Beyond genetics: Deciphering the impact of missense variants in CAD deficiency.

CAD is a large, 2225 amino acid multienzymatic protein required for de novo pyrimidine biosynthesis. Pathological CAD variants cause a developmental and epileptic encephalopathy which is highly responsive to uridine supplements. CAD deficiency is difficult to diagnose because symptoms are nonspecific, there is no biomarker, and the protein has over 1000 known variants. To improve diagnosis, we assessed the pathogenicity of 20 unreported missense CAD variants using a growth complementation assay that identified 11 pathogenic variants in seven affected individuals; they would benefit from uridine treatment. We also tested nine variants previously reported as pathogenic and confirmed the damaging effect of seven. However, we reclassified two variants as likely benign based on our assay, which is consistent with their long-term follow-up with uridine. We found that several computational methods are unreliable predictors of pathogenic CAD variants, so we extended the functional assay results by studying the impact of pathogenic variants at the protein level. We focused on CAD's dihydroorotase (DHO) domain because it accumulates the largest density of damaging missense changes. The atomic-resolution structures of eight DHO pathogenic variants, combined with functional and molecular dynamics analyses, provided a comprehensive structural and functional understanding of the activity, stability, and oligomerization of CAD's DHO domain. Combining our functional and protein structural analysis can help refine clinical diagnostic workflow for CAD variants in the genomics era.

Lipomatous atrial septal hypertrophy associated with adrenocorticotropin hormone administration in an infant with West syndrome.

We present the rare case of lipomatous atrial septal hypertrophy associated with adrenocorticotropin hormone therapy in an infant with West syndrome, highlighting their relatively benign nature and good prognosis in children, and the relevance of the differential diagnosis with more dangerous cardiac masses in order to avoid aggressive diagnostic and therapeutic interventions.

Family study of a novel mutation of mucopolysaccharidosis type VI with a severe phenotype and good response to enzymatic replacement therapy: Case report.

RATIONALE: Mucopolysaccharidosis type VI (MPS VI) or Maroteaux-Lamy syndrome is produced by the deficiency of the enzyme arylsulfatase B, responsible for the hydrolysis of N-acetyl-D-galactosamine, chondroitin sulfate, and dermatan sulfate. PATIENT CONCERNS: A 3-year-old male with Moroccan origins is the index case. He had healthy consanguineous parents and 4 healthy brothers and sisters. The patient showed a wide spectrum of symptoms including skeletal dysplasia and short stature with elevated glycosaminoglycans (GAGs) in urine. DIAGNOSES, INTERVENTIONS, AND OUTCOMES: GAGs were quantified by spectrometry method with 1,9-dimethylen blue in 24-hour urine samples. The qualitative analysis of urine GAGs was obtained by thin-layer chromatography to determine the predominant presence of dermatan sulfate. The activities of both arylsulfatase B and beta-galactosidase as well as genetic studies were performed in dried blood spots. The genetic study was performed with deoxyribonucleic acid by massive sequencing a of lisosomal storage diseases. Results showed a new mutation c.263A > C with the severe phenotype in homozygous in the patient. The familiar study of ARSB and GLB1 genes presented some asymptomatic SNPs but with a discrete decrease in the activity of arylsulfatase B and beta-galactosidase. After an early detection by pediatricians, and both enzymatic and genetic confirmation, the patient had a good response to substitutive enzymatic treatment with galsulfase. LESSONS: Mucoplysaccharidosis type VI is an autosomal recessive rare disease characterized by a lysosomal storage disorder. Although a number of mutations have been already associated to the disease, we have found a new mutation located in the arylsulfatase B enzyme gene. We have described that this mutation is the ultimate cause of a severe presentation of the disease.

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.

[Hypomyelination with atrophy of the basal ganglia and cerebellum. Contribution of two new cases to a recently reported entity]. / Hipomielinización con atrofia de ganglios basales y de cerebelo. Aportación de dos nuevos casos a una entidad de descripción reciente.

INTRODUCTION: Hypomyelination with atrophy of the basal ganglia and cerebellum (H-ABC) is a rare condition that has only recently been reported. Here we present two new cases belonging to the same family. CASE REPORTS: Case 1: 17-month-old boy with severe underdevelopment in all areas, absence of language and eye contact. The examination revealed microcephaly with spastic tetraparesis. A magnetic resonance imaging scan showed predominantly vermian atrophy of the cerebellum with loss of volume of both nuclei of the putamen and the head of the caudate, and a pattern of hypomyelination of the white matter. Electromyography recording highlighted the presence of a predominantly motor pattern of chronic polyneuropathy. Homovallinic acid and 5-hydroxyindoleacetic acid values were lower than usual. Treatment with levodopa/carbidopa was not effective. Case 2: 11-month-old girl, the sister of the boy in the previous case. The patient presented severe underdevelopment in all areas and microcephaly with spastic tetraparesis was detected in the clinical examination. Magnetic resonance imaging of the head showed findings that could be superimposed upon those of the brother, with hypomyelination, cerebellar atrophy and involvement of the putamen and both caudates; electromyography findings were consistent with motor polyneuropathy of a demyelinating nature. Homovallinic acid and 5-hydroxyindoleacetic acid values in cerebrospinal fluid were lower than usual. Treatment with levodopa/carbidopa was ineffective. CONCLUSIONS: These two new cases help characterise this condition better and reinforce the hypothesis of the genetic origin of the syndrome, given that the two cases occurred in the same family.

