Outcome and toxicities associated to chemotherapy in children with acute lymphoblastic leukemia and Gilbert syndrome. Usefulness of UGT1A1 mutational screening.

BACKGROUND: Acute lymphoblastic leukemia (ALL) is the most frequent cancer in childhood. Although intensive chemotherapy has improved survival in those patients, important side effects, including hyperbilirubinemia, are frequent. Gilbert syndrome (GS) is a frequent condition that causes a reduction in glucuronidation and intermittent hyperbilirubinemia episodes. This could provoke a greater exposure to some cytotoxic agents used in ALL, increasing the risk of toxicity. On the other hand, unexplained hyperbilirubinemia could lead to unnecessary modifications or even treatment withdrawals, which could increase the risk of relapse, but data regarding this in ALL pediatric population are scarce. METHODS: Retrospective study to analyze toxicity, outcome and treatment modifications related to GS in children diagnosed with ALL. RESULTS: A total of 23 of 159 patients were diagnosed with GS. They had statistically higher hyperbilirubinemias during all treatment phases (P < 0.0001) and a slower methotrexate clearance when it was administered during a 24-hr infusion at high doses (patients with GS: 74 hr ± 19 vs. patients without GS: 64 hr ± 8; P < .002). However, no relevant toxicity or delays in treatment were found in them. Finally, changes in treatment due to hyperbilirubinemia were only done in 5 patients with GS. CONCLUSIONS: Differences in outcome were not found in patients with GS. Universal screening for GS appears to be not necessary in pediatric patients with ALL. However, when hyperbilirubinemia is observed, it must be rule out in order to avoid unnecessary changes in treatment.

[Hirschsprung's disease and medullary carcinoma of the thyroids: two diseases in a monogenetic disorder]. / La enfermedad de Hirschsprung y el carcinoma medular de tiroides: dos enfermedades en una alteración monogénica.

INTRODUCTION: The most common gene involved in Hirschsprung's disease (HD) is protooncogene RET. More than 100 mutations of this gene have been described associated with HD. The mutations that change a cysteine with another aminoacid (mainly in exons 10 and 11) give a risk of familial medullary thyroid carcinoma (FTMC) and MEN 2A. These mutations are found in 5% of patients with HD and have an autosomal dominant inheritance. The FTMC is aggressive and the prophylactic thyroidectomy is the best treatment. We present our results in screening for RET protooncogene mutations associated with TMC in patients with HD. PATIENTS AND METHODS: We have treated 40 patients with HD in the last 15 years. We have classified the patients into two groups: A) high risk of RET protooncogene mutation associated with FTMC (family history of HD, long-segment and/or associated syndromes) and B) low risk (rectosigmoid involvement). We have identified the exons 7, 8, 9, 10, 11, 13, 14 and 15 of the RET protooncogene in 12 of 15 children from group A and 6 from 25 from group B. RESULTS: We have found the p.Cys620Ser mutation (exon 10) in a girl from group A (long-segment). In the family study, we have found the same mutation in her mother, her oncle and her cousin. CONCLUSION: The comprehensive management of children with HD requires screening for RET protooncogene mutations associated with FTMC. In the first-degree relatives of children with a mutation risk, screening is required.

La enfermedad de Hirschsprung y el carcinoma medular de tiroides: dos enfermedades en una alteración monogénica / Hirschsprung’s disease and medullary carcinoma of the thyroids: Two diseases in a monogenetic disorder

Introducción. Las mutaciones del protooncogén RET son las más frecuentes en la enfermedad de Hirschsprung (EH). Hay descritas más de 100 mutaciones de este gen asociadas a EH, pero aquellas en que el error reemplaza una cisteína por otro aminoácido (principalmente en exones 10 y 11) presentan riesgo de MEN 2A y carcinoma medular de tiroides familiar (CMTF). Estas mutaciones de riesgo se hallan en un 5% de los pacientes con EH y presentan una herencia autosómica dominante. El CMTF tiene un comportamiento agresivo y la tiroidectomía profiláctica es el mejor tratamiento. Presentamos nuestros resultados en el cribado de las mutaciones del gen RET asociado a CMT en pacientes afectos de EH. Pacientes y método. Se han tratado en nuestro hospital 40 pacientes con EH en los últimos 15 años. Hemos clasificado a los pacientes en dos grupos: A) alto riesgo de mutación del gen RET asociada a CMTF (antecedentes familiares de EH, segmento largo y/o síndromes asociados) y B) bajo riesgo (afectación rectosigmo idea exclusiva).Se han determinado los exones 7, 8, 9, 10, 11, 13, 14 y 15 del protooncogén RET en 12/15 niños del grupo A y en 6/25 del grupo B. Resultados. Una niña del grupo A presenta la mutación p.Cys620Ser (exón 10). En el estudio familiar se ha encontrado esta misma mutación en la madre, el tío materno y una de sus hijas. Conclusiones. El manejo integral de los niños con EH exige el despistaje de mutaciones del gen RET asociadas a CMTF. En los familiares de primer grado de los niños con una mutación de riesgo, el cribado es obligatorio (AU)

