Study of paediatric patients with the clinical and biochemical phenotype of glucose transporter type 1 deficiency syndrome.

INTRODUCTION: Glucose transporter type 1 (GLUT1) deficiency syndrome may present a range of phenotypes, including epilepsy, intellectual disability, and movement disorders. The majority of patients present low CSF glucose levels and/or defects in the SLC2A1 gene; however, some patients do not present low CSF glucose or SLC2A1 mutations, and may have other mutations in other genes with compatible phenotypes. AIMS: We describe the clinical, biochemical, and genetic characteristics of the disease and perform a univariate analysis of a group of patients with clinical and biochemical phenotype of GLUT1 deficiency syndrome, with or without SLC2A1 mutations. MATERIAL AND METHODS: The study included 13 patients meeting clinical and biochemical criteria for GLUT1 deficiency syndrome. SLC2A1 sequencing and multiplex ligation-dependent probe amplification were performed; exome sequencing was performed for patients with negative results. RESULTS: Six patients presented the classic phenotype; 2 paroxysmal dyskinesia, 2 complex movement disorders, 2 early-onset absence seizures, and one presented drug-resistant childhood absence epilepsy. Six patients were positive for SLC2A1 mutations; in the other 5, another genetic defect was identified. No significant differences were observed between the 2 groups for age of onset, clinical presentation, microcephaly, intellectual disability, or response to ketogenic diet. Patients with SLC2A1 mutations presented more clinical changes in relation to diet (66.7%, vs 28.6% in the SLC2A1-negative group) and greater persistence of motor symptoms (66% vs 28.6%); these differences were not statistically significant. Significant differences were observed for CSF glucose level (34.5 vs 46mg/dL, P=.04) and CSF/serum glucose ratio (0.4 vs 0.48, P<.05). CONCLUSIONS: GLUT1 deficiency syndrome may be caused by mutations to genes other than SLC2A1 in patients with compatible phenotype, low CSF glucose level, and good response to the ketogenic diet.

Estudio de pacientes pediátricos con fenotipo clínico y bioquímico de síndrome de déficit de transportador de glucosa cerebral (GLUT-1) / Study of paediatric patients with the clinical and biochemical phenotype of glucose transporter type 1 deficiency syndrome

Introducción: El síndrome de déficit del transportador de glucosa cerebral (GLUT1DS) puede presentar fenotipos variados, incluyendo epilepsia, déficit intelectual y trastorno del movimiento. La mayoría presenta hipoglucorraquia y/o defectos en el gen SLC2A1, aunque existen pacientes sin hipoglucorraquia y otros con genética de SLC2A1-negativa, o con defectos en otros genes y fenotipo compatible. Objetivos: Describir las características clínicas, bioquímicas y genéticas y realizar un análisis univariante de un grupo de pacientes con fenotipo clínico y bioquímico de GLUT1DS, con o sin genética SLC2A1-positiva. Material y métodos: Se incluyeron 13 pacientes con criterios clínico-bioquímicos de GLUT1DS. Se realizó secuenciación de SLC2A1 y MLPA. En los casos negativos se realizó exoma clínico. Resultados: Seis presentaron fenotipo clásico, 2 discinesia paroxística, 2 trastornos del movimiento complejo, 2 ausencias precoces y otro presentó epilepsia con ausencias infantiles refractaria a farmacoterapia. Seis fueron SLC2A1-positivos. Y en 5 de los SLC2A1-negativos se identificó otro defecto genético. No hubo diferencias significativas entre los dos grupos en edad de inicio, presentación clínica, microcefalia, discapacidad intelectual ni respuesta a dieta cetogénica. De forma no significativa, los pacientes SCL2A1-positivos presentaron más cambios clínicos en relación con la ingesta (66,7% vs. 28,6%) y mayor persistencia de síntomas motores (66% vs. 28,6%). De forma significativa, presentaron menor glucorraquia (34,5 mg/dl vs. 46 mg/dl, p = 0,04) e índice glucorraquia/glucemia más bajo (0,4 vs. 0,48, p = 0,05) que los SLC2A1-negativos. Conclusiones: GLUT1DS puede ser causado por defectos genéticos en otros genes diferentes de SLC2A1 en pacientes con fenotipo compatible, hipoglucorraquia y buena respuesta a dieta cetogénica. (AU)

