ABSTRACT
Congenital hearing loss is the most common birth defect, estimated to affect 2-3 in every 1000 births, with ~50-60% of those related to genetic causes. Technological advances enabled the identification of hundreds of genes related to hearing loss (HL), with important implications for patients, their families, and the community. Despite these advances, in Latin America, the population with hearing loss remains underdiagnosed, with most studies focusing on a single locus encompassing the GJB2/GJB6 genes. Here we discuss how current and emerging genetic knowledge has the potential to alter the approach to diagnosis and management of hearing loss, which is the current situation in Latin America, and the barriers that still need to be overcome.
Subject(s)
Deafness , Hearing Loss , Humans , Connexins/genetics , Connexin 26/genetics , Mutation , Latin America/epidemiology , Genetic Testing , Hearing Loss/diagnosis , Hearing Loss/genetics , Deafness/diagnosis , Deafness/geneticsABSTRACT
GATAD2B (GATA zinc finger domain containing 2B) variants are associated with the neurodevelopmental syndrome GAND, characterized by intellectual disability (ID), infantile hypotonia, apraxia of speech, epilepsy, macrocephaly and distinct facial features. GATAD2B encodes for a subunit of the Nucleosome Remodeling and Histone Deacetylase (NuRD) complex. NuRD controls transcriptional programs critical for proper neurodevelopment by coupling histone deacetylase with ATP-dependent chromatin remodeling activity. To study mechanisms of pathogenesis for GAND, we characterized a mouse model harboring an inactivating mutation in Gatad2b. Homozygous Gatad2b mutants die perinatally, while haploinsufficient Gatad2b mice exhibit behavioral abnormalities resembling the clinical features of GAND patients. We also observed abnormal cortical patterning, and cellular proportions and cell-specific alterations in the developmental transcriptome in these mice. scRNAseq of embryonic cortex indicated misexpression of genes key for corticogenesis and associated with neurodevelopmental syndromes such as Bcl11b, Nfia and H3f3b and Sox5. These data suggest a crucial role for Gatad2b in brain development.
Subject(s)
Intellectual Disability , Repressor Proteins , Humans , Animals , Mice , GATA Transcription Factors/genetics , Intellectual Disability/genetics , Intellectual Disability/complications , Transcription Factors/genetics , Histone Deacetylases , Syndrome , Tumor Suppressor ProteinsABSTRACT
BACKGROUND: Gut microbiota is a complex organized collection of microorganisms that confers multiple metabolic advantages to the host. The reduced diversity and proportion of specific gut microbial species have been associated with obesity and metabolic disorders. Multidimensional interventions, including modifications in dietary and physical activity habits, are associated with favorable changes in microbiota composition. This pilot study aimed to evaluate changes in the gut microbiota composition of Mexican children with obesity before and after a 6-week multidimensional intervention. METHODS: Blood and stool samples were collected, and anthropometric measurements were obtained from six children with obesity before and after the intervention. The intervention consisted of modeling a hypo energetic diet and giving nutritional and physical activation recommendations. DNA from stool samples was used to characterize gut microbial composition by sequencing the 16S rRNA gene. RESULTS: The decrease in waist circumference was associated with increased Odoribacter relative abundance. However, gut microbiota composition and diversity remained unchanged. CONCLUSIONS: Although no modifications in the body mass index, body fat, composition, or diversity of the gut microbiota were observed with the intervention, it was possible to associate the reduction in waist circumference with the presence of Odoribacter after a multidimensional intervention in Mexican children with obesity.
