Two compound heterozygous variants in the CLN8 gene are responsible for neuronal cereidolipofuscinoses disorder in a child: a case report.

Background: Neuronal Ceroid Lipofuscinosis (NCL) disorders, recognized as the primary cause of childhood dementia globally, constitute a spectrum of genetic abnormalities. CLN8, a subtype within NCL, is characterized by cognitive decline, motor impairment, and visual deterioration. This study focuses on an atypical case with congenital onset and a remarkably slow disease progression. Methods: Whole-genome sequencing at 30× coverage was employed as part of a national genomics program to investigate the genetic underpinnings of rare diseases. This genomic approach aimed to challenge established classifications (vLINCL and EPMR) and explore the presence of a continuous phenotypic spectrum associated with CLN8. Results: The whole-genome sequencing revealed two novel likely pathogenic mutations in the CLN8 gene on chromosome 8p23.3. These mutations were not previously associated with CLN8-related NCL. Contrary to established classifications (vLINCL and EPMR), our findings suggest a continuous phenotypic spectrum associated with CLN8. Pathological subcellular markers further validated the genomic insights. Discussion: The identification of two previously undescribed likely pathogenic CLN8 gene mutations challenges traditional classifications and highlights a more nuanced phenotypic spectrum associated with CLN8. Our findings underscore the significance of genetic modifiers and interactions with unrelated genes in shaping variable phenotypic outcomes. The inclusion of pathological subcellular markers further strengthens the validity of our genomic insights. This research enhances our understanding of CLN8 disorders, emphasizing the need for comprehensive genomic analyses to elucidate the complexity of phenotypic presentations and guide tailored therapeutic strategies. The identification of new likely pathogenic mutations underscores the dynamic nature of CLN8-related NCL and the importance of individualized approaches to patient management.

Fibrodysplasia ossificans progressiva in a 3-year-old female patient.

BACKGROUND: Fibrodysplasia ossificans progressiva (FOP) is a rare autosomal dominant disease affecting connective tissue, primarily caused by de novo mutations of the ACVR1 gene. FOP is a disease with congenital malformations of the toes and heterotopic ossification in characteristic patterns that progresses with flare-ups and remissions. Cumulative damage results in disability and, eventually, death. This report aimed to describe a case of FOP to highlight the importance of early diagnosis of this rare condition. CASE REPORT: We describe the case of a 3-year-old female diagnosed with congenital hallux valgus, who initially presented with soft tissue tumors, predominantly in the neck and chest, with partial remission. Multiple diagnostic tests were performed, including biopsies and magnetic resonance imaging, with nonspecific results. We observed ossification of the biceps brachii muscle during evolution. The molecular genetic study found a heterozygous ACVR1 gene mutation that confirmed FOP. CONCLUSIONS: Knowledge of this rare disease by pediatricians is critical for an early diagnosis and for avoiding unnecessary invasive procedures that may promote disease progression. In case of clinical suspicion, performing an early molecular study is suggested to detect ACVR1 gene mutations. The treatment of FOP is symptomatic and focused on maintaining physical function and family support.

INTRODUCCIÓN: La fibrodisplasia osificante progresiva (FOP) es una enfermedad autosómica dominante rara que afecta el tejido conectivo, cuya causa principal son mutaciones de novo del gen ACVR1. Se trata de una enfermedad con malformaciones congénitas de los primeros ortejos y osificación heterotópica en patrones característicos que progresa en empujes y remisiones. El daño acumulativo provoca discapacidad y, eventualmente, la muerte. El objetivo de este trabajo fue describir un caso de FOP para favorecer el diagnóstico precoz de esta enfermedad infrecuente. CASO CLÍNICO: Se describe el caso de una paciente de 3 años, portadora de hallux valgus congénito, que inicialmente presentó tumoraciones dolorosas de tejidos blandos, de predominio en cuello y tórax, con remisión parcial de las mismas. Se realizaron múltiples pruebas diagnósticas, incluyendo biopsias e imágenes de resonancia magnética con resultados inespecíficos. En la evolución se observó osificación de músculo bíceps braquial. El estudio genético molecular encontró una mutación del gen ACVR1 en heterocigosis que confirmó el diagnóstico de FOP. CONCLUSIONES: El conocimiento de esta enfermedad por los pediatras es clave para realizar un diagnóstico precoz y evitar procedimientos invasivos innecesarios que pueden promover la progresión de la enfermedad. Ante la sospecha clínica, se sugiere realizar tempranamente el estudio molecular para detectar mutaciones del gen ACVR1. El tratamiento de la FOP es sintomático, centrado en el mantenimiento de la función física y el apoyo familiar.