Introduction: Glucose transporter type 1 (GLUT1) deficiency syndrome may present a range of phenotypes, including epilepsy, intellectual disability, and movement disorders. The majority of patients present low CSF glucose levels and/or defects in the SLC2A1 gene; however, some patients do not present low CSF glucose or SLC2A1 mutations, and may have other mutations in other genes with compatible phenotypes. Aims: We describe the clinical, biochemical, and genetic characteristics of the disease and perform a univariate analysis of a group of patients with clinical and biochemical phenotype of GLUT1 deficiency syndrome, with or without SLC2A1 mutations. Material and methods: The study included 13 patients meeting clinical and biochemical criteria for GLUT1 deficiency syndrome. SLC2A1 sequencing and multiplex ligation-dependent probe amplification were performed; exome sequencing was performed for patients with negative results. Results: Six patients presented the classic phenotype; 2 paroxysmal dyskinesia, 2 complex movement disorders, 2 early-onset absence seizures, and one presented drug-resistant childhood absence epilepsy. Six patients were positive for SLC2A1mutations; in the other 5, another genetic defect was identified. No significant differences were observed between the 2 groups for age of onset, clinical presentation, microcephaly, intellectual disability, or response to ketogenic diet. Patients ith SLC2A1 mutations presented more clinical changes in relation to diet (66.7% vs. 28.6% in the SLC2A1-negative group) and greater persistence of motor symptoms (66% vs. 28.6%); these differences were not statistically significant. Significant differences were observed for CSF glucose level (34.5 vs. 46 mg/dL, P = .04) and CSF/serum glucose ratio (0.4 vs. 0.48, P < .05). [...] (AU)

Proteostasis regulators as potential rescuers of PMM2 activity.

Phosphomannomutase 2 deficiency (PMM2-CDG) is the most common N-glycosylation disorder. To date there is no treatment. Following the identification of a number of destabilizing pathogenic variants, our group suggested PMM2-CDG to be a conformational disease. The aim of the present study was to evaluate the possible use of proteostasis network regulators to increase the stability, and subsequently the enzymatic activity, of misfolded PMM2 mutant proteins. Patient-derived fibroblasts transduced with their own PMM2 folding or oligomerization variants were treated with different concentrations of the proteostasis regulators celastrol or MG132. Celastrol treatment led to a significant increase in mutant PMM2 protein concentration and activity, while MG132 had a small effect on protein concentration only. The increase in enzymatic activity with celastrol correlated with an increase in the transcriptional and proteome levels of the heat shock proteins Hsp90 and Hsp70. The use of specific Hsp70 or Hsp90 inhibitors showed the positive effect of celastrol on PMM2 stability and activity to occur through Hsp90-driven modulation of the proteostasis network. The synergistic effect of celastrol and a previously described pharmacological chaperone was also examined, and a mutation-dependent synergistic effect on PMM2 activity was noted. These results provide proof-of-concept regarding the potential treatment of PMM2-CDG by proteostasis regulators, either alone or in combination with pharmacological chaperones.

¿Cómo se sospecha una fibrosis pulmonar idiopática en la atención primaria de salud? / How is idiopathic pulmonary fibrosis suspected in primary health care?

La fibrosis pulmonar idiopática (FPI) es una enfermedad pulmonar de sintomatología inespecífica. La tos crónica y disnea progresivas en adultos mayores fumadores o exfumadores son los síntomas y características clínicas más frecuentes. Por lo tanto, es usual que el diagnóstico sea tardío. La atención primaria constituye el primer contacto del paciente con el sistema de salud. Por esto es necesaria la entrega de toda la información posible a los médicos, enfermeras y kinesiólogos que atienden adultos con problemas respiratorios, ya que sólo se diagnosticará FPI si se piensa en FPI.

Idiopathic pulmonary fibrosis (IPF) is a lung disease of nonspecific symptomatology. Progressive chronic cough and dyspnea in older smokers or ex-smokers are the most frequent symptoms and clinical features. Therefore, it is usual for the diagnosis to be late. Primary care constitutes the patient's first contact with the health system. Therefore, it is necessary to deliver all possible information to physicians, nurses and physical therapists who care for adults with respiratory problems, since IPF will only be diagnosed if FPI is considered.

