSION</b>The compound UGT1A1 gene mutation probably accounts for the disease in the patient manifesting persistent mild unconjugated hyperbilirubinemia. Genetic counseling and prenatal diagnosis should be provided for his family.</p>

Evolución prolongada en síndrome de Crigler-Najjar tipo I / Crigler-Najjar syndrome. Report of one case with a long term follow up

Crigler-Najjar Syndrome is an uncommon genetic disorder characterized by the elevation of unconjugated plasmatic bilirubin secondary to deficiency of the enzyme uridine diphosphate glucuronyltransferase (UDP-GT). We report a 19-years-old woman with the syndrome diagnosed during the neonatal period, when she developed a severe jaundice in the first 10 days of life, reaching unconjugated bilirubin levels of 29 mg/dl, with normal liver function tests. After transient response to phototherapy, the patient was referred to a tertiary medical center in which an extensive work up ruled out other etiologies and the diagnosis of type I Crigler-Najjar syndrome was established. Currently, the patient has a mild mental retardation. She is receiving homemade phototherapy 18 h per day with acceptable control of bilirubin levels. Many mutations have been associated with UDP-GT dysfunction resulting in a broad spectrum of the disease. When bilirubin rises above physiological limits, it permeates the hematoencephalic barrier, inducing bilirubin impregnation of basal ganglia with secondary neuronal damage and necrosis. The worst outcome, kernicterus, is characterized by mental retardation, central deafness, ophthalmoplegia, ataxia, athetosis, spasticity, seizures and death. First line therapy includes phototherapy, but definitive therapy is liver transplantation before the occurrence of neurological damage.

Molecular Analysis of the UGT1A1 Gene in Korean Patients with Crigler-Najjar Syndrome Type II / 대한소아소화기영양학회지

PURPOSE: Crigler-Najjar syndrome type II (CN-2) is characterized by moderate non-hemolytic unconjugated hyperbilirubinemia as a result of severe deficiency of bilirubin uridine diphosphate-glucuronosyltransferase (UGT1A1). The study investigated the mutation spectrum of UGT1A1 gene in Korean children with CN-2. METHODS: Five Korean CN-2 patients from five unrelated families and 50 healthy controls were enrolled. All five exons and flanking introns of the UGT1A1 gene were amplified by polymerase chain reaction (PCR) and the PCR products were directly sequenced. RESULTS: All children initially presented with neonatal jaundice and had persistent indirect hyperbilirubinemia. Homozygous p.Y486D was identified in all five patients. Three patients had an associated homozygous p.G71R and two a heterozygous p.G71R. The allele frequency of p.Y486D and p.G71R in healthy controls was 0 and 0.16, respectively. No significant difference in mean serum bilirubin levels was found between homozygous carriers of p.G71R and heterozygous carriers. CONCLUSION: The combination of homozygous p.Y486D and homozygous or heterozygous p.G71R is identified. The p.Y486D and p.G71R can be screened for the mutation analysis of UGT1A1 in Korean CN-2 patients.

Crigler-Najjar syndrome type 2: Novel UGT1A1 mutation.

Crigler-Najjar syndrome type 2 is a rare cause for persistent unconjugated hyperbilirubinemia, inherited in an autosomal recessive manner. Even though it is compatible with normal life span, in the absence of prompt suspicion and intensive management it can prove fatal not only in the neonatal period but also during adult life. Here, we describe a case with a novel homozygous UGT1A1 p.Pro176Leu mutation.

Hereditary Spherocytosis Coexisting with UDP-Glucuronosyltransferase Deficiency Highly Suggestive of Crigler-Najjar Syndrome Type II

Patients with co-existing hereditary spherocytosis (HS) and UDP-glucuronosyltransferase 1A1 (UGT1A1) deficiency as Gilbert's syndrome (GS) have been reported, and previous studies have demonstrated an increased risk for developing gallstones in patients with co-inheritance of GS and HS. We experienced an interesting case of HS showing persistent jaundice after splenectomy, and upon further evaluation, the 25-year-old female patient was found to have HS combined with UGT1A1 deficiency. Sequence analysis of the UGT1A1 gene revealed that she was a compound heterozygote with p.[G71R; Y486D] + [Y486D] mutations, which suggests Crigler-Najjar syndrome type II rather than GS. Careful evaluation of inappropriately elevated bilirubin level compared with the degree of hemolysis is important, reflecting the therapeutic implication of splenectomy and cholecystectomy.

A new frame-shifting mutation of UGT1A1 gene causes type I Crigler-Najjar syndrome / 中华医学杂志(英文版)

We present a case of severe persisting unconjugated hyperbilirubinemia in a Uigur infant boy, eventually diagnosed as Crigler-Najjar syndrome type I. DNA analysis of his blood of the UGT1A1 gene sequence demonstrated that he was homozygous for an insertion mutation causing a change of the coding exons with a frame-shift, resulting in the substitution of 27 abnormal amino acid residues in his hepatic bilirubin uridine diphosphoglucuronyl transferase enzyme. Both of his parents were heterozygous for the same mutation. A novel frame-shifting mutation of the UGT1A1 gene was found, confirming the diagnosis of Crigler-Najjar syndrome type I for this patient.