Computational and mitochondrial functional studies of novel compound heterozygous variants in SPATA5 gene support a causal link with epileptogenic encephalopathy.

The SPATA5 gene encodes a 892 amino-acids long protein that has a putative mitochondrial targeting sequence and has been proposed to function in maintenance of mitochondrial function and integrity during mouse spermatogenesis. Several studies have associated homozygous or compound heterozygous mutations in SPATA5 gene to microcephaly, intellectual disability, seizures and hearing loss. This suggests a role of the SPATA5 gene also in neuronal development. Recently, our group presented results validating the use of blood cells for the assessment of mitochondrial function for diagnosis and follow-up of mitochondrial disease, minimizing the need for invasive procedures such as muscle biopsy. In this study, we were able to diagnose a patient with epileptogenic encephalopathy using next generation sequencing. We found two novel compound heterozygous variants in SPATA5 that are most likely causative. To analyze the impact of SPATA5 mutations on mitochondrial functional studies directly on the patients' mononuclear cells and platelets were undertaken. Oxygen consumption rates in platelets and PBMCs were impaired in the patient when compared to a healthy control. Also, a decrease in mitochondrial mass was observed in the patient monocytes with respect to the control. This suggests a true pathogenic effect of the mutations in mitochondrial function, especially in energy production and possibly biogenesis, leading to the observed phenotype.

Fibrodysplasia ossificans progressiva in a 3-year-old female patient / Fibrodisplasia osificante progresiva en una paciente de 3 años

Abstract Background: Fibrodysplasia ossificans progressiva (FOP) is a rare autosomal dominant disease affecting connective tissue, primarily caused by de novo mutations of the ACVR1 gene. FOP is a disease with congenital malformations of the toes and heterotopic ossification in characteristic patterns that progresses with flare-ups and remissions. Cumulative damage results in disability and, eventually, death. This report aimed to describe a case of FOP to highlight the importance of early diagnosis of this rare condition. Case report: We describe the case of a 3-year-old female diagnosed with congenital hallux valgus, who initially presented with soft tissue tumors, predominantly in the neck and chest, with partial remission. Multiple diagnostic tests were performed, including biopsies and magnetic resonance imaging, with nonspecific results. We observed ossification of the biceps brachii muscle during evolution. The molecular genetic study found a heterozygous ACVR1 gene mutation that confirmed FOP. Conclusions: Knowledge of this rare disease by pediatricians is critical for an early diagnosis and for avoiding unnecessary invasive procedures that may promote disease progression. In case of clinical suspicion, performing an early molecular study is suggested to detect ACVR1 gene mutations. The treatment of FOP is symptomatic and focused on maintaining physical function and family support.