Study of paediatric patients with the clinical and biochemical phenotype of glucose transporter type 1 deficiency syndrome. / Estudio de pacientes pediátricos con fenotipo clínico y bioquímico de síndrome de déficit de transportador de glucosa cerebral (GLUT-1).

INTRODUCTION: Glucose transporter type 1 (GLUT1) deficiency syndrome may present a range of phenotypes, including epilepsy, intellectual disability, and movement disorders. The majority of patients present low CSF glucose levels and/or defects in the SLC2A1 gene; however, some patients do not present low CSF glucose or SLC2A1 mutations, and may have other mutations in other genes with compatible phenotypes. AIMS: We describe the clinical, biochemical, and genetic characteristics of the disease and perform a univariate analysis of a group of patients with clinical and biochemical phenotype of GLUT1 deficiency syndrome, with or without SLC2A1 mutations. MATERIAL AND METHODS: The study included 13 patients meeting clinical and biochemical criteria for GLUT1 deficiency syndrome. SLC2A1 sequencing and multiplex ligation-dependent probe amplification were performed; exome sequencing was performed for patients with negative results. RESULTS: Six patients presented the classic phenotype; 2 paroxysmal dyskinesia, 2 complex movement disorders, 2 early-onset absence seizures, and one presented drug-resistant childhood absence epilepsy. Six patients were positive for SLC2A1 mutations; in the other 5, another genetic defect was identified. No significant differences were observed between the 2 groups for age of onset, clinical presentation, microcephaly, intellectual disability, or response to ketogenic diet. Patients with SLC2A1 mutations presented more clinical changes in relation to diet (66.7% vs. 28.6% in the SLC2A1-negative group) and greater persistence of motor symptoms (66% vs. 28.6%); these differences were not statistically significant. Significant differences were observed for CSF glucose level (34.5 vs. 46mg/dL, P=.04) and CSF/serum glucose ratio (0.4 vs. 0.48, P<.05). CONCLUSIONS: GLUT1 deficiency syndrome may be caused by mutations to genes other than SLC2A1 in patients with compatible phenotype, low CSF glucose level, and good response to the ketogenic diet.

Miastenia congénita y defecto congénito de la glucosilación por mutaciones en el gen DPAGT1 / Congenital myasthenia and congenital disorders of glycosylation caused by mutations in the DPAGT1 gene

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Inferior Vena Cava Agenesis: An Unusual Cause of Deep Vein Thrombosis and Pulmonary Embolism in Young Adult Patients.

INTRODUCTION: Inferior vena cava agenesis (IVCA) is one of the many anomalies of this vessel. It is one of the most uncommon anomalies, with an estimated prevalence of 0.0005-1% in the general population. Around 5% of the patients younger than 30 years with a diagnosis of deep vein thrombosis (DVT) have a total or segmental IVCA. REPORT: Here two unique cases of young and previously healthy male patients are reported: one with bilateral lower extremity DVT, the second with lower extremity DVT and pulmonary embolism. Both patients were found to have segmental agenesis of the inferior vena cava on computed tomography angiography (CTA). Treatment consisted of ultrasound enhanced thrombolysis (EKOS + alteplase) and venous angioplasty. Both patients were discharged with long-term (up to 24 months) oral anticoagulation and compression stockings. Follow up at 3 and 12 months revealed no new thrombotic episode. DISCUSSION: IVCA can be asymptomatic but the majority of the symptomatic patients present with DVT. IVCA confers a risk factor for DVT. IVCA should be considered and ruled out as a rare but important risk factor and cause of DVT in previously young healthy patients. Once diagnosed, aggressive treatment must be started because of the high risk of post-thrombotic syndrome.

Protein misfolding diseases: Prospects of pharmacological treatment.

Protein misfolding has been linked to numerous inherited diseases. Loss- and gain-of-function mutations (common features of genetic diseases) may cause the destabilization of proteins, leading to alterations in their properties and/or cellular location, resulting in their incorrect functioning. Misfolded proteins can, however, be rescued via the use of proteostasis regulators and/or pharmacological chaperones, suggesting that treatments with small molecules might be developed for a range of genetic diseases. This work describes the potential of these small molecules in this respect, including for the treatment of congenital disorder of glycosylation (CDG) due to phosphomannomutase 2 deficiency (PMM2-CDG).

