Specific combinations of biallelic POLR3A variants cause Wiedemann-Rautenstrauch syndrome.

BACKGROUND: Wiedemann-Rautenstrauch syndrome (WRS) is a form of segmental progeria presenting neonatally, characterised by growth retardation, sparse scalp hair, generalised lipodystrophy with characteristic local fatty tissue accumulations and unusual face. We aimed to understand its molecular cause. METHODS: We performed exome sequencing in two families, targeted sequencing in 10 other families and performed in silico modelling studies and transcript processing analyses to explore the structural and functional consequences of the identified variants. RESULTS: Biallelic POLR3A variants were identified in eight affected individuals and monoallelic variants of the same gene in four other individuals. In the latter, lack of genetic material precluded further analyses. Multiple variants were found to affect POLR3A transcript processing and were mostly located in deep intronic regions, making clinical suspicion fundamental to detection. While biallelic POLR3A variants have been previously reported in 4H syndrome and adolescent-onset progressive spastic ataxia, recurrent haplotypes specifically occurring in individuals with WRS were detected. All WRS-associated POLR3A amino acid changes were predicted to perturb substantially POLR3A structure/function. CONCLUSION: Biallelic mutations in POLR3A, which encodes for the largest subunit of the DNA-dependent RNA polymerase III, underlie WRS. No isolated functional sites in POLR3A explain the phenotype variability in POLR3A-related disorders. We suggest that specific combinations of compound heterozygous variants must be present to cause the WRS phenotype. Our findings expand the molecular mechanisms contributing to progeroid disorders.

Genetic variability analysis in a population from Bogotá: Towards a haplotype map / Análisis de la variabilidad genética de una muestra de la población de Bogotá: hacia la constitución de un mapa de haplotipos

Introduction: The HapMap and the 1000 Genomes projects have been important for understanding the genetic component of common diseases and normal phenotypes. However, the Colombian genetic variability included in these projects is not fully representative of our country. Objective: To contribute to the knowledge of the Colombian genetic variability through the genomic study of a sample of individuals from Bogotá. Materials and methods: A total of 2,372,784 genetic markers were genotyped in 32 individuals born in Bogotá whose parents are from the same region, using the Illumina™ platform. The genetic variability levels were determined and compared with the data available from other populations of the 1000 Genomes Project. Results: The genetic variability detected in the individuals from Bogotá was similar to those with shared ancestry. However, despite the low levels of genetic differentiation between Bogotá and Medellín, populations the principal component analysis suggested a different genetic composition in them. Conclusions: Our genomic analysis of a Bogotá sample allowed us to detect similarities and differences with other American populations. The increase of the Bogotá sample and the inclusion of samples from other regions of the country will improve our understanding of the genetic variability in Colombia, essential for studies of human health and the prevention and treatment of common diseases in our country.

Introducción. Los proyectos del mapa de haplotipos (HapMap) y de los 1.000 genomas han sido fundamentales para la compresión del componente genético de las enfermedades comunes y los fenotipos normales. Sin embargo, la variabilidad genética colombiana incluida en estos proyectos no es representativa del país. Objetivo. Contribuir al conocimiento de la variabilidad genética de la población colombiana a partir del estudio genómico de una muestra de individuos de Bogotá. Materiales y métodos. Se genotipificaron 2'372.784 marcadores genéticos de 32 individuos nacidos en Bogotá y de padres originarios de la misma ciudad utilizando la plataforma Illumina™. Los niveles de variabilidad genética se determinaron y se compararon con los datos disponibles de otras poblaciones del proyecto de los 1.000 genomas. Resultados. Los individuos analizados presentaron una variabilidad genética semejante a la de poblaciones con las que comparten ancestros. No obstante, a pesar de la poca diferenciación genética detectada en la población de Bogotá y en la de Medellín, el análisis de los componentes principales sugiere una composición genética diferente en las dos poblaciones. Conclusiones. El análisis genómico de la muestra de Bogotá permitió detectar similitudes y diferencias con otras poblaciones americanas. El aumento de tamaño de la muestra bogotana y la inclusión de muestras de otras regiones del país permitirán una mejor compresión de la variabilidad genética en Colombia, lo cual es fundamental para los estudios de salud humana, y la prevención y el tratamiento de enfermedades comunes en el país.