INTRODUCCIÓN: La microbiota intestinal es un conjunto de microorganismos organizados de forma compleja que confieren múltiples ventajas metabólicas al hospedero. La reducida diversidad y la proporción de ciertas especies sobre otras se ha asociado con obesidad y enfermedades metabólicas. Las intervenciones multidimensionales, que incluyen modificaciones en los hábitos alimentarios y de actividad física, se asocian con cambios favorables en la composición de la microbiota. El objetivo de este estudio piloto fue evaluar la composición de la microbiota intestinal de niños mexicanos con obesidad, antes y después de una intervención multidimensional de seis semanas de duración. MÉTODOS: Se tomaron muestras de sangre y de heces y se realizaron las mediciones antropométricas de seis niños con obesidad, antes y después de la intervención. La intervención consistió en modelar una dieta hipoenergética y dar recomendaciones nutricias y de actividad física. A partir del DNA de las muestras de heces se realizó la caracterización de la microbiota intestinal por secuenciación del gen 16S del RNAr. RESULTADOS: La disminución de la circunferencia de cintura se asoció con un aumento en la abundancia del género Odoribacter. Sin embargo, no se encontraron cambios en la composición de la microbiota intestinal. CONCLUSIONES: A pesar de que la intervención no modificó el índice de masa corporal, masa grasa, composición ni diversidad de la microbiota intestinal, sí se logró asociar la reducción de la circunferencia de cintura con la abundancia de Odoribacter en el presente estudio piloto en niños mexicanos con obesidad.
Subject(s)
Gastrointestinal Microbiome , Child , Humans , Gastrointestinal Microbiome/genetics , Pilot Projects , RNA, Ribosomal, 16S/genetics , Obesity , Diet , ExerciseABSTRACT
Abstract Background: Gut microbiota is a complex organized collection of microorganisms that confers multiple metabolic advantages to the host. The reduced diversity and proportion of specific gut microbial species have been associated with obesity and metabolic disorders. Multidimensional interventions, including modifications in dietary and physical activity habits, are associated with favorable changes in microbiota composition. This pilot study aimed to evaluate changes in the gut microbiota composition of Mexican children with obesity before and after a 6-week multidimensional intervention. Methods: Blood and stool samples were collected, and anthropometric measurements were obtained from six children with obesity before and after the intervention. The intervention consisted of modeling a hypo energetic diet and giving nutritional and physical activation recommendations. DNA from stool samples was used to characterize gut microbial composition by sequencing the 16S rRNA gene. Results: The decrease in waist circumference was associated with increased Odoribacter relative abundance. However, gut microbiota composition and diversity remained unchanged. Conclusions: Although no modifications in the body mass index, body fat, composition, or diversity of the gut microbiota were observed with the intervention, it was possible to associate the reduction in waist circumference with the presence of Odoribacter after a multidimensional intervention in Mexican children with obesity.
Resumen Introducción: La microbiota intestinal es un conjunto de microorganismos organizados de forma compleja que confieren múltiples ventajas metabólicas al hospedero. La reducida diversidad y la proporción de ciertas especies sobre otras se ha asociado con obesidad y enfermedades metabólicas. Las intervenciones multidimensionales, que incluyen modificaciones en los hábitos alimentarios y de actividad física, se asocian con cambios favorables en la composición de la microbiota. El objetivo de este estudio piloto fue evaluar la composición de la microbiota intestinal de niños mexicanos con obesidad, antes y después de una intervención multidimensional de seis semanas de duración. Métodos: Se tomaron muestras de sangre y de heces y se realizaron las mediciones antropométricas de seis niños con obesidad, antes y después de la intervención. La intervención consistió en modelar una dieta hipoenergética y dar recomendaciones nutricias y de actividad física. A partir del DNA de las muestras de heces se realizó la caracterización de la microbiota intestinal por secuenciación del gen 16S del RNAr. Resultados: La disminución de la circunferencia de cintura se asoció con un aumento en la abundancia del género Odoribacter. Sin embargo, no se encontraron cambios en la composición de la microbiota intestinal. Conclusiones: A pesar de que la intervención no modificó el índice de masa corporal, masa grasa, composición ni diversidad de la microbiota intestinal, sí se logró asociar la reducción de la circunferencia de cintura con la abundancia de Odoribacter en el presente estudio piloto en niños mexicanos con obesidad.