Four Years' Experience in the Diagnosis of Very Long-Chain Acyl-CoA Dehydrogenase Deficiency in Infants Detected in Three Spanish Newborn Screening Centers.

Identification of very long-chain acyl-CoA dehydrogenase deficiency is possible in the expanded newborn screening (NBS) due to the increase in tetradecenoylcarnitine (C14:1) and in the C14:1/C2, C14:1/C16, C14:1/C12:1 ratios detected in dried blood spots. Nevertheless, different confirmatory tests must be performed to confirm the final diagnosis. We have revised the NBS results and the results of the confirmatory tests (plasma acylcarnitine profiles, molecular findings, and lymphocytes VLCAD activity) for 36 cases detected in three Spanish NBS centers during 4 years, correlating these with the clinical outcome and treatment. Our aim was to distinguish unambiguously true cases from disease carriers in order to obtain useful diagnostic information for clinicians that can be applied in the follow-up of neonates identified by NBS.Increases in C14:1 and of the different ratios, the presence of two pathogenic mutations, and deficient enzyme activity in lymphocytes (<12% of the intra-assay control) identified 12 true-positive cases. These cases were given nutritional therapy and all of them are asymptomatic, except one. Seventeen individuals were considered disease carriers based on the mild increase in plasma C14:1, in conjunction with the presence of only one mutation and/or intermediate residual activity (18-57%). In addition, seven cases were classified as false positives, with normal biochemical parameters and no mutations in the exonic region of ACADVL. All these carriers and the false positive cases remained asymptomatic. The combined evaluation of the acylcarnitine profiles, genetic results, and residual enzyme activities have proven useful to definitively classify individuals with suspected VLCAD deficiency into true-positive cases and carriers, and to decide which cases need treatment.

Impacto de la docencia en el tiempo de estadía hospitalaria de pacientes con patologías prevalentes en un hospital universitario / The impact of teaching on hospital stay duration in patients with common pathology in a university hospital

INTRODUCCIÓN: Desde la creación de la primera Escuela de Medicina en Chile, tanto hospitales públicos y establecimientos de atención primaria, han desarrollado la relación "docente-asistencial". Ésta relación se ha visto afectada, ya que actualmente las hospitalizaciones reflejan patologías graves y complejas, requiriendo mayor trabajo y tiempo por paciente, en desmedro del tiempo dedicado a la docencia o viceversa, si se dedica más tiempo a la docencia sería en desmedro de la evaluación clínica del paciente. OBJETIVO: Conocer el impacto de la relación docente asistencial en el tiempo de estadía de los pacientes en el servicio de Medicina del Hospital Carlos Van Buren (HCVB). Pacientes y métodos: Estudio descriptivo, que incluyó los egresos hospitalarios del HCVB del periodo Enero/2015-Agosto/2016 con diagnósticos de 4 patologías prevalentes, tanto del 4° piso (área no docente) como 7° piso (área docente) del establecimiento. Los datos se obtuvieron con la herramienta GRD y fueron analizados con el programa STATA/MP 14.0. RESULTADOS: El promedio general de días de estadía del 7° piso fue menor al del 4° piso, con un p value=0.0000. Discusión: El obtener un resultado positivo en cuanto a la disminución de estadía hospitalaria en un piso docente, alejaría el planteamiento de un impacto negativo para el paciente de la relación docente-asistencial. CONCLUSIONES: Los resultados obtenidos en este trabajo hay que interpretarlos con cuidado, ya que se hace difícil plantear que la disminución de estadía hospitalaria se deba sólo a la presencia de docencia, por lo que es necesario la realización de más estudios similares.

