Alex Silva da Cruz

A non-syndromic intellectual disability associated with a de novo microdeletion at 7q and 18p, microduplication at Xp, and 18q partial trisomy detected using chromosomal microarray analysis approach

BackgroundChromosome abnormalities that segregate with a disease phenotype can facilitate the identification of disease loci and genes. The relationship between chromosome 18 anomalies with severe intellectual disability has attracted the attention of cytogeneticists worldwide. Duplications of the X chromosome can cause intellectual disability in females with variable phenotypic effects, due in part to variations in X-inactivation patterns. Additionally, deletions of the 7qter region are associated with a range of phenotypes.ResultsWe report the first case of de novo microdeletion at 7q and 18p, 18q partial trisomy, microduplication at Xp associated to intellectual disability in a Brazilian child, presenting a normal karyotype. Karyotyping showed any chromosome alteration. Chromosomal microarray analysis detected a de novo microdeletion at 18p11.32 and 18q partial trisomy, an inherited microdeletion at 7q31.1 and a de novo microduplication at Xp22.33p21.3.ConclusionsOur report illustrates a case that presents complex genomic imbalances which may contribute to a severe clinical phenotypes. The rare and complex phenotypes have to be investigated to define the subsets and allow the phenotypes classification.

Sensibilidade da PCR na amplificação do DNA bovino em diluição seriada e mistura de amostra macho e fêmea

A mixture of bovine DNA from a male and a female Jersey (Bos taurus taurus) bred in different proportions was used to determine the sensitivity of PCR to amplify and discriminate the bovine DNA samples. Samples were obtained from the peripheral blood of a bull and a heifer and DNA was isolated using a commercial kit for extraction and purification of nucleic acids. Two primers sets were designed to flank genomic regions: one autosomal and one Y-specific. DNA samples were diluted in water to a final concentration of 4x10-14 ng. The results showed positive amplification of the samples diluted to a concentration of 4x10-10ng and 4x10-4ng for the autosomal and Y-specific regions, respectively. PCR was able