Nuevas mutaciones asociadas a la enfermedad de Hirschsprung / New mutations associated with Hirschsprung disease

INTRODUCCIÓN: La enfermedad de Hirschsprung está causada por un defecto de la migración celular desde la cresta neural hasta el tracto gastrointestinal, resultando en la ausencia de neuronas en el plexo mientérico. Mutaciones en varios genes han sido asociadas a la enfermedad de Hirschsprung, la mayoría afectando a la vía del protooncogén RET. El objetivo de este estudio es la descripción de mutaciones tanto descritas como nuevas asociadas a la enfermedad de Hirschsprung, así como sus implicaciones pronósticas. MATERIAL Y MÉTODOS: Análisis retrospectivo de pacientes con enfermedad de Hirschsprung y resultados genéticos positivos desde 1970 hasta 2013. RESULTADOS: En la serie global, 21 pacientes tenían resultados genéticos positivos, 17 de ellos afectando la vía del protooncogén RET. Dos de las mutaciones son nuevas y no han sido previamente descritas en la literatura médica. CONCLUSIONES: El protooncogén RET es el principal gen asociado a la enfermedad de Hirschsprung. Todavía hay múltiples mutaciones desconocidas relacionadas con la patogenia de la enfermedad. El estudio genético del gen RET debe formar parte del estudio diagnóstico de todos los pacientes con enfermedad de Hirschsprung, así como de sus familiares de primer grado en caso de que las mutaciones estén asociadas a los síndromes MEN2A y MEN2B

INTRODUCTION: Hirschsprung disease is caused by an impairment in cell migration from the neural crest to the gastrointestinal tract, resulting in an absence of neurons in the myenteric plexus. Many mutations in several genes have been associated to Hirschsprung disease; most of them affecting the RET proto-oncogen pathway. The purpose of this study is the description of novel and known mutations in genes associated to Hirschsprung disease and their prognostic implications. MATERIAL AND METHODS: Retrospective analysis of patients with Hirschsprung disease and positive genetic studies evaluated from 1970 to 2013. RESULTS: We found 21 positive genetic studies in the global series, 17 of them involving the RET proto-oncogene. Two of the mutations are novel and they have not been reported in the medical literature. CONCLUSIONS: The RET protooncogene is the main gene associated with Hirschsprung disease. There are still multiple unknown mutations related to the pathogenesis of the disease. The study of this gene must be part of the work-up of all patients with Hirschsprung disease, as well as their first degree relatives if the mutation is associated with MEN2A and MEN2B syndromes

[New mutations associated with Hirschsprung disease]. / Nuevas mutaciones asociadas a la enfermedad de Hirschsprung.

INTRODUCTION: Hirschsprung disease is caused by an impairment in cell migration from the neural crest to the gastrointestinal tract, resulting in an absence of neurons in the myenteric plexus. Many mutations in several genes have been associated to Hirschsprung disease; most of them affecting the RET proto-oncogen pathway. The purpose of this study is the description of novel and known mutations in genes associated to Hirschsprung disease and their prognostic implications. MATERIAL AND METHODS: Retrospective analysis of patients with Hirschsprung disease and positive genetic studies evaluated from 1970 to 2013. RESULTS: We found 21 positive genetic studies in the global series, 17 of them involving the RET proto-oncogene. Two of the mutations are novel and they have not been reported in the medical literature. CONCLUSIONS: The RET protooncogene is the main gene associated with Hirschsprung disease. There are still multiple unknown mutations related to the pathogenesis of the disease. The study of this gene must be part of the work-up of all patients with Hirschsprung disease, as well as their first degree relatives if the mutation is associated with MEN2A and MEN2B syndromes.

New mutations associated with Hirschsprung disease.

INTRODUCTION: Hirschsprung Disease is caused by an impairment in cell migration from the neural crest to the gastrointestinal tract, resulting in an absence of neurons in the myenteric plexus. Many mutations in several genes have been associated to Hirschsprung disease; most of them affecting the RET proto-oncogen pathway. The purpose of this study is the description of novel and known mutations in genes associated to Hirschsprung disease and their prognostic implications. MATERIAL AND METHODS: Retrospective analysis of patients with Hirschsprung disease and positive genetic studies evaluated from 1970 to 2013. RESULTS: We found 21 positive genetic studies in the global series, 17 of them involving the RET proto-oncogene: Two of the mutations are novel and they have not been reported in the medical literature. CONCLUSIONS: The RET protooncogene is the main gene associated with Hirschsprung disease. There are still multiple unknown mutations related to the pathogenesis of the disease. The study of this gene must be part of the work-up of all patients with Hirschsprung disease, as well as their first degree relatives if the mutation is associated with MEN2A and MEN2B syndromes.