INTRODUCTION: Ever since the establishment of the first medical school in Chile, public hospitals and primary care establishments have combined healthcare and teaching. Hospitals nowadays handle more serious and complex pathologies, placing more demand on time and care spent on the patient, thereby reducing the time available for teaching, or if teaching time is maintained, reducing time spent on the patient´s clinical evaluation. OBJECTIVE: To elucidate the impact of healthcare combined with teaching on the length of stay in the general medicine service of Carlos van Buren Hospital. Patients and Methods:Adescriptive study of patients discharged from Carlos van Buren Hospital between January 2015 and August 2016 using diagnoses of four frequent pathologies and comparing the 4th floor (non-teaching) with the 7th floor (teaching). Data was obtained using the tool GRD (Grupos Relacionados a Diagnósticos) and analyzed using the Stata/MP 14.0 program. RESULTS: The average length of stay for patients on the 7th floor (teaching area) was shorter than that of patients on the 4th floor (non-teaching), with a p value = 0.0000. DISCUSSION: A positive result in reducing hospital stay in the teaching floor helps to dismiss the idea that combining healthcare with teaching has a negative effect on the patient. Conclusions: These results should be interpreted with care as it is unlikely the reduced stay was attributable solely to the teaching. More similar studies should be carried out.

Tyrosinemia type II: Mutation update, 11 novel mutations and description of 5 independent subjects with a novel founder mutation.

BACKGROUND: Tyrosinemia type II, also known as Richner-Hanhart Syndrome, is an extremely rare autosomal recessive disorder, caused by mutations in the gene encoding hepatic cytosolic tyrosine aminotransferase, leading to the accumulation of tyrosine and its metabolites which cause ocular and skin lesions, that may be accompanied by neurological manifestations, mostly intellectual disability. AIMS: To update disease-causing mutations and current clinical knowledge of the disease. MATERIALS AND METHODS: Genetic and clinical information were obtained from a collection of both unreported and previously reported cases. RESULTS: We report 106 families, represented by 143 individuals, carrying a total of 36 genetic variants, 11 of them not previously known to be associated with the disease. Variants include 3 large deletions, 21 non-synonymous and 5 nonsense amino-acid changes, 5 frameshifts and 2 splice variants. We also report 5 patients from Gran Canaria, representing the largest known group of unrelated families sharing the same P406L mutation. CONCLUSIONS: Data analysis did not reveal a genotype-phenotype correlation, but stressed the need of early diagnosis: All patients improved the oculocutaneous lesions after dietary treatment but neurological symptoms prevailed. The discovery of founder mutations in isolated populations, and the benefits of early intervention, should increase diagnostic awareness in newborns.

Amphetamine treatment affects the extra-hypothalamic vasopressinergic system in a sex- and nucleus-dependent manner.

The lateral septum (LS), a brain structure implicated in addictive behaviours, regulates the activation of dopaminergic neurones in the ventral tegmental area. Vasopressinergic projections from the extended amygdala to the LS, which are sexually dimorphic, could be responsible for the vulnerability to addiction in a sex-dependent manner. The present study aimed to investigate the modulatory effects of amphetamine (AMPH) on the expression of vasopressin (AVP) in the vasopressinergic extra-hypothalamic system in sensitised male and female rats. Adult male and female Sprague-Dawley rats underwent an AMPH-locomotor sensitisation protocol. Acute AMPH increased AVP mRNA expression in the medial amygdala (MeA), whereas AMPH-induced sensitisation increased AVP mRNA expression in the bed nucleus of the stria terminalis (BNST) only in females. Interestingly, the increase in AVP expression in BNST was higher in oestrus females compared to dioestrus females and acute AMPH resulted in a decrease in AVP levels in the LS, only in males. Thus, there are complex and region-specific interactions between AMPH and the extra-hypothalamic vasopressinergic system in the brain, underlying possible alterations in different behaviours caused by acute and chronic AMPH exposure.

Impacto de las filtraciones anastomóticas en cirugía colorrectal / Impact of anastomotic leak in colorectal surgery