Resumen Introducción: La fibrodisplasia osificante progresiva (FOP) es una enfermedad autosómica dominante rara que afecta el tejido conectivo, cuya causa principal son mutaciones de novo del gen ACVR1. Se trata de una enfermedad con malformaciones congénitas de los primeros ortejos y osificación heterotópica en patrones característicos que progresa en empujes y remisiones. El daño acumulativo provoca discapacidad y, eventualmente, la muerte. El objetivo de este trabajo fue describir un caso de FOP para favorecer el diagnóstico precoz de esta enfermedad infrecuente. Caso clínico: Se describe el caso de una paciente de 3 años, portadora de hallux valgus congénito, que inicialmente presentó tumoraciones dolorosas de tejidos blandos, de predominio en cuello y tórax, con remisión parcial de las mismas. Se realizaron múltiples pruebas diagnósticas, incluyendo biopsias e imágenes de resonancia magnética con resultados inespecíficos. En la evolución se observó osificación de músculo bíceps braquial. El estudio genético molecular encontró una mutación del gen ACVR1 en heterocigosis que confirmó el diagnóstico de FOP. Conclusiones: El conocimiento de esta enfermedad por los pediatras es clave para realizar un diagnóstico precoz y evitar procedimientos invasivos innecesarios que pueden promover la progresión de la enfermedad. Ante la sospecha clínica, se sugiere realizar tempranamente el estudio molecular para detectar mutaciones del gen ACVR1. El tratamiento de la FOP es sintomático, centrado en el mantenimiento de la función física y el apoyo familiar.

Novel frameshift mutation in LIS1 gene is a probable cause of lissencephaly: a case report.

BACKGROUND: Lissencephaly (LIS) is a cortical malformation, characterized by smooth or nearly smooth cerebral surface and a shortage of gyral and sulcal development, which is caused by deficient neuronal migration during embryogenesis. Neuronal migration involves many gene products, among which is the product of the PAFAH1B1 gene, associated with this disease. LIS is a rare disease, characterized by low population frequency, and with non-specific clinical symptoms such as early epilepsy, developmental delay or cerebral palsy-like motor problems. Given that high-throughput sequencing techniques have been improving diagnosis, we have chosen this technique for addressing this patient. CASE PRESENTATION: We present the case of a seven years old male patient with an undiagnosed rare disease, with non-specific clinical symptoms possibly compatible with lissencephaly. The patient was enrolled in a study that included the sequencing of his whole genome. Sequence data was analyzed following a bioinformatic pipeline. The variants obtained were annotated and then subjected to different filters for prioritization. Also mitochondrial genome was analyzed. A novel candidate frameshift insertion in known PAFAH1B1 gene was found, explaining the index case phenotype. The assessment through in silico tools reported that it causes nonsense mediated mechanisms and that it is damaging with high confidence scores. The insertion causes a change in the reading frame, and produces a premature stop codon, severely affecting the protein function and probably the silencing of one allele. The healthy mother did not carry the mutation, and the unaffected father was not available for analysis. CONCLUSIONS: Through this work we found a novel de novo mutation in LIS1/PAFAH1B1 gene, as a likely cause of a rare disease in a young boy with non-specific clinical symptoms. The mutation found correlates with the phenotype studied since the loss of function in the gene product has already been described in this condition. Since there are no other variants in the PAFAH1B1 gene with low population frequency and due to family history, a de novo disease mechanism is proposed.

Whole genome sequencing reveals a frameshift mutation and a large deletion in YY1AP1 in a girl with a panvascular artery disease.

BACKGROUND: Rare diseases are pathologies that affect less than 1 in 2000 people. They are difficult to diagnose due to their low frequency and their often highly heterogeneous symptoms. Rare diseases have in general a high impact on the quality of life and life expectancy of patients, which are in general children or young people. The advent of high-throughput sequencing techniques has improved diagnosis in several different areas, from pediatrics, achieving a diagnostic rate of 41% with whole genome sequencing (WGS) and 36% with whole exome sequencing, to neurology, achieving a diagnostic rate between 47 and 48.5% with WGS. This evidence has encouraged our group to pursue a molecular diagnosis using WGS for this and several other patients with rare diseases. RESULTS: We used whole genome sequencing to achieve a molecular diagnosis of a 7-year-old girl with a severe panvascular artery disease that remained for several years undiagnosed. We found a frameshift variant in one copy and a large deletion involving two exons in the other copy of a gene called YY1AP1. This gene is related to Grange syndrome, a recessive rare disease, whose symptoms include stenosis or occlusion of multiple arteries, congenital heart defects, brachydactyly, syndactyly, bone fragility, and learning disabilities. Bioinformatic analyses propose these mutations as the most likely cause of the disease, according to its frequency, in silico predictors, conservation analyses, and effect on the protein product. Additionally, we confirmed one mutation in each parent, supporting a compound heterozygous status in the child. CONCLUSIONS: In general, we think that this finding can contribute to the use of whole genome sequencing as a diagnosis tool of rare diseases, and in particular, it can enhance the set of known mutations associated with different diseases.