TITLE: Hipomielinizacion con atrofia de ganglios basales y de cerebelo. Aportacion de dos nuevos casos a una entidad de descripcion reciente.Introduccion. La hipomielinizacion con atrofia de ganglios basales y de cerebelo (H-ABC) es una rara entidad descrita recientemente. Se presentan dos nuevos casos pertenecientes a una misma familia. Casos clinicos. Caso 1: niño de 17 meses con retraso grave en todas las areas, ausencia de lenguaje y de contacto visual. En la exploracion destacaba una microcefalia con tetraparesia espastica. En la resonancia magnetica cerebral se apreciaba atrofia cerebelosa de predominio vermiano con perdida de volumen de ambos nucleos del putamen y la cabeza del caudado, y patron de hipomielinizacion de la sustancia blanca. En la electromiografia se objetivo un patron de polineuropatia cronica de predominio motor. Presento un descenso de los valores de acido homovalinico y de acido 5-hidroxindolacetico. El tratamiento con levodopa/carbidopa no fue efectivo. Caso 2: niña de 11 meses, hermana del caso anterior. Presentaba un retraso grave en todas las areas y en la exploracion clinica se detecto una microcefalia con tetraparesia espastica. La resonancia magnetica cerebral mostro hallazgos superponibles a los del hermano, con hipomielinizacion, atrofia cerebelosa y afectacion putaminal y de ambos caudados; en la electromiografia, hallazgos compatibles con polineuropatia motora de caracter desmielinizante. Presento un descenso de los valores de acido homovalinico y acido 5-hidroxindolacetico en el liquido cefalorraquideo. El tratamiento con levodopa/carbidopa resulto ineficaz. Conclusiones. Estos dos nuevos casos ayudan a caracterizar mejor esta entidad y refuerzan la hipotesis del origen genetico del sindrome, dado que se trata de dos casos pertenecientes a una misma familia.

Hipomielinización con atrofia de ganglios basales y de cerebelo. Aportación de dos nuevos casos a una entidad de descripción reciente / Hypomyelination with atrophy of the basal ganglia and cerebellum. Contribution of two new cases to a recently reported entity

Introducción. La hipomielinización con atrofia de ganglios basales y de cerebelo (H-ABC) es una rara entidad descrita recientemente. Se presentan dos nuevos casos pertenecientes a una misma familia. Casos clínicos. Caso 1: niño de 17 meses con retraso grave en todas las áreas, ausencia de lenguaje y de contacto visual. En la exploración destacaba una microcefalia con tetraparesia espástica. En la resonancia magnética cerebral se apreciaba atrofia cerebelosa de predominio vermiano con pérdida de volumen de ambos núcleos del putamen y la cabeza del caudado, y patrón de hipomielinización de la sustancia blanca. En la electromiografía se objetivó un patrón de polineuropatía crónica de predominio motor. Presentó un descenso de los valores de ácido homovalínico y de ácido 5-hidroxindolacético. El tratamiento con levodopa/carbidopa no fue efectivo. Caso 2: niña de 11 meses, hermana del caso anterior. Presentaba un retraso grave en todas las áreas y en la exploración clínica se detectó una microcefalia con tetraparesia espástica. La resonancia magnética cerebral mostró hallazgos superponibles a los del hermano, con hipomielinización, atrofia cerebelosa y afectación putaminal y de ambos caudados; en la electromiografía, hallazgos compatibles con polineuropatía motora de carácter desmielinizante. Presentó un descenso de los valores de ácido homovalínico y ácido 5-hidroxindolacético en el líquido cefalorraquídeo. El tratamiento con levodopa/carbidopa resultó ineficaz. Conclusiones. Estos dos nuevos casos ayudan a caracterizar mejor esta entidad y refuerzan la hipótesis del origen genético del síndrome, dado que se trata de dos casos pertenecientes a una misma familia (AU)