Análisis de la variabilidad genética de una muestra de la población de Bogotá: hacia la constitución de un mapa de haplotipos / Genetic variability analysis in a population from Bogotá: Towards a haplotype map

Resumen Introducción. Los proyectos del mapa de haplotipos (HapMap) y de los 1.000 genomas han sido fundamentales para la compresión del componente genético de las enfermedades comunes y los fenotipos normales. Sin embargo, la variabilidad genética colombiana incluida en estos proyectos no es representativa del país. Objetivo. Contribuir al conocimiento de la variabilidad genética de la población colombiana a partir del estudio genómico de una muestra de individuos de Bogotá. Materiales y métodos. Se genotipificaron 2'372.784 marcadores genéticos de 32 individuos nacidos en Bogotá y de padres originarios de la misma ciudad utilizando la plataforma Illumina™. Los niveles de variabilidad genética se determinaron y se compararon con los datos disponibles de otras poblaciones del proyecto de los 1.000 genomas. Resultados. Los individuos analizados presentaron una variabilidad genética semejante a la de poblaciones con las que comparten ancestros. No obstante, a pesar de la poca diferenciación genética detectada en la población de Bogotá y en la de Medellín, el análisis de los componentes principales sugiere una composición genética diferente en las dos poblaciones. Conclusiones. El análisis genómico de la muestra de Bogotá permitió detectar similitudes y diferencias con otras poblaciones americanas. El aumento de tamaño de la muestra bogotana y la inclusión de muestras de otras regiones del país permitirán una mejor compresión de la variabilidad genética en Colombia, lo cual es fundamental para los estudios de salud humana, y la prevención y el tratamiento de enfermedades comunes en el país.

Abstract Introduction: The HapMap and the 1000 Genomes projects have been important for understanding the genetic component of common diseases and normal phenotypes. However, the Colombian genetic variability included in these projects is not fully representative of our country. Objective: To contribute to the knowledge of the Colombian genetic variability through the genomic study of a sample of individuals from Bogotá. Materials and methods: A total of 2,372,784 genetic markers were genotyped in 32 individuals born in Bogotá whose parents are from the same region, using the Illumina™ platform. The genetic variability levels were determined and compared with the data available from other populations of the 1000 Genomes Project. Results: The genetic variability detected in the individuals from Bogotá was similar to those with shared ancestry. However, despite the low levels of genetic differentiation between Bogotá and Medellín, populations the principal component analysis suggested a different genetic composition in them. Conclusions: Our genomic analysis of a Bogotá sample allowed us to detect similarities and differences with other American populations. The increase of the Bogotá sample and the inclusion of samples from other regions of the country will improve our understanding of the genetic variability in Colombia, essential for studies of human health and the prevention and treatment of common diseases in our country.

Infecciones y anemia en estudiantes de la parroquia Guapán, Azogues, Ecuador / Infections and anemia in students of theGuapán parish, Azogues, Ecuador