Novel frameshift mutation in PURA gene causes severe encephalopathy of unclear cause.

BACKGROUND: The etiology of many genetic diseases is challenging. This is especially true for developmental disorders of the central nervous system, since several genes can be involved. Many of such pathologies are considered rare diseases, since they affect less than 1 in 2000 people. Due to their low frequency, they present several difficulties for patients, from the delay in the diagnosis to the lack of treatments. Next-generation sequencing techniques have improved the search for diagnosis in several pathologies. Many studies have shown that the use of whole-exome/genome sequencing in rare Mendelian diseases has a diagnostic yield between 30% and 50% depending on the disease. METHODS: Here, we present the case of an undiagnosed 6-year-old boy with severe encephalopathy of unclear cause, whose etiological diagnosis was achieved by whole-genome sequencing. RESULTS: We found a novel variant that has not been previously reported in patients nor it has been described in GnomAD. Segregation analysis supports a de novo mutation, since it is not present in healthy parents. The change is predicted to be harmful to protein function, since it falls in the first quarter of the protein producing an altered reading frame and generating a premature stop codon. Additionally, the variant is classified as pathogenic according to ACMG criteria (PVS1, PM2, and PP3). Furthermore, there are several reported frameshift mutations in nearby codons as well as nonsense mutations that are predicted as pathogenic in other studies. CONCLUSION: We found a novel de novo frameshift mutation in the PURA gene (MIM number 600473), c.151_161del, with sufficient evidence of its pathogenicity.

Síndrome branquio-oto-renal. Presentación de un caso / Branchio-oto-renal syndrome. Case study / Síndrome brânquio-otorrenal. Relato de caso

Resumen: El síndrome branquio-oto-renal (BOR) es un trastorno hereditario autosómico dominante, poco frecuente, que se presenta con expresividad variable y penetrancia reducida, con gran heterogeneidad clínica inter e intrafamiliar. Es causado por alteraciones del desarrollo del oído, riñones y de los segundos arcos branquiales, estructura que en el embrión en desarrollo da origen a tejidos del cuello. Los hallazgos clínicos más comunes son las fístulas o quistes en el cuello, déficit auditivo, malformaciones del oído externo con apéndices u hoyuelos preauriculares y afectación renal uni o bilateral que va de moderada a severa. El síndrome es causado principalmente por mutaciones en el gen EYA1 que actúa como regulador transcripcional durante la embriogénesis, las cuales se detectan en el 40% de los pacientes. Presentamos un caso ilustrativo de síndrome de BOR que se mostró con hallazgos clínicos sugestivos como fositas preauriculares, fístulas branquiales, hipoacusia severa con anomalías anatómicas del oído, compromiso renal y antecedentes familiares. En este paciente se encontró una variante patogénica en el gen EYA1: c.1081C>T (p.Arg361TER). Esta es considerada una variante nula, ya que provoca un codón de terminación prematuro que conduce a una pérdida de la función de la proteína. Dada la expresividad variable del síndrome de BOR, el diagnóstico molecular cobra importancia para evitar errores diagnósticos, iniciar el seguimiento familiar en cascada con el fin de identificar familiares afectados y para implementar medidas preventivas tendientes a disminuir la morbilidad y mortalidad causadas por este síndrome.