Introducción: La filtración de anastomosis es una de las complicaciones de mayor impacto en cirugía colorrectal. Objetivo: Analizar la frecuencia e impacto de las filtraciones anastomóticas en cirugía laparoscópica colorrectal. Material y método: Estudio longitudinal de base de datos prospectiva de pacientes operados por cirugía colorrectal entre julio de 2007 y agosto de 2014. Resultados: De un total de 654 pacientes operados, 52,3% correspondían a hombres con una edad promedio de 57 años (42-72). La indicación más frecuente fue cáncer colorrectal con 244 pacientes, 159 (24,3%) operados por cáncer de colon y 85 (12,9%) por cáncer de recto, seguido por la enfermedad diverticular con 239 pacientes (36,5%) y 171 pacientes (26,1%) con otros diagnósticos. En 44 pacientes (6,7%) se objetivó filtración anastomótica, con una mediana de 4 días desde el postoperatorio para su diagnóstico. Como factores asociados a filtración se identificó al género masculino, riesgo anestesiológico según ASA, necesidad de conversión a laparotomía y la anastomosis ileoanal. En relación con el tratamiento, 15 pacientes (33,7%) fueron tratados de forma médica exitosa y 29 fue necesario reintervenirlos, de los cuales 23 (79,3%) requirieron una ostomía de protección. No hubo mortalidad asociada a la cirugía, y el promedio de hospitalización en los pacientes con filtración fue de 12 vs. 5 días para los pacientes sin filtración de la anastomosis. Conclusión: Este trabajo permite identificar a grupos de pacientes con mayor riesgo de filtraciones anastomóticas, quienes duplican su estadía hospitalaria y en un alto porcentaje deben ser reintervenidos. La sospecha y diagnostico precoz reducen la morbimortalidad.

Introduction: Anastomotic leak is the most important complication on colorectal surgery. Objective: Analyze the frequency and impact of anastomotic leaks in laparoscopic colorectal surgery. Material and methods: Longitudinal study of prospective database of patients undergoing colorectal surgery between July 2007 and August 2014. Results: 654 patients operated, 52.3% were men with an average age of 57 years (42-72). The most frequent indication was colorectal cancer in 244 patients, 159 (24.3%) operated for colon cancer and 85 (12.9%) for rectal cancer followed by diverticular disease in 239 patients (36.5%) and 171 patients (26.1%) with other diagnoses. In 44 patients (6.7%) anastomotic leakage was observed with a median of 4 days post surgery for diagnosis. As factors associated with filtration, we identified male gender, anesthesic risk according to ASA, need for conversion to laparotomy and ileoanal anastomosis. With regard to treatment, 15 (33.7%) were successfully treated with medical therapy alone and 29 required re-intervention, of which 23 (79.3%) required an ostomy protection. There was no mortality associated with surgery and average LOS was 12 vs. 5 days in patients with filtration compared with patients without anastomotic leakeage. Conclusion: This serie helps to identify patients groups with increased risk of anastomotic leakage who double their hospital LOS and in a higher percentage should need re-intervention. Suspicion and early diagnosis reduces morbidity and mortality.

Tuberculosis ileocecal: revisión de la literatura a partir de un caso clínico / Ileocecal tuberculosis: literature review from a case report

Tuberculosis (TB) remains a major public health challenge. The true incidence of intestinal TB is unknown, as it can be asymptomatic, and by its nature, often diverts its diagnosis to neoplastic diseases or inflammatory bowel disease. Therefore, we must have a high index of suspicion, not only in high risk populations and immunocompromised patients. Diagnostic tests that certify the pathology, don’t always achieve excellent performance. Endoscopic findings are not always clear in differentiating malignancy, and in some cases, a therapeutic trial may be needed to confirm the disease. We present the case of a patient with chronic diarrhea, consumptive syndrome and without respiratory symptoms at its onset.

La tuberculosis (TBC) sigue siendo un reto importante de salud pública. La verdadera incidencia de TBC intestinal es desconocida, ya que puede ser asintomática, y por su naturaleza a menudo desvía su diagnóstico a patologías neoplásicas o de enfermedad inflamatoria intestinal. Por lo tanto, se debe tener un alto índice de sospecha, no sólo en poblaciones de alto riesgo y en pacientes inmunocomprometidos. Las pruebas diagnósticas que certifiquen la patología no siempre se logran ni tienen un excelente rendimiento. Los hallazgos endoscópicos no siempre son claros para diferenciarla de una neoplasia, y en algunos casos una prueba terapéutica puede ser la confirmación de la enfermedad. Presentamos el caso de un paciente con diarrea crónica, cuadro consuntivo y sin síntomas respiratorios al inicio de su cuadro.

Antisense-mediated therapeutic pseudoexon skipping in TMEM165-CDG.