Hiperbilirrubinemia indirecta de origen genético: informe de un caso de síndrome de Crigler-Najjar de tipo II / Indirect hyperbilirubinemia of genetic origin: case report of Crigler-Najjar syndrome type II

El síndrome de Crigler Najjar II aparece por un déficit en la conjugación de la bilirrubina debido a la deficiencia parcial de la enzima uridindifosfato-glucuronil transferasa. Por lo general, tiene un curso benigno, a diferencia del Crigler Najjar de tipo I, donde el déficit enzimático es total y los afectados mueren a edades tempranas. Se presenta el caso de una adolescente de16 años con hiperbilirrubinemia indirecta, síndrome convulsivante y parálisis cerebral. Una correcta historia clínica con estudio genealógico y pruebas funcionales apropiadas, permitieron determinar el diagnóstico definitivo. Esta enfermedad genética se transmite de forma autosómica recesiva, tiene una prevalencia muy baja a nivel mundial y constituye, en general, un reto diagnóstico para los médico.

Crigler Najjar syndrome type II is related to a defect of bilirubin conjugation due to partial deficiency of the enzyme uridine diphosphate-glucuronyl transferase. Usually has a benign course, unlike Crigler Najjar type I, where the enzyme deficiencyis total and the affected patients usually die at early ages. We present the case of a teenager with indirect hyperbilirubinemia, seizures and cerebral palsy. A good clinical historywith pedigree and appropriate functional tests allowed us to determine the definitive diagnosis. This is an autosomal recessive disorder, has a very low prevalence worldwide, and is adiagnostic challenge for physicians in general.

A Case of Crigler-Najjar Syndrome Type 2 Diagnosed Using Genetic Mutation Analysis / 대한소아소화기영양학회지

Crigler-Najjar syndrome is a rare inherited disease associated with unconjugated hyperbilirubinemia. It is inherited via an autosomal recessive pattern and is caused by mutation in one of the five exons of the bilirubin uridine-diphosphoglucuronate glucuronosyltransferase (UGT1A1) gene. The synthesis of inactive isoforms of bilirubin uridine-diphosphoglucuronate glucuronosyltransferase (B-UGT) results in unconjugated hyperbilirubinemia. A 13-year-old boy with jaundice for 4 months was admitted to our hospital. He had unconjugated hyperbilirubinemia with no evidence of infection, hemolysis, or structural abnormalities on abdominal ultrasonography or 99mTc-DISIDA scan. The authors identified a missense mutation of Tyr486Asp in the fifth exon of the UGT1A1 gene and diagnosed the patient with Crigler-Najjar syndrome type II. This is the first reported case of Crigler-Najjar syndrome in a Korean child, and it is also the first reported case of a genetic mutation leading to Crigler-Najjar syndrome in Korea.

A Case of Crigler-Najjar Syndrome Type 2 Diagnosed Using Genetic Mutation Analysis / 대한소아소화기영양학회지

Crigler-Najjar syndrome is a rare inherited disease associated with unconjugated hyperbilirubinemia. It is inherited via an autosomal recessive pattern and is caused by mutation in one of the five exons of the bilirubin uridine-diphosphoglucuronate glucuronosyltransferase (UGT1A1) gene. The synthesis of inactive isoforms of bilirubin uridine-diphosphoglucuronate glucuronosyltransferase (B-UGT) results in unconjugated hyperbilirubinemia. A 13-year-old boy with jaundice for 4 months was admitted to our hospital. He had unconjugated hyperbilirubinemia with no evidence of infection, hemolysis, or structural abnormalities on abdominal ultrasonography or 99mTc-DISIDA scan. The authors identified a missense mutation of Tyr486Asp in the fifth exon of the UGT1A1 gene and diagnosed the patient with Crigler-Najjar syndrome type II. This is the first reported case of Crigler-Najjar syndrome in a Korean child, and it is also the first reported case of a genetic mutation leading to Crigler-Najjar syndrome in Korea.

Sindrome de crigler-najjar: variabilidad clínica / Crigler-najjar syndrome: clinical variability