Introducción: Las unidades educativas constituyen un entorno ideal para el diagnóstico de enfermedades y la promoción de salud. Objetivo:Identificar la presencia de enfermedades infecciosas y anemia en los estudiantes de la Unidad Educativa Ezequiel Cárdenas Espinoza de la parroquia Guapán del cantón Azogues en Ecuador y tomar medidas correctivas al respecto.Métodos:Se realizó un estudio observacional, descriptivo, transversal y prospectivo.El universo fueron los316 estudiantes matriculados enla Unidad Educativa Ezequiel Cárdenas Espinoza de la parroquia Guapán del cantón Azogues en Ecuador durante el periodo académico 2013-2014. La muestra fue coincidente pues setrabajó con todos los estudiantes de la institución en edades comprendidas entre 11 y 17 años de edad. Las variables evaluadas fueron edad, sexo y enfermedades más frecuentes para lo cual se utilizó como técnicas el coproparasitario, examen de sangre (hemoglobina), y examen elemental y microscópico de orina.Resultados:El 21.6% de los estudiantes evaluados presentaron parasitosis intestinal. La parasitosis más frecuente fue causada por Ameba histolytica con un 60% y 25% de Ascaris lumbricoides. El sexo predominantemente afectado fue el masculino con el 71%. Solo una estudiante del 8vo curso, correspondiente al 1.3% y un 5% de los estudiantes de 9no curso presentaron anemia. En todos los cursos se diagnosticaron estudiantes con infección de vías urinarias, representando el 15.2%. El 77.1% de los afectados fue del sexo femenino.Conclusiones:La presencia de enfermedades infecciosas y anemia determina el diseño de estrategias educativas a estudiantes, padres de familia y profesores de la institución

Introduction:The educational units constitute an ideal environment for diagnosing diseases and promoting health.Objective:To identify the presence of infectious diseases and anemia in the students of the Ezequiel Cárdenas Espinoza Educational Unit of the Guapan parish of the Azogues canton in Ecuador and to take corrective measures in this regard.Methods:An observational, descriptive, cross-sectional and prospective study was carried out. The universe was the 316 students enrolled in the Ezequiel Cárdenas Espinoza Educational Unit of the Guapan parish of the Azogues canton in Ecuador during the 2013-2014 academic period. The sample was coincident because it worked with all the students of the institution in ages between 11 and 17 years of age. The variables evaluated were age, sex and most frequent diseases for which coproparasitic, blood test (hemoglobin), and elementary and microscopic urine tests were used as techniques.Results:21.6% of the students evaluated presented intestinal parasitosis. The most frequent parasitosis was caused by Ameba histolytica with 60% and 25% of Ascaris lumbricoides. The predominantly affectedsex was male with 71%. Only one student in the 8th grade, corresponding to 1.3% and 5% of the 9th grade students, presented anemia. In all the courses, students with urinary tract infection were diagnosed, representing 15.2%. 77.1% of those affected were female.Conclusions:The presence of infectious diseases and anemia determines the design of educational strategies for students, parents and teachers of the institution.

Amino acid tissue levels and GABAA receptor binding in the developing rat cerebellum following status epilepticus.

Incidence of status epilepticus (SE) is higher in children than in adults and SE can be induced in developing rats. The cerebellum can be affected after SE; however, consequences of cerebellar amino acid transmission have been poorly studied. The goal of this study was to determine amino acid tissue concentration and GABA(A) receptor binding in the immature rat cerebellum after an episode of SE. Thirteen-day-old (P13) rat pups received intraperitoneal injections of lithium chloride (3 mEq/kg). Twenty hours later, on P14, SE was induced by subcutaneous injection of pilocarpine hydrochloride (60 mg/kg). Control animals were given an equal volume of saline subcutaneously. Animals were killed 24h after SE induction, the cerebellum was quickly removed, and the vermis and hemispheres were rapidly dissected out on ice. Amino acid tissue concentrations in the vermis and hemispheres were evaluated by HPLC and fluorescent detection. GABA(A) receptor binding in the medial vermis was analyzed by in vitro autoradiography. SE increased the tissue levels of the inhibitory amino acids taurine (80%) and alanine (91%), as well as glutamine (168%) in the cerebellar hemisphere; no changes were observed in the vermis. SE did not modify GABA(A) receptor binding in any cerebellar lobule from the vermis. Our data demonstrate that SE produces region-specific changes in amino acid concentrations in the developing cerebellum.