Deficiencies in glycosyltransferases, glycosidases or nucleotide-sugar transporters involved in protein glycosylation lead to congenital disorders of glycosylation (CDG), a group of genetic diseases mostly showing multisystem phenotype. Despite recent advances in the biochemical and molecular knowledge of these diseases, no effective therapy exists for most. Efforts are now being directed toward therapies based on identifying new targets, which would allow to treat specific patients in a personalized way. This work presents proof-of concept for the antisense RNA rescue of the Golgi-resident protein TMEM165, a gene involved in a new type of CDG with a characteristic skeletal phenotype. Using a functional in vitro splicing assay based on minigenes, it was found that the deep intronic change c.792+182G>A is responsible for the insertion of an aberrant exon, corresponding to an intronic sequence. Antisense morpholino oligonucleotide therapy targeted toward TMEM165 mRNA recovered normal protein levels in the Golgi apparatus of patient-derived fibroblasts. This work expands the application of antisense oligonucleotide-mediated pseudoexon skipping to the treatment of a Golgi-resident protein, and opens up a promising treatment option for this specific TMEM165-CDG.

Thirteen years experience with selective screening for disorders in purine and pyrimidine metabolism.

Purine and pyrimidine disorders represent a heterogeneous group with variable clinical symptoms and low prevalence rate. In the last thirteen years, we have studied urine/plasma specimens from about 1600 patients and we have identified 35 patients: eight patients with adenylosuccinate lyase deficiency, eight patients with hypoxanthine-guanine phosphoribosyltransferase deficiency, one patient with purine nucleoside phosphorylase deficiency, ten patients with xanthine dehydrogenase deficiency, six patients with molybdenum cofactor deficiency and two patients with dihydropyrimidine dehydrogenase deficiency. Despite low incidence of these diseases, our findings highlight the importance of including the purine and pyrimidine analysis in the selective screening for inborn errors of metabolism in specialized laboratories, where amino acid and organic acid disorders are simultaneously investigated.

Deficiencia de holocarboxilasa sintetasa de presentación tardía con actividad piruvato carboxilasa normal / Delayed onset holocarboxylase synthetase deficiency with normal pyruvate carboxylase activity

Se presenta un caso de deficiencia de holocarboxilasa sintetasa con actividad piruvato carboxilasa normal en linfocitos en una niña de 8 años con clínica de intoxicación y sin la clásica afectación dermatológica. La identificación de 3 cambios nucleotídicos en el gen HCLS, habiendo sido descrito como mutación patogénica solo uno de ellos, podría estar relacionada con una variante leve de la enfermedad que explicaría la presentación inusual más allá de la época de lactante. El tratamiento con biotina a 40 mg/día, junto con dieta controlada en proteínas, permite un crecimiento físico y un desarrollo psicomotor normales para su edad

We report a case of holocarboxylase synthetase deficiency with normal pyruvate carboxylase activity in the lymphocytes of an 8 year-old girl with clinical toxicity without the classic dermatological involvement. The identification of three nucleotide changes in the holocarboxylase synthetase (HLCS) gene, only one of them described as a pathogenic mutation could be related to a slight variant of the disease that would explain the unusual presentation beyond the age of infant. Treatment with biotin at 40 mg/day with protein controlled diet allows normal physical growth and psychomotor development for their age

Functional analysis and in vitro correction of splicing FAH mutations causing tyrosinemia type I.

Hereditary tyrosinemia type I (HT1) is a rare disease caused by a deficiency of fumarylacetoacetate hydrolase (FAH) in the tyrosine catabolic pathway, resulting mainly in hepatic alterations due to accumulation of the toxic metabolites fumarylacetoacetate, maleylacetoacetate and succinylacetone. We have characterized using minigenes four splicing mutations affecting exonic or intronic nucleotides of the FAH gene identified in two HT1 patients. Two of the mutations are novel, c.82-1G>A and c.913G>C and the other two have been previously associated with a splicing defect (c.836A>G and c.1062+5G>A). All mutations were confirmed to affect splicing in minigenes, resulting in exon skipping or activation of a cryptic splice site. We have analyzed the effect of different compounds known to modulate splicing (valproic acid, phenyl butyrate, M344, EIPA, and resveratrol) and the overexpression of splice factors of the SR protein family on the transcriptional profile of the mutant minigenes. For the c.836A>G mutation, a partial recovery of the correctly spliced transcript was observed. These results confirm the relevance of performing functional studies for mutations potentially affecting the splicing process and open the possibility of supplementary therapeutic approaches to diseases caused by splicing defects.