Variabilidad en la presentación clínica en la enfermedad de Pompe: evolución tras terapia de reemplazo enzimático / Variability in the clinical presentation of Pompe disease: development following enzyme replacement therapy

Introducción. La enfermedad de Pompe es un trastorno generalizado progresivo producido por el déficit de la enzima alfaglucosidasa ácida (AGA) de los lisosomas. Se presentan tres casos manifestados de forma muy diferente y tratados con terapia enzimática sustitutiva (TES), con evolución favorable. Casos clínicos. Caso 1: varón de 3 meses, con debilidad y rechazo de la alimentación, hepatomegalia leve, ligera macroglosia e hipotonía, y aumento de las enzimas musculares. Caso 2: varón de 5 meses, con retraso del desarrollo motor, sordera neurosensorial grave, trastornos respiratorios de repetición de evolución tórpida, hipotonía y leve elevación de la creatincinasa. Caso 3: varón de 22 años con disnea progresiva, con antecedentes de elevación de la creatincinasa y las transaminasas, e hipercolesterolemia. Sufrió insuficiencia respiratoria grave que precisó intubación endotraqueal. La biopsia muscular presentó depósitos de glucógeno sugestivos de la enfermedad. En los tres casos, el estudio electromiográfico dio un patrón característico, con descargas pseudomiotónicas, y se confirmó el déficit de AGA en los linfocitos. Se encontró una mutación en un caso y dos mutaciones en los otros dos. Todos recibieron TES con evolución favorable: desaparición de las alteraciones cardíacas en el caso 1, mejoría en los hitos motores en los dos casos infantiles y retirada del respirador en el caso 3. Conclusión. La enfermedad de Pompe tiene una amplia variabilidad en la expresión clínica. La TES consigue una buena respuesta, especialmente en las formas infantiles. La supervivencia a largo plazo de las formas infantiles tratadas permitirá conocer más aspectos del curso de la enfermedad (AU)

Introduction. Pompe disease is a generalized progressive disease caused by a deficiency of the lysosome enzyme acid alphaglucosidase (GAA). We present three cases with different clinical symptomatology and treated with enzyme replacement therapy (ERT) with positive evolution. Case reports. Case 1: three-month old male, with weakness and rejecting meals; mild hepatomegaly, discrete macroglossia and muscular hypotony; and increased muscular enzymes. Case 2: five-month old male, with delayed motor development, severe neurosensory deafness, and respiratory disorder of difficult evolution; muscular hypotony; and mild increase in creatine kinase. Case 3: 22-year old male, with progressive dyspnea, with history of increased creatine kinase and transaminases, and hypercholesterolemia. He suffered from severe respiratory failure requiring endotraqueal intubation Muscular biopsy showed glycogen storage suggestive of Pompe disease. In the three cases, the EMG showed a characteristic pattern with pseudomyotonic discharges and the deficiency in GAA was confirmed in lymphocytes. One single mutation was observed in one case and two in the other two cases. Every patient received ERT showing a favorable evolution; with disappearance of cardiac disorders in case 1, improvement in motor development in both infants and no longer need for mechanical ventilation in case 3. Conclusion. Pompe disease has a wide variability in clinical expression. ERT achieves a good response, especially in infant forms of the disease. The survival of treated patients with these Pompe disease forms will allow knowing further the course of the disease (AU)

[Variability in the clinical presentation of Pompe disease: development following enzyme replacement therapy]. / Variabilidad en la presentación clínica en la enfermedad de Pompe: evolución tras terapia de reemplazo enzimático.