Introduction. Hypomyelination with atrophy of the basal ganglia and cerebellum (H-ABC) is a rare condition that has only recently been reported. Here we present two new cases belonging to the same family. Case reports. Case 1: 17-month-old boy with severe underdevelopment in all areas, absence of language and eye contact. The examination revealed microcephaly with spastic tetraparesis. A magnetic resonance imaging scan showed predominantly vermian atrophy of the cerebellum with loss of volume of both nuclei of the putamen and the head of the caudate, and a pattern of hypomyelination of the white matter. Electromyography recording highlighted the presence of a predominantly motor pattern of chronic polyneuropathy. Homovallinic acid and 5-hydroxyindoleacetic acid values were lower than usual. Treatment with levodopa/carbidopa was not effective. Case 2: 11-month-old girl, the sister of the boy in the previous case. The patient presented severe underdevelopment in all areas and microcephaly with spastic tetraparesis was detected in the clinical examination. Magnetic resonance imaging of the head showed findings that could be superimposed upon those of the brother, with hypomyelination, cerebellar atrophy and involvement of the putamen and both caudates; electromyography findings were consistent with motor polyneuropathy of a demyelinating nature. Homovallinic acid and 5-hydroxyindoleacetic acid values in cerebrospinal fluid were lower than usual. Treatment with levodopa/carbidopa was ineffective. Conclusions. These two new cases help characterise this condition better and reinforce the hypothesis of the genetic origin of the syndrome, given that the two cases occurred in the same family (AU)

Infant botulism in Andalusia (Southern Spain).

BACKGROUND: Infant botulism (IB) is caused by the intestinal colonization by Clostridium botulinum in the first year of life and its subsequent production of neurotoxins. Traditionally, IB has been associated to honey consumption. IB cases tend to cluster in geographic regions. In Europe, IB is a rare disorder. From 1976 through 2006, 65 cases were identified in 13 European countries. In Spain, in the last 15 years, most of the cases have been reported in one region, Andalusia (Southern Spain). A specific treatment for IB type A and type B (BabyBIG) is available outside of the United States since 2005. METHODS: and aims: We performed a retrospective review of IB cases detected in Andalusia since 1997 and compare them with the cases of IB reported in Europe. RESULTS: We identified 11 confirmed cases of IB in Andalusia since 1997, and 14 cases in Spain. Nine out of 11 cases were detected since 2007; none of these infants had been exposed to honey consumption. One case in 1997 and another in 2000 were associated to honey. Two cases were treated with BabyBIG in 2007. In the period 2006-2012 the cases of IB reported in Europe were 54. CONCLUSIONS: We identified a considerable increase in the incidence of IB since 2006. A tendency to a reduction in the number of cases of IB linked to honey consumption has also been identified. An increase in the exposure to these bacteria from the environment could be presumed. Clinicians should maintain a high index of suspicion for this treatable disorder.

Guía clínica de la enfermedad de Pompe de inicio tardío / Clinical guidelines for late-onset Pompe disease

Resumen. Hasta 2006, la enfermedad de Pompe o glucogenosis tipo II era una enfermedad incurable y con tratamiento meramente paliativo. El desarrollo de la terapia de sustitución con la enzima α-glucosidasa recombinante humana ha constituido el primer tratamiento específico para esta enfermedad. El objetivo de esta guía es servir de referencia en el manejo de la variedad de inicio tardío de la enfermedad de Pompe, es decir, la que aparece después del primer año de vida. En la guía, un grupo de expertos españoles hace recomendaciones específicas en cuanto a diagnóstico, seguimiento y tratamiento de esta enfermedad. En cuanto al diagnóstico, el método de la muestra en sangre seca es imprescindible como primer paso para el diagnóstico de la enfermedad de Pompe, y el diagnóstico de confirmación de la enfermedad de Pompe debe realizarse mediante un estudio de la actividad enzimática en muestra líquida en linfocitos aislados o mediante el análisis mutacional del gen de la alfa-glucosidasa. En cuanto al tratamiento de la enfermedad con terapia de sustitución enzimática, los expertos afirman que es eficaz en la mejoría o estabilización de la función motora y pulmonar, y debe iniciarse cuando aparezcan los síntomas atribuibles a la enfermedad de Pompe (AU)

Summary. Before 2006, Pompe disease or glycogenosis storage disease type II was an incurable disease whose treatment was merely palliative. The development of a recombinant human alpha-glucosidase enzymatic replacement therapy has become the first specific treatment for this illness. The aim of this guide is to serve as reference for the management of the late-onset Pompe disease, the type of Pompe disease that develops after one year of age. In the guide a group of Spanish experts make specific recommendations about diagnosis, follow-up and treatment of this illness. With regard to diagnosis, the dried blood spots method is essential as the first step for the diagnosis of Pompe disease. The confirmation of the diagnosis of Pompe disease must be made by means of an study of enzymatic activity in isolated lymphocytes or a mutation analysis of the alpha-glucosidase gene. With regard to treatment with enzymatic replacement therapy, the experts say that is effective improving or stabilizating the motor function and the respiratory function and it must be introduced when the first symptoms attributable to Pompe disease appear (AU)