[Argentinean Consensus on the Diagnosis and Treatment of Niemann- Pick Disease Type C]. / Consenso argentino sobre diagnóstico y tratamiento de la enfermedad de Niemann-Pick Tipo C.

Niemann-Pick type C (NPC) is a disorder of the lysosomal metabolism due to biallelic pathogenic variants in NPC1 or NPC2. Intracellular deposit of lipids, mainly unesterified cholesterol, gives rise to oxidative damage in several tissues, mainly neurons, spleen and liver. This, in turn, is associated with a myriad of neurological / psychiatric and visceral symptoms, with wide variability in age of presentation, from prenatal / neonatal to adult-onset forms of the disease. The last few years have seen considerable progress in understanding this disease and its management. In this consensus, current approaches to the diagnosis, follow-up and treatment of NPC (including the use of miglustat, the only specific drug approved at the time) are discussed by an Argentinian panel of experts.

La enfermedad de Niemann-Pick tipo C (NPC) es un trastorno del metabolismo lisosomal que se debe a la presencia de variantes patogénicas bialélicas en los genes NPC1 o NPC2. El depósito intracelular de lípidos, especialmente colesterol no esterificado, provoca daño oxidativo en diversos tejidos, especialmente neuronas, bazo e hígado. Esto, a su vez, induce la aparición de un conjunto de síntomas neurológicos / psiquiátricos y viscerales, con una amplia variabilidad de edad de aparición, desde formas prenatales / neonatales hasta otras de aparición en la vida adulta. En los últimos años ha habido avances considerables en la comprensión sobre esta enfermedad y su manejo. En el presente consenso un grupo de expertos argentinos abordan los enfoques actuales de diagnóstico, seguimiento y tratamiento de NPC, incluyendo el uso de miglustat como única terapia específica aprobada en la actualidad.

Consenso Argentino sobre Diagnóstico y Tratamiento de la Enfermedad de Niemann-Pick tipo C / Argentinean Consensus on the Diagnosis and Treatment of Niemann-Pick Disease type C

Resumen La enfermedad de Niemann-Pick tipo C (NPC) es un trastorno del metabolismo lisosomal que se debe a la presencia de variantes patogénicas bialélicas en los genes NPC1 o NPC2. El depósito intracelular de lípidos, especialmente colesterol no esterificado, provoca daño oxidativo en diversos tejidos, especialmente neuronas, bazo e hígado. Esto, a su vez, induce la aparición de un conjunto de síntomas neurológicos/psiquiátricos y viscerales, con una amplia variabilidad de edad de apa rición, desde formas prenatales/neonatales hasta otras de aparición en la vida adulta. En los últimos años ha habido avances considerables en la comprensión sobre esta enfermedad y su manejo. En el presente consenso un grupo de expertos argentinos abordan los enfoques actuales de diagnóstico, seguimiento y tratamiento de NPC, incluyendo el uso de miglustat como única terapia específica aprobada en la actualidad.

Abstract Niemann-Pick type C (NPC) is a disorder of the lyso somal metabolism due to biallelic pathogenic variants in NPC1 or NPC2. Intracellular deposit of lipids, mainly unesterified cholesterol, gives rise to oxidative damage in several tissues, mainly neurons, spleen and liver. This, in turn, is associated with a myriad of neurologi cal/psychiatric and visceral symptoms, with wide vari ability in age of presentation, from prenatal/neonatal to adult-onset forms of the disease. The last few years have seen considerable progress in understanding this disease and its management. In this consensus, current approaches to the diagnosis, follow-up and treatment of NPC (including the use of miglustat, the only specific drug approved at the time) are discussed by an Argentin ian panel of experts.

Manejo inicial de la hiperamonemia aguda en pediatría / Initial management of acute hyperammonemia in pediatrics

La hiperamonemia constituye una emergencia médica. No existen publicaciones que hagan referencia a la disponibilidad de recursos, insumos y conocimientos necesarios para el manejo inicial de esta por parte del pediatra en nuestro país, pero, según la experiencia de los autores, los recursos necesarios no se encuentran disponibles los 365 días del año en una gran porción de nuestro territorio. Sobre la base de este estado de situación, de una revisión bibliográfica internacional sobre el tema y de la experiencia de los autores, se elaboraron una serie de recomendaciones para el manejo pediátrico inicial de esta emergencia, que tienen como objetivo poder reducir las deficiencias, permitir una sospecha clínica adecuada que lleve a un diagnóstico y tratamiento de emergencia oportunos, con utilización racional de recursos farmacológicos (algunos de ellos de alto costo), para reducir la morbimortalidad que asocia la patología.

Hyperammonemia is a medical emergency. There are no publications regarding the availability of resources, supplies, and knowledge necessary for the initial management of hyperammonemia by pediatricians in Argentina; however, according to the authors' experience, the necessary resources are not available all year round in a large portion of our territory. Based on such state of affairs, an international bibliographic review on this topic and the authors' experience, we developed a series of recommendations for the initial pediatric management of this emergency, with the objective of reducing deficiencies, allowing adequate clinical suspicion leading to a timely diagnosis and emergency management and a rational use of pharmacological resources (some of which are costly) to reduce the morbidity and mortality associated with hyperammonemia.

Initial management of acute hyperammonemia in pediatrics. / Manejo inicial de la hiperamonemia aguda en pediatría.

Hyperammonemia is a medical emergency. There are no publications regarding the availability of resources, supplies, and knowledge necessary for the initial management of hyperammonemia by pediatricians in Argentina; however, according to the authors' experience, the necessary resources are not available all year round in a large portion of our territory. Based on such state of affairs, an international bibliographic review on this topic and the authors' experience, we developed a series of ecommendations for the initial pediatric management of this emergency, with the objective of reducing deficiencies, allowing adequate clinical suspicion leading to a timely diagnosis and emergency management and a rational use of pharmacological resources (some of which are costly) to reduce the morbidity and mortality associated with hyperammonemia.

La hiperamonemia constituye una emergencia médica. No existen publicaciones que hagan referencia a la disponibilidad de recursos, insumos y conocimientos necesarios para el manejo inicial de esta por parte del pediatra en nuestro país, pero, según la experiencia de los autores, los recursos necesarios no se encuentran disponibles los 365 días del año en una gran porción de nuestro territorio. Sobre la base de este estado de situación, de una revisión bibliográfica internacional sobre el tema y de la experiencia de los autores, se elaboraron una serie de recomendaciones para el manejo pediátrico inicial de esta emergencia, que tienen como objetivo poder reducir las deficiencias, permitir una sospecha clínica adecuada que lleve a un diagnóstico y tratamiento de emergencia oportunos, con utilización racional de recursos farmacológicos (algunos de ellos de alto costo), para reducir la morbimortalidad que asocia la patología.

Enfoque práctico en el diagnóstico de los errores congénitos del metabolismo / Practical approach to the diagnosis of inherited metabolic diseases

Resumen Los errores congénitos del metabolismo constituyen un grupo creciente de enfermedades poco frecuentes con habitual impacto neurológico. Heterogéneas en el aspecto clínico y bioquímico, su diagnóstico y terapéutica son dificultosos. Los avances en su conocimiento, en los métodos diagnósticos y en sus tratamientos, ponen de relevancia lo importante de un diagnóstico oportuno, puerta del acceso a la inter vención médica temprana. Es muy relevante la sospecha del neuropediatra ante diferentes situaciones clínicas. El presente artículo pretende ser un aporte práctico para facilitar su reconocimiento.

Abstract Inborn errors of metabolism constitute a growing group of rare diseases with usual neurological impact. Hete-rogeneous in clinical and biochemical aspects, its diagnosis and treatment are difficult. Advances in its knowledge, in diagnostic methods and in its treatments, highlight the importance of a timely diagnosis, the gateway to access to early medical intervention. The neuropediatrician's suspicion in different clini cal situations is very relevant. This article aims to be a practical contribution to facilitate their recognition.

[Practical approach to the diagnosis of inherited metabolic diseases]. / Enfoque práctico en el diagnóstico de los errores congénitos del metabolismo.

Inborn errors of metabolism constitute a growing group of rare diseases with usual neurological impact. Heterogeneous in clinical and biochemical aspects, its diagnosis and treatment are difficult. Advances in its knowledge, in diagnostic methods and in its treatments, highlight the importance of a timely diagnosis, the gateway to access to early medical intervention. The neuropediatrician's suspicion in different clinical situations is very relevant. This article aims to be a practical contribution to facilitate their recognition.

Los errores congénitos del metabolismo constituyen un grupo creciente de enfermedades poco frecuentes con habitual impacto neurológico. Heterogéneas en el aspecto clínico y bioquímico, su diagnóstico y terapéutica son dificultosos. Los avances en su conocimiento, en los métodos diagnósticos y en sus tratamientos, ponen de relevancia lo importante de un diagnóstico oportuno, puerta del acceso a la intervención médica temprana. Es muy relevante la sospecha del neuropediatra ante diferentes situaciones clínicas. El presente artículo pretende ser un aporte práctico para facilitar su reconocimiento.

Síndrome de osteoporosis-pseudoglioma: a propósito de un caso pediátrico de osteoporosis primaria / Osteoporosis-pseudoglioma Syndrome: a pediatric case of primary osteoporosis

La osteoporosis es un trastorno para tener en cuenta en niños con patologías crónicas graves o con algunas enfermedades genéticas que predisponen al incremento de la fragilidad ósea. La osteoporosis primaria es una entidad con etiologías emergentes y puede ocurrir en forma sindrómica. La asociación con pliegues retinianos congénitos debe orientar al diagnóstico de osteoporosis-pseudoglioma (OMIM 259770), síndrome poco frecuente (prevalencia de 1/2000000), que se origina por la pérdida de función de la proteína LRP5 (low-density lipoprotein receptor-related protein 5) y compromete la vía de señalización de Wnt/ß-catenina. Se presenta el caso de un niño con pliegues retinianos congénitos, ceguera progresiva y múltiples fracturas cuyo estudio clínico, bioquímico y genético confirmó el diagnóstico de osteoporosis primaria debido a una nueva variante inactivante en el gen LRP5 en homocigosis

Osteoporosis should be considered in children with severe chronic diseases or in association with some genetic diseases that bear an increased risk of bone fragility. Primary osteoporosis is an entity in which emerging aetiologies are being recognized. Its association with congenital retinal folds should guide the diagnosis to the Osteoporosis-Pseudoglioma syndrome (OMIM 259770), a rare disease (prevalence of 1/2000000), caused by the loss of function of the protein LRP5 (low-density lipoprotein receptor-related protein 5) resulting in the alteration of the Wnt/ß-catenin signalling pathway. We report the case of a child with congenital retinal folds, progressive loss of vision and multiple fractures whose clinical, biochemical and genetic studies confirmed the diagnosis of primary osteoporosis due to a novel homozygous inactivating variant in LRP5

[Osteoporosis-pseudoglioma Syndrome: a pediatric case of primary osteoporosis]. / Síndrome de osteoporosis-pseudoglioma: a propósito de un caso pediátrico de osteoporosis primaria.

Osteoporosis should be considered in children with severe chronic diseases or in association with some genetic diseases that bear an increased risk of bone fragility. Primary osteoporosis is an entity in which emerging aetiologies are being recognized. Its association with congenital retinal folds should guide the diagnosis to the Osteoporosis-Pseudoglioma syndrome (OMIM 259770), a rare disease (prevalence of 1/2 000 000), caused by the loss of function of the protein LRP5 (low-density lipoprotein receptor-related protein 5) resulting in the alteration of the Wnt/ß-catenin signalling pathway. We report the case of a child with congenital retinal folds, progressive loss of vision and multiple fractures whose clinical, biochemical and genetic studies confirmed the diagnosis of primary osteoporosis due to a novel homozygous inactivating variant in LRP5.

La osteoporosis es un trastorno para tener en cuenta en niños con patologías crónicas graves o con algunas enfermedades genéticas que predisponen al incremento de la fragilidad ósea. La osteoporosis primaria es una entidad con etiologías emergentes y puede ocurrir en forma sindrómica. La asociación con pliegues retinianos congénitos debe orientar al diagnóstico de osteoporosis-pseudoglioma (OMIM 259770), síndrome poco frecuente (prevalencia de 1/2 000 000), que se origina por la pérdida de función de la proteína LRP5 (low-density lipoprotein receptor-related protein 5) y compromete la vía de señalización de Wnt/ß-catenina. Se presenta el caso de un niño con pliegues retinianos congénitos, ceguera progresiva y múltiples fracturas cuyo estudio clínico, bioquímico y genético confirmó el diagnóstico de osteoporosis primaria debido a una nueva variante inactivante en el gen LRP5 en homocigosis.

Skeletal involvement in Gaucher disease: An observational multicenter study of prognostic factors in the Argentine Gaucher disease patients.

Patients with Gaucher type 1 (GD1) throughout Argentina were enrolled in the Argentine bone project to evaluate bone disease and its determinants. We focused on presence and predictors of bone lesions (BL) and their relationship to therapeutic goals (TG) with timing and dose of enzyme replacement therapy (ERT). A total of 124 patients on ERT were enrolled in a multi-center study. All six TG were achieved by 82% of patients: 70.1% for bone pain and 91.1% for bone crisis. However, despite the fact that bone TGs were achieved, residual bone disease was present in 108 patients on ERT (87%) at time 0. 16% of patients showed new irreversible BL (bone infarcts and avascular osteonecrosis) despite ERT, suggesting that they appeared during ERT or were not detected at the moment of diagnosis. We observed 5 prognostic factors that predicted a higher probability of being free of bone disease: optimal ERT compliance; early diagnosis; timely initiation of therapy; ERT initiation dose ≥45 UI/kg/EOW; and the absence of history of splenectomy. Skeletal involvement was classified into 4 major phenotypic groups according to BL: group 1 (12.9%) without BL; group 2 (28.2%) with reversible BL; group 3 (41.9%) with reversible BL and irreversible chronic BL; and group 4 (16.9%) with acute irreversible BL. Our study identifies prognostic factors for achieving best therapeutic outcomes, introduces new risk stratification for patients and suggests the need for a redefinition of bone TG. Am. J. Hematol. 91:E448-E453, 2016. © 2016 Wiley Periodicals, Inc.

Clinical course of sly syndrome (mucopolysaccharidosis type VII).

BACKGROUND: Mucopolysaccharidosis VII (MPS VII) is an ultra-rare disease characterised by the deficiency of ß-glucuronidase (GUS). Patients' phenotypes vary from severe forms with hydrops fetalis, skeletal dysplasia and mental retardation to milder forms with fewer manifestations and mild skeletal abnormalities. Accurate assessments on the frequency and clinical characteristics of the disease have been scarce. The aim of this study was to collect such data. METHODS: We have conducted a survey of physicians to document the medical history of patients with MPS VII. The survey included anonymous information on patient demographics, family history, mode of diagnosis, age of onset, signs and symptoms, severity, management, clinical features and natural progression of the disease. RESULTS: We collected information on 56 patients from 11 countries. Patients with MPS VII were classified based on their phenotype into three different groups: (1) neonatal non-immune hydrops fetalis (NIHF) (n=10), (2) Infantile or adolescent form with history of hydrops fetalis (n=13) and (3) Infantile or adolescent form without known hydrops fetalis (n=33). Thirteen patients with MPS VII who had the infantile form with history of hydrops fetalis and survived childhood, had a wide range of clinical manifestations from mild to severe. Five patients underwent bone marrow transplantation and one patient underwent enzyme replacement therapy with recombinant human GUS. CONCLUSIONS: MPS VII is a pan-ethnic inherited lysosomal storage disease with considerable phenotypical heterogeneity. Most patients have short stature, skeletal dysplasia, hepatosplenomegaly, hernias, cardiac involvement, pulmonary insufficiency and cognitive impairment. In these respects it resembles MPS I and MPS II. In MPS VII, however, one unique and distinguishing clinical feature is the unexpectedly high proportion of patients (41%) that had a history of NIHF. Presence of NIHF does not, by itself, predict the eventual severity of the clinical course, if the patient survives infancy.

[Morquio disease (Mucopolysaccharidosis type IV-A): clinical aspects, diagnosis and new treatment with enzyme replacement therapy]. / Enfermedad de Morquio (mucopolisacaridosis IV-A): aspectos clínicos, diagnósticos y nuevo tratamiento con terapia de reemplazo enzimático.