Introduction. The most common gene involved in Hirschsprung’s disease (HD) is protooncogene RET. More than 100 mutations of this gene have been described associated with HD. The mutations that change a cysteine with another aminoacid (mainly in exons 10 and 11) give a risk of familial medullary thyroid carcinoma (FTMC) and MEN 2A. These mutations are found in 5% of patients with HD and have an autosomal dominant inheritance. The FTMC is aggressive and the prophylactic thyroidectomy is the best treatment. We present our results in screening for RET protooncogene mutations associated with TMC in patients with HD. Patients and methods. We have treated 40 patients with HD in the last 15 years. We have classifi ed the patients into two groups: A) high risk of RET protooncogene mutation associated with FTMC (family history of HD, long-segment and/or associated syndromes) and B) low risk (rectosigmoid involvement).We have identified the exons 7, 8, 9, 10, 11, 13, 14 and 15 of the RET protooncogene in 12 of 15 children from group A and 6 from 25 from group B. Results. We have found the p.Cys620Ser mutation (exon 10) in a girl from group A (long-segment). In the family study, we have found the same mutation in her mother, her oncle and her cousin. Conclusion. The comprehensive management of children with HD requires screening for RET protooncogene mutations associated with FTMC. In the fi rst-degree relatives of children with a mutation risk, screening is required (AU)

[Griscelli-Prunieras syndrome: report of two cases]. / Síndrome de Griscelli-Prunieras: a propósito de dos casos.

Griscelli-Prunieras syndrome (GS) is a rare autosomal recessive disorder characterized by partial albinism. His pathogenic mechanism is associated with defects in the packaging of melanin and other cellular proteins. GS is classified into 3 types based on the genetic and molecular features. Mutations in the genes which cause GS are known. We report two first cases described in Spain who presented a silver-gray sheen of the hair and a severe immune disorder. They were studied for mutations principally related to this syndrome. Two patients showed the Rab27a mutation (frequently associated with GS2). The natural disorder evolution differs considerably among the various forms, so a genetic study is essential in GS to achieve the most accurate prognosis and treatment possible.

Síndrome de Griscelli-Prunieras: a propósito de dos casos / Griscelli-Prunieras syndrome: report of two cases

El síndrome de Griscelli-Prunieras (SGP) es una rara entidad de herencia autonómica recesiva que se presenta con albinismo parcial. Su patogenia se explica por alteraciones en los genes que regulan el transporte de melanosomas. Se han descrito tres tipos en base a sus características genéticas y moleculares. Se conocen las mutaciones relacionadas con este síndrome. A continuación presentamos dos pacientes, no descritos anteriormente en España, que presentaban un cabello gris-plateado característico e inmunodeficiencia cuyo estudio genético demostró la mutación en el gen Rab27A (asociado al SG2). El pronóstico y tratamiento difiere considerablemente entre las diferentes formas de la enfermedad, por lo que el diagnóstico genético precoz es fundamental para poder establecer un pronóstico y tratamiento adecuados (AU)

Griscelli-Prunieras syndrome (GS) is a rare autosomal recessive disorder characterized by partial albinism. His pathogenic mechanism is associated with defects in the packaging of melanin and other cellular proteins. GS is classified into 3 types based on the genetic and molecular features. Mutations in the genes which cause GS are known. We report two first cases described in Spain who presented a silver-gray sheen of the hair and a severe immune disorder. They were studied for mutations principally related to this syndrome. Two patients showed the Rab27a mutation (frequently associated with GS2). The natural disorder evolution differs considerably among the various forms, so a genetic study is essential in GS to achieve the most accurate prognosis and treatment possible(AU)