Summary: The branchio-oto-renal syndrome (BOR) is an uncommon autosomal dominant genetic disorder with variable expressivity, reduced penetrance and significant clinical and intra-familial heterogeneity. It is caused by alterations in the development of the ears, kidneys and second branchial arches, a structure that in developing embryos produces neck tissue. The most common clinical findings are neck fistulas or cysts, hearing loss, malformations of the outer ear with appendices and/or pre-auricular dimples and unilateral or bilateral moderate to severe renal involvement. The syndrome is mainly caused by mutations in the EYA1 gene that acts as a transcriptional regulator during embryogenesis, and which are detected in 40% of patients. We hereby introduce a representative case of BOR syndrome that showed suggestive clinical findings such as preauricular holes, branchial fistulas, severe hearing loss with anatomical anomalies of the ear, and renal impairment. In this case, we found a pathogenic variant in the EYA1 gene: c.1081C>T (p.Arg361TER). This is considered a null variant, since it causes a premature stop codon that leads to protein function loss. Given the BOR Syndrome variable expressivity, molecular diagnosis is relevant to prevent diagnostic errors, initiate familial cascade screening in order to identify affected relatives and to implement preventive measures aimed at reducing the morbidity and mortality caused by this syndrome.

Resumo: A síndrome branquio-oto-renal (BOR) é uma desordem genética autossômica dominante incomum com expressividade variável, penetrância reduzida e significativa heterogeneidade clínica e intrafamiliar. É causada por alterações no desenvolvimento das orelhas, rins e segundos arcos branquiais, as quais durante o desenvolvimento do embrião produzem tecido no pescoço. Os achados clínicos mais comuns são fístulas ou cistos no pescoço, déficit auditivo, malformações da orelha externa com apêndices e / ou seios pré-auriculares e comprometimento renal moderado a grave unilateral ou bilateral. A síndrome é causada principalmente por mutações no gene EYA1, que atua como regulador da transcrição durante a embriogênese e é detectada em 40% dos pacientes. Introduzimos aqui um caso representativo da síndrome BOR que apresentou achados clínicos sugestivos, como fossas pré-auriculares, fístulas branquiais, perda auditiva grave com anomalias anatômicas da orelha e comprometimento renal. Nesse caso, encontramos uma variante patogênica no gene EYA1: c.1081C> T (p.Arg361TER). Isso é considerado uma variante nula, pois causa um códon de parada prematuro que leva a uma perda da função da proteína. Dada a expressividade variável da síndrome do ROR, o diagnóstico molecular é relevante para evitar erros de diagnóstico, iniciar o rastreamento em cascata familiar, a fim de identificar os familiares afetados e implementar medidas preventivas destinadas a reduzir a morbimortalidade causada pela síndrome.

Deep sequencing discovery of causal mtDNA mutations in a patient with unspecific neurological disease.

Mitochondrial diseases (MD) are a group of diseases that can be caused by either mutations in the mitochondrial genome or nuclear DNA. MD may be difficult to diagnose since very often they are highly heterogeneous and with overlapping phenotypes. Molecular genomics approaches, especially NGS have helped in this sense. In this study we have sequenced the mitochondrial genome of a girl with an unspecific neurological disorder and her mother. The later, while neurologically unaffected, suffers from a myopathy without clear cause. We were able to detect two non-synonymous mutations in the MT-ATP6 gene, which we propose are strong candidates for causative agents. 9017C as the main candidate present at high heteroplasmy frequency in the patient (83,2%) and moderate in the mother (45,4%) while it has a low frequency in the general population. It might act alone or in conjunction with 9010A as an accessory mutation. Evolutionary analysis showed that both mutations were located in a critical position in the F0 a subunit, from F0-F1 ATPase. Functional studies showed that carriers of those mutations in comparison to an unaffected individual (father) presented a decrease in the basal and ATP-dependent oxygen consumption rate and a decrease in the maximum respiration rate.

A novel mutation in the OAR domain of the ARX gene.

Mutations in ARX gene should be considered in patients with mental disability or/and epilepsy. It is an X-linked gene that has pleiotropic effects. Here, we report the case of a boy diagnosed with Ohtahara syndrome. We performed the molecular analysis of the gene and identified a new missense mutation.

