Assuntos
Cromossomos Humanos Par 20/genética , Cromossomos Humanos Par 4/genética , Síndrome de Ellis-Van Creveld/genética , Doenças Uterinas/genética , Doenças Vaginais/genética , Adulto , Pré-Escolar , Segregação de Cromossomos , Feminino , Ligação Genética , Genótipo , Haplótipos , Humanos , Escore Lod , Masculino , Repetições de Microssatélites , Polidactilia/genética , GravidezRESUMO
Tuberous sclerosis complex (TSC) is an autosomal dominant condition whose signs and symptoms may vary from a few hypopigmented skin spots to epilepsy, severe mental retardation, and renal failure. The disease is caused by mutations in either TSC1 or TSC2 gene, at chromosome 9q34 and 16p13.3. Inactivation of both alleles at TSC1 or TSC2 loci is associated with the development of hamartomas in different organs, and only rarely with malignant neoplasms. In this study we present a 6-year-old boy with TSC and with a malignant islet cell tumor of the pancreas. Mutation analysis of DNA extracted from peripheral blood cells of the patient identified an R1459X de novo mutation in exon 33 of the TSC2 gene. Immunohistochemical analysis with anti-tuberin antibodies on paraffin-embedded tissue sections showed loss of tuberin immunostaining in tumor cells but normal expression in residual normal pancreas. DNA analysis of tumor and normal cells showed chromosome 16p13 loss of heterozygosity in malignant pancreatic islet cell tumor but not in normal pancreas. These findings suggest a role for tuberin, the TSC2 gene product, in the pathogenesis of malignant pancreatic endocrine tumor.
Assuntos
Carcinoma de Células das Ilhotas Pancreáticas/genética , Genes Supressores de Tumor/fisiologia , Neoplasias Pancreáticas/genética , Proteínas Repressoras/genética , Esclerose Tuberosa/genética , Carcinoma de Células das Ilhotas Pancreáticas/complicações , Criança , Humanos , Perda de Heterozigosidade/genética , Masculino , Mutação/genética , Neoplasias Pancreáticas/complicações , Esclerose Tuberosa/complicações , Proteína 2 do Complexo Esclerose Tuberosa , Proteínas Supressoras de TumorRESUMO
We report clinical and molecular findings in 14 patients with cleidocranial dysplasia (CCD), a well defined skeletal disorder with characteristic clinical findings and autosomal dominant inheritance. We identified ten heterozygous base changes in the RUNX2 gene, including six novel mutations [c.522insA, c.389G>A (W130X), c.662T>G (V221G), IVS2+T>A, c.1111_1129del19, and c.873_874delCA]. We did not establish a clear correlation between clinical features and genotype, the phenotypes of all patients analyzed falling within the range of variation described in CCD without an effect related to the length of the predicted protein. In two cases, however, a limb-girdle myopathy affecting the shoulder muscles was also identified. Our data add new variants to the repertoire of RUNX2 mutations in CCD.
Assuntos
Displasia Cleidocraniana/genética , Mutação , Proteínas de Neoplasias , Fatores de Transcrição/genética , Substituição de Aminoácidos/genética , Células Cultivadas , Subunidade alfa 1 de Fator de Ligação ao Core , Feminino , Fibroblastos/química , Fibroblastos/metabolismo , Mutação da Fase de Leitura/genética , Humanos , Itália , Masculino , Estudos RetrospectivosRESUMO
Oxidative stress has been proposed as a pathogenic mechanism of atherosclerosis, cell aging, and neurologic disorders in Down syndrome. This study demonstrates a systemic decrease of all glutathione forms, including glutathionyl-hemoglobin, in the blood of children with Down syndrome. Furthermore, we obtained a disequilibrium, in vivo, between the antioxidant enzyme activities.
Assuntos
Síndrome de Down/metabolismo , Glutationa Redutase/metabolismo , Glutationa Transferase/metabolismo , Glutationa/metabolismo , Superóxido Dismutase/metabolismo , Criança , Pré-Escolar , Cromatografia Líquida de Alta Pressão , Síndrome de Down/enzimologia , Feminino , Humanos , Masculino , Espécies Reativas de Oxigênio/metabolismoRESUMO
Se describe una niña que presenta las características del síndrome de Nager, que consisten principalmente en una disostosis mandibulofacial con anomalías radiales. La mayoría de los casos son esporádicos pero hay evindencias que sugieren herencia monogénica. El diagnóstico prenatal ecográfico puede ser útil.