El síndrome de Crigler Najjar (SCN), de Herencia autosómica recesiva, es un trastorno causado por una deficiencia de la enzima bilirrubin UDP glucuronil transferasa. Se describen dos tipos de acuerdo a la ausencia o reducción de la actividad enzimática. Los pacientes presentan ictericia con aumento de bilirrubina inderecta desde el nacimiento y riesgo de Kernnícterus. El tratamiento consiste en exsanguino transfuciones (EXT) durante el período neonatal y lumino terapia (LMT) diaria prolongada. El transplante hepático es la única opción terapéutica curativa para el tipo 1. El tipo 2 responde al fenobarbital. El objetivo de este trabajo fue analizar retrospectivamente dos pacientes con SCN. En ambas se descartaron otras causas de hiperbilirrubinemia inderecta. Caso Clínico 1: Sexo femenino, eutrófica, comenzó con ictericia a los 3 días de vida, 72 horas más tarde la bilirrubina total (BT) era de 24mg/dl a predominio indirecto (BI), recibió LMT hasta los 25 días de vida, luego fenobarbital y LMT domiciliaria, 8 horas/día, con buena respuesta. A los 8 meses, con una BI 5.5 mg/dl se suspendió la LMT. Los valores de BI posteriores oscilaron entre 6 8 mg/dl, bajo tratamiento con FB. Debido a su evolucion clínica, se planteó como diagnóstico SCN tipo 2. Caso Clínico 2: Sexo femenino, eutrófica, presentó ictericia desde los 12 días de vida, con niveles de BI de 39mg/dl, se realizaron EXT y LMT. El examen neurológico era normal. Se indicó LMT domiciliaria 12 16 Hs/d y FB. La paciente persistió con valores de BI>20mg/dl. Se asumió como probable SCN tipo 1. Se inició evaluación pre trasplante hepático.Palabras clave: síndrome de Crigler Najjar, dianóstico, tratamiento, evolución

Transplante hepático en una paciente con daño neurológico ¿un recurso terapéutico excepcional?: algunas reflexiones bioéticas / Liver transplantation in a patient with neurological damage: a one-off treatment?: some bioethical considerations

Se presenta el dilema ético-clínico planteado por el caso de una paciente de 8 años 6 meses de edad, portadora de enfermedad hepática con daño neurológico irreversible y severo en la cual los padres solicitan la posibilidad de realizar un transplante hepático. Se trata de la única hija de padres sanos, preocupados y responsables del manejo de su hija, con un riesgo de recurrencia de esta enfermedad de 25 porciento para otro hijo. Se discuten las posibilidades de hacer todo lo terapéuticamente posible o si se debe tomar la decisión de limitar los tratamientos. Con el objetivo de mostrar un proceso de deliberación bioética y de permitir al lector confrontar sus apreciaciones personales, se presenta el caso clínico, seguido de dos comentarios independientes

Ictericia neonatal I. fisiopatología, etiología, diagnóstico y encefalopatía bilirrubínica / Neonatal jaindice I. phisiology, etiology, diagnosis, and bilirubin encephalopathy

La ictericia neonatal es uno de los principales problemas a que se enfrentan los pediatras y neonatólogos en la consulta externa y en las áreas de urgencias y hospitalización. Decidir cuándo esta ictericia es fisiológica y cuándo requiere un abordaje completo a fin de determinar el origen y establecer el tratamiento adecuado, es uno de los retos más grandes en los últimos años debido a la falta de consenso entre los diferentes grupos de especialistas. En esta revisión se presentan aspectos de fisiopatología para entender mejor los mecanismos de producción de hiperbilirrubinemia indirecta en el neonato, se analizan las principales causas de ésta y se hace hincapié en los problemas hemolíticos y los conceptos actuales con relación a la ictericia por leche materna. Asimismo se presentan algunas entidades no tan comunes pero que deben considerarse en el diagnóstico diferencial de estos pacientes. Se presentan de manera modificada las recomendaciones de 1994 de la Academia Americana de Pediatría para el abordaje diagnóstico de estos niños al tomar en cuenta las características particulares de nuestra población y también se analizan los mecanismos implicados en la encefalopatía bilirrubínica, el cuadro clínico y algunas controversias relacionadas con el neurodesarrollo de estos niños.

Metabolismo de la bilirrubina: II. Alteraciones primarias del metabolismo de la bilirrubina / Bilirrubin metabolism: II. Primary changes of the bilirubin metabolism

Las alteraciones estructurales o funcionales que afectan a los sistemas hepático, biliar o hematológico pueden producir acumulación de bilirrubina en los tejidos lo que clínicamente se traduce como ictericia. Las ictericias pueden clasificarse de acuerdo a la cantidad y tipo de bilirrubina sérica predominantemente detectada en hiperbilirrubinemias conjugadas y no conjugada. La hiperbilirrubinemia no conjugada en los niños habitualmente se observa en procesos autolimitados o "benignos" mientras que la hiperbilirrubinemia conjugada traduce siempre un daño hepático serio. Existen diversas condiciones en las cuales el metabolismo anormal de la bilirrubina conduce a enfermedad en el hombre. Los trastornos del metabolismo de la bilirrubina ocurren a diferentes niveles y la expresión clínica de ellas es por lo tanto variable. Los cuadros clínicos pueden dividirse en hiperbilirrubinemia noconjugada hereditaria, hiperbilirrubinemia conjugada hereditaria y en hiperbilirrubinemia no conjugada no hereditaria. En la presente revisión se analizaran únicamente los trastornos primários del metabolismo de la bilirrubina; los trastornos en los cuales se eleva fundamentalmente la bilirrubina conjugada en forma secundaria están más allá de los objetivos de la presente revisión