INTRODUCTION: Pompe disease is a generalized progressive disease caused by a deficiency of the lysosome enzyme acid alpha-glucosidase (GAA). We present three cases with different clinical symptomatology and treated with enzyme replacement therapy (ERT) with positive evolution. CASE REPORTS: Case 1: three-month old male, with weakness and rejecting meals; mild hepatomegaly, discrete macroglossia and muscular hypotony; and increased muscular enzymes. Case 2: five-month old male, with delayed motor development, severe neurosensory deafness, and respiratory disorder of difficult evolution; muscular hypotony; and mild increase in creatine kinase. Case 3: 22-year old male, with progressive dyspnea, with history of increased creatine kinase and transaminases, and hypercholesterolemia. He suffered from severe respiratory failure requiring endotraqueal intubation Muscular biopsy showed glycogen storage suggestive of Pompe disease. In the three cases, the EMG showed a characteristic pattern with pseudomyotonic discharges and the deficiency in GAA was confirmed in lymphocytes. One single mutation was observed in one case and two in the other two cases. Every patient received ERT showing a favorable evolution; with disappearance of cardiac disorders in case 1, improvement in motor development in both infants and no longer need for mechanical ventilation in case 3. CONCLUSION: Pompe disease has a wide variability in clinical expression. ERT achieves a good response, especially in infant forms of the disease. The survival of treated patients with these Pompe disease forms will allow knowing further the course of the disease.

TITLE: Variabilidad en la presentacion clinica en la enfermedad de Pompe: evolucion tras terapia de reemplazo enzimatico.Introduccion. La enfermedad de Pompe es un trastorno generalizado progresivo producido por el deficit de la enzima alfa-glucosidasa acida (AGA) de los lisosomas. Se presentan tres casos manifestados de forma muy diferente y tratados con terapia enzimatica sustitutiva (TES), con evolucion favorable. Casos clinicos. Caso 1: varon de 3 meses, con debilidad y rechazo de la alimentacion, hepatomegalia leve, ligera macroglosia e hipotonia, y aumento de las enzimas musculares. Caso 2: varon de 5 meses, con retraso del desarrollo motor, sordera neurosensorial grave, trastornos respiratorios de repeticion de evolucion torpida, hipotonia y leve elevacion de la creatincinasa. Caso 3: varon de 22 años con disnea progresiva, con antecedentes de elevacion de la creatincinasa y las transaminasas, e hipercolesterolemia. Sufrio insuficiencia respiratoria grave que preciso intubacion endotraqueal. La biopsia muscular presento depositos de glucogeno sugestivos de la enfermedad. En los tres casos, el estudio electromiografico dio un patron caracteristico, con descargas pseudomiotonicas, y se confirmo el deficit de AGA en los linfocitos. Se encontro una mutacion en un caso y dos mutaciones en los otros dos. Todos recibieron TES con evolucion favorable: desaparicion de las alteraciones cardiacas en el caso 1, mejoria en los hitos motores en los dos casos infantiles y retirada del respirador en el caso 3. Conclusion. La enfermedad de Pompe tiene una amplia variabilidad en la expresion clinica. La TES consigue una buena respuesta, especialmente en las formas infantiles. La supervivencia a largo plazo de las formas infantiles tratadas permitira conocer mas aspectos del curso de la enfermedad.

The alpha-galactosidase A p.Arg118Cys variant does not cause a Fabry disease phenotype: data from individual patients and family studies.

Lysosomal α-galactosidase A (α-Gal) is the enzyme deficient in Fabry disease (FD), an X-linked glycosphingolipidosis caused by pathogenic mutations affecting the GLA gene. The early-onset, multi-systemic FD classical phenotype is associated with absent or severe enzyme deficiency, as measured by in vitro assays, but patients with higher levels of residual α-Gal activity may have later-onset, more organ-restricted clinical presentations. A change in the codon 118 of the wild-type α-Gal sequence, replacing basic arginine by a potentially sulfhydryl-binding cysteine residue - GLA p.(Arg118Cys) -, has been recurrently described in large FD screening studies of high-risk patients. Although the Cys118 allele is associated with high residual α-Gal activity in vitro, it has been classified as a pathogenic mutation, mainly on the basis of theoretical arguments about the chemistry of the cysteine residue. However its pathogenicity has never been convincingly demonstrated by pathology criteria. We reviewed the clinical, biochemical and histopathology data obtained from 22 individuals of Portuguese and Spanish ancestry carrying the Cys118 allele, including 3 homozygous females. Cases were identified either on the differential diagnosis of possible FD manifestations and on case-finding studies (n=11; 4 males), or on unbiased cascade screening of probands' close relatives (n=11; 3 males). Overall, those data strongly suggest that the GLA p.(Arg118Cys) variant does not segregate with FD clinical phenotypes in a Mendelian fashion, but might be a modulator of the multifactorial risk of cerebrovascular disease. The Cys118 allelic frequency in healthy Portuguese adults (n=696) has been estimated as 0.001, therefore not qualifying for "rare" condition.