3697G>A in MT-ND1 is a causative mutation in mitochondrial disease.

Mitochondrial diseases are a group of clinically heterogeneous disorders that can be difficult to diagnose. We report a two and a half year old girl with clinical symptoms compatible with Leigh disease but with no definitive diagnosis. Using next generation sequencing we found that mutation 3697G>A was responsible for the patient's clinical symptoms. Corroboration was performed via segregation analysis in mother and sister and by evolutionary analysis that showed that the mutation is located in a highly conserved region across a wide range of species. Functional analyses corroborated the mutation effect and indicated that the pathophysiological alterations were partially restored by Coenzyme Q10. In addition, we proposed that the presence of the mutation at high frequencies causes the phenotype in the patient, while other family members with intermediate levels of heteroplasmy are symptoms-free.

Hospitalización relacionada con defectos congénitos en el Centro Hospitalario Pereira Rossell / Hospitalization related to birth defects at the Pereira Rossell Hospital Center

Introducción: las anomalías congénitas representan una de las principales causas de mortalidad infantil en Uruguay. Son responsables de hasta 25% de las internaciones en centros de alta complejidad. Objetivo: aportar al conocimiento de la carga de enfermedad por anomalías congénitos. La frecuencia de hospitalizaciones, sus características clínicas y tipos de defectos congénitos, motivos de hospitalización, duración de estadía hospitalaria, niveles y tipos de cuidados requeridos. Método: estudio descriptivo, prospectivo, se incluyeron todos los menores de 15 años portadores de defectos congénitos hospitalizados en áreas de cuidados moderados del Hospital de Niños del CHPR en un período de 6 meses independientemente del motivo de ingreso. Se excluyeron los servicios de neonatología y los pisos quirúrgicos. Resultados: del total de niños ingresados, 5,1% presentaban defectos congénitos. El diagnóstico fue prenatal en 13,6%. El defecto fue único en 75%. El ingreso fue por patología vinculada con el defecto congénito en el 80%. La media de estadía hospitalaria de estos niños fue 9,5 días, superior a la media de la estadía hospitalaria general de 4,6 días (p<0,05). El 5,2% de los niños requirieron ingreso a unidad de cuidado intensivo (UCI). Conclusiones: es la primera descripción de frecuencia y características de la hospitalización relacionada con defectos congénitos en el área de cuidados moderados del Hospital de Niños del CHPR. A pesar del sesgo de inclusión, los hallazgos demuestran la demanda asistencial especializada y elevada morbilidad de estos niños. Futuras investigaciones son necesarias para analizar factores de riesgo relacionados con este problema de salud.

Introduction: congenital anomalies represent one of the main causes of child mortality in Uruguay. Up to 25% of hospitalizations in high-complexity centers are due to pathologies related with congenital defects. Objective: to contribute to the knowledge of disease burden due to congenital anomalies. The frequency of hospitalizations, their clinical characteristics, and the types of congenital defects, the reasons for hospitalization, the duration of hospital stay, and the levels and types of caring required are explored. Method: descriptive, prospective study, in which all patients under 15 years of age, carriers of congenital defects, hospitalized in intermediate care areas of the CHPR Children’s Hospital for a period of 6 months, were included, regardless of the reason for admission. Neonatology services and surgical wards were excluded. Results: out of the total of admitted children, 5.1% presented congenital defects. Diagnosis was prenatal in 13.6%. The defect was single in 75%. The reasons for admission were pathologies related to the congenital defects in 80%. The average hospital stay of these children was 9.5 days, higher than the general average hospital stay which was 4.6 days (p<0.05). 15.2% of the children required admission to the intensive care unit (ICU). Conclusions: it is the first description of the frequency and characteristics of hospitalization related to congenital defects in the intermediate care area of the CHPR Children’s Hospital. In spite of the inclusion bias, findings show the specialized caring demand and the high morbidity of these children. Future research is needed to analyze the risk factors related to this health issue.