Mucopolysaccharidosis type IV-A (Morquio A disease) is an autosomal recessive lysosomal storage disease caused by mutations in the gene encoding the N-acetylgalactosamine-6-sulfate sulfatase, that results in impaired catabolism of two glycosaminoglycans, chondroitin-6-sulfate and keratan sulfate. Clinical presentations reflect a spectrum of progression from a severe phenotype to an attenuated expression. Accumulation of substrate manifests predominantly as short stature and skeletal dysplasia, including atlantoaxial instability and cervical cord compression. Other abnormalities in the visual, auditory, cardiovascular and respiratory systems can also affect individuals with Morquio disease. Elosulfase alfa showed in clinical trials in children and adults a significant and sustained improvement in endurance and urinary levels of keratan sulfate. Data from the ongoing observational, multinational Morquio A Registry Study will provide valuable information on the long-term efficacy and safety of elosulfase alfa in patients, as well as on the natural history of this very rare disease.

Mucopolisacaridosis VI: aspectos clínicos, iagnósticos y del tratamiento con terapia de eemplazo enzimático / Mucopolysaccharidosis type VI: clinical aspects, diagnosis and treatment with enzyme replacement therapy

La mucopolisacaridosis de tipo VI (MPS VI) es una enfermedad de almacenamiento lisosomal resultante del déficit o ausencia de la arilsulfatasa B, que conduce a una acumulación patológica de dermatán-sulfato. Presenta un amplio espectro de síntomas, que van desde formas lentas hasta rápidamente progresivas. Los síntomas característicos son el compromiso esquelético, facies tosca, cardiopatía y compresión medular cervical. El diagnóstico se realiza por la determinación de glucosaminoglucanos en la orina y de la actividad enzimática en una gota de sangre seca, leucocitos o cultivo de fibroblastos. Actualmente, la terapia de reemplazo enzimático (TRE) con galsulfasa ha mostrado mejorar el compromiso esquelético y estabilizar la función respiratoria y cardíaca. El compromiso medular no suele responder a la TRE cuando ya se encuentra presente, por lo que la descompresión quirúrgica debe indicarse en forma temprana. El pronóstico varía en función del fenotipo y de la edad de inicio del tratamiento

Mucopolysaccharidosis VI (MPS VI) is a lysosomal storage disease associated with a deficiency or absence of arylsulfatase B leading to the abnormal accumulation of dermatan sulfate. MPS VI shows a wide spectrum of symptoms from slowly to rapidly progressing forms. The characteristic spectrum includes skeletal displasia, coarse facies, cardiomyopathy, pulmonary complications and spinal compression. Diagnosis generally requires measurement ofurinary glycosaminoglycans and arylsulfatase B enzyme activity in dried blood spot, leukocytes or cultured fibroblasts. Enzyme replacement therapy (ERT) with galsulfase is now widely available providing improvement in skeletal performance and stabilization in pulmonary and cardiac functioning. Spinal involvement does not respond to ERT when is present, surgical decompression should be indicated early. Prognosis is variable depending on the age of onset and age at initiation of ERT.

[Mucopolysaccharidosis type VI: clinical aspects, diagnosis and treatment with enzyme replacement therapy]. / Mucopolisacaridosis VI: aspectos clínicos, iagnósticos y del tratamiento con terapia de eemplazo enzimático.

Mucopolysaccharidosis VI (MPS VI) is a lysosomal storage disease associated with a deficiency or absence of arylsulfatase B leading to the abnormal accumulation of dermatan sulfate. MPS VI shows a wide spectrum of symptoms from slowly to rapidly progressing forms. The characteristic spectrum includes skeletal displasia, coarse facies, cardiomyopathy, pulmonary complications and spinal compression. Diagnosis generally requires measurement ofurinary glycosaminoglycans and arylsulfatase B enzyme activity in dried blood spot, leukocytes or cultured fibroblasts. Enzyme replacement therapy (ERT) with galsulfase is now widely available providing improvement in skeletal performance and stabilization in pulmonary and cardiac functioning. Spinal involvement does not respond to ERT when is present, surgical decompression should be indicated early. Prognosis is variable depending on the age of onset and age at initiation of ERT.

Enfermedad de Fabry: la importancia de la terapia de reemplazo enzimático (TRE): tratar rápida y eficazmente / Fabry Disease: the importance of the, enzyme replacement therapy (TRE): treating quickly and efficiently

La enfermedad de Fabry en un trastorno lisosomal por ausencia o deficiencia de la enzima Alfa galactosidasa A que genera un acúmulo patológico de glicoesfingolípidos principalmente en células endoteliales, musculares lisas de vasos sanguíneos y podocitos entre otras. La terapia de reemplazo enzimático es la única chance de tratamiento específico a la fecha. El creciente conocimiento de los mecanismos fisiopatológicos ha llevado a cambiar el manejo de la enfermedad y por sobretodo el momento de inicio del tratamiento. Actualmente el inicio en edades más tempranas parece ser una forma de evitar y en algunos casos revertir algunos de los signos y síntomas de la enfermedad de Fabry.

Fabry Disease is a lysosomal disorder due to the absence or deficiency of the Alpha galactosidase A enzyme that causes a pathological ac cumulation of glycosphingolipids mainly in the REVISIÓN endothelial cells, vascular smooth muscle cells and podocytes among others. Enzyme replacement therapy is the only option for a specific treatment at present. Increasing knowledge of the physiopathological mechanisms has changed the management of the disease and above all, when treatment should begin. At present, beginning treatment at an early age seems to be a way of preventing and in some cases reverting some of the signs and symptoms of Fabry disease.

Vertebrobasilar Dolichoectasia in Fabry Disease: The Earliest Marker of Neurovascular Involvement?

Abstract Introduction: Fabry disease (FD) is a lysosomal storage disorder associated with marked cerebrovascular involvement. Conventional magnetic resonance imaging (MRI) shows different abnormalities, like white matter lesions that may already be present at an early stage in the disease. Aim: To present observations from a series of brain MRIs performed among a cohort of patients with FD and the relationship of imaging abnormalities with the presence of cardiovascular risk factors (CVRFs). Methods: A total of 70 patients with FD (43 women) were enrolled. The cardiac, renal, ophthalmic, and peripheral nerve functioning was assessed. The MRI evaluation included assessment for evidence of ischemia, microbleeds, pulvinar sign, Arnold-Chiari type 1 malformation, and vertebrobasilar dolichoectasia (VBD). The presence or absence of CVRFs was examined for all patients. Results: Renal involvement was found in 60%, cardiac compromise in 30%, cornea verticillata in 91.4%, and acroparesthesias in 87.1% of patients. Brain MRI analysis found evidence of cerebral ischemic injury in 25.9% of men and 30.2% of women. Vertebrobasilar dolichoectasia was observed in imaging from 55.5% of men and 34.8% of women. The logistic regression analysis adjusted for cardiovascular risks factors, using ischemia or VBD as a dependent variable, showed no statistically significant results. Discussion: Our results have demonstrated cerebrovascular involvement before the third decade in many patients with FD. This study is further evidence confirming that women are not just carriers of FD and should be followed clinically and evaluated comprehensively to monitor for disease burden and progression. Although silent brain ischemias in MRI should be included as a key feature for the diagnoses of FD, VBD is an earlier and frequent sign.

[Long chain 3-hydroxyacyl-coA dehydrogenase deficiency, association with HELLP and magnetic resonance spectroscopy findings]. / Deficiencia de 3-hidroxiacil coA deshidrogenasa de cadena larga, asociación con HELLP y hallazgos en la espectroscopia por resonancia magnética.

LCHAD deficiency is a disorder of fatty acid beta oxidation. The most common clinical presentation includes disorders of consciousness, hypoglycemia and liver dysfunction triggered by prolonged fasting or infection. Once a metabolic crisis is triggered, there is a high mortality. HELLP syndrome and acute fatty liver failure of pregnancy (AFLP) are disorders of the third trimester of pregnancy. These diseases have been associated during pregnancy with hereditary defects of beta-oxidation in the fetus. We report a case of beta-oxidation disorder (LCHAD deficiency) associated with maternal HELLP. We described a peak of lipid and lactic on magnetic resonance spectroscopic of this patient. The investigation of these beta-oxidation disorders at birth, with a history of maternal HELLP, allows the diagnosis of the disease prior to developing symptoms.

Deficiencia de 3-hidroxiacil coA deshidrogenasa de cadena larga, asociación con HELLP y hallazgos en la espectroscopia por resonancia magnética / Long chain 3-hydroxyacyl-coA dehydrogenase deficiency, asociation with HELLP and magnetic resonance spectroscopy findings

La deficiencia de 3-hidroxiacil coA deshidrogenasa de cadena larga (LCHAD) es uno de los trastornos de la betaoxidación de ácidos grasos. La presentación clínica más frecuente incluye trastornos de conciencia, hipoglucemia y disfunción hepática gatillados por ayuno prolongado o infecciones. Una vez desencadenada, la crisis metabólica presenta alta mortalidad. El síndrome HELLP y la hepatitis grasa aguda del embarazo (AFLP) son trastornos del tercer trimestre del embarazo. Se ha asociado estas enfermedades durante la gestación con defectos hereditarios de la betaoxidación en el feto. Comunicamos el caso clínico de un trastorno de beta oxidación (deficiencia de LCHAD) asociado a HELLP materno. Describimos como hallazgos en la resonancia magnética espectroscópica un pico de ácido láctico y lípidos significativo. La pesquisa de estos trastornos de la betaoxidación al nacimiento, ante el antecedente de HELLP materno, permite el diagnóstico de la enfermedad previo al desarrollo de los síntomas.

LCHAD deficiency is a disorder of fatty acid beta oxidation. The most common clinical presentation includes disorders of consciousness, hypoglycemia and liver dysfunction triggered by prolonged fasting or infection. Once a metabolic crisis is triggered, there is a high mortality. HELLP syndrome and acute fatty liver failure of pregnancy (AFLP) are disorders of the third trimester of pregnancy. These diseases have been associated during pregnancy with hereditary defects of beta-oxidation in the fetus. We report a case of beta-oxidation disorder (LCHAD deficiency) associated with maternal HELLP. We described a peak of lipid and lactic on magnetic resonance spectroscopic of this patient. The investigation of these beta-oxidation disorders at birth, with a history of maternal HELLP, allows the diagnosis of the disease prior to developing symptoms.

Molecular analysis of HEXA gene in Argentinean patients affected with Tay-Sachs disease: possible common origin of the prevalent c.459+5A>G mutation.

Tay-Sachs disease (TSD) is a recessively inherited disorder caused by the deficient activity of hexosaminidase A due to mutations in the HEXA gene. Up to date there is no information regarding the molecular genetics of TSD in Argentinean patients. In the present study we have studied 17 Argentinean families affected by TSD, including 20 patients with the acute infantile form and 3 with the sub-acute form. Overall, we identified 14 different mutations accounting for 100% of the studied alleles. Eight mutations were novel: 5 were single base changes leading to drastic residue changes or truncated proteins, 2 were small deletions and one was an intronic mutation that may cause a splicing defect. Although the spectrum of mutations was highly heterogeneous, a high frequency of the c.459+5G>A mutation, previously described in different populations was found among the studied cohort. Haplotype analysis suggested that in these families the c.459+5G>A mutation might have arisen by a single mutational event.

Molecular characterization of 22 novel UDP-N-acetylglucosamine-1-phosphate transferase alpha- and beta-subunit (GNPTAB) gene mutations causing mucolipidosis types IIalpha/beta and IIIalpha/beta in 46 patients.

Mutational analysis of the GNPTAB gene was performed in 46 apparently unrelated patients with mucolipidosis IIalpha/beta or IIIalpha/beta, characterized by the mistargeting of multiple lysosomal enzymes as a consequence of a UDP-GlcNAc-1-phosphotransferase defect. The GNPTAB mutational spectrum comprised 25 distinct mutant alleles, 22 of which were novel, including 3 nonsense mutations (p.Q314X, p.R375X, p.Q507X), 5 missense mutations (p.I403T, p.C442Y, p.C461G, p.Q926P, p.L1001P), 6 microduplications (c.749dupA, c.857dupA, c.1191_1194dupGCTG, c.1206dupT, c.1331dupG, c.2220_2221dupGA) and 8 microdeletions (c.755_759delCCTCT, c.1399delG, c.1959_1962delTAGT, c.1965delC, c.2550_2554delGAAAA, c.3443_3446delTTTG, c.3487_3490delACAG, c.3523_3529delATGTTCC). All micro-duplications/deletions were predicted to result in the premature termination of translation. A novel exonic SNP (c.303G>A; E101E) was identified which is predicted to create an SFRS1 (SF2/ASF) binding site that may be of potential functional/clinical relevance. This study of mutations in the GNPTAB gene, the largest yet reported, extends our knowledge of the mutational heterogeneity evident in MLIIalpha/beta/MLIIIalpha/beta.