[Advances in the identification of the aetiology of mental retardation]. / Avances en la identificación etiológica del retraso mental.

Despite the advances made in the field of genetics, neuroimaging and metabolic diseases, half the children with mental retardation remain without an aetiological diagnosis. A genetic base is estimated to be present in 40% of cases, environmental teratogens and prematurity in 20%, metabolic diseases in 1-5% and multifactor causes in 3-12%. The family history, the detailed medical records required by dysmorphology and the neurological examination will make it possible to establish or suspect a diagnosis in two thirds of the cases and, in the others, scanning tests will be able to confirm an aetiology. The order of the studies will be guided by the clinical picture: karyotype if a chromosome pathology is suspected, neuroimaging if there is some abnormality in the neurological examination and specific genetic or neurometabolic studies to confirm the clinical presumption. The estimated diagnostic performance of the different techniques is: karyotype, 9%; fragile X, 5%; subtelomeric abnormalities, 4%; neurometabolic diseases, 1%, and new microarray techniques, 19%. As a result of the higher performance and cost-benefit ratio, today the recommended procedure, as the first line of treatment for unexplainable cases of mental retardation, is the study of microarrays. Although the outcomes of these tests are complex and require confirmation and careful interpretation by a specialist in medical genetics, the advances in their technological development and resolution, together with lower costs make this technique a fundamental tool in the identification of the aetiology in these children.

TITLE: Avances en la identificacion etiologica del retraso mental.A pesar de los avances en el campo de la genetica, la neuroimagen y las enfermedades metabolicas, la mitad de los niños con retraso mental permanecen sin diagnostico etiologico. Se estima una base genetica en un 40% de los casos, teratogenos ambientales y prematuridad en un 20%, enfermedades metabolicas en un 1-5% y causas multifactoriales en un 3-12%. Los antecedentes familiares, la historia clinica detallada que precisa la dismorfologia y el examen neurologico permitiran establecer o sospechar un diagnostico en dos tercios de los casos y, en los restantes, las pruebas de barrido podran confirmar una etiologia. El orden de los estudios guiara la clinica: cariotipo si se sospecha de cromosomopatia, neuroimagen si existe una alteracion del examen neurologico y estudios geneticos especificos o neurometabolicos para confirmar la presuncion clinica. El rendimiento diagnostico estimado de las diferentes tecnicas es: cariotipo, 9%; X fragil, 5%; anomalias subtelomericas, 4%; enfermedades neurometabolicas, 1%, y nuevas tecnicas de microarrays, 19%. Debido al mayor rendimiento y coste-beneficio, actualmente se recomienda, como primera linea para los retrasos mentales inexplicables, los estudios de microarrays. Si bien los resultados de estas pruebas son complejos y requieren confirmacion e interpretacion cuidadosa de un especialista en genetica medica, los avances en su desarrollo tecnologico, resolucion y disminucion de los costes determinan que se transforme en una herramienta fundamental en la identificacion etiologica de estos niños.

Laringitis herpética. A propósito de un caso clínico / Herpetic laryngitis. Apropos of a clinical case

La laringitis aguda en niños es una patología frecuente, autolimitada, de breve duración: 2 a 7 días, causada por virus como influenza A y B, parainfluenza 1, 2 y 3, virus respiratorio sincitial (VRS) y adenovirus.Las infecciones prolongadas pueden involucrar otros patógenos; han sido reportados algunos casos de laringitis causadas por infecciones herpéticas, sobre todo por el virus herpes simple tipo 1 (VHS-1).Se sugiere la evaluación endoscópica de la vía aérea en casos de laringitis prolongadas para el diagnóstico e implementar medidas terapéuticas específicas para evitar complicaciones potencialmente graves. El uso de aciclovir ha demostrado ser efectivo en el tratamiento, siendo controvertido el uso de corticoides y antibióticos.Se presenta el caso de una niña de 7 meses con laringitis por Herpes virus, tratado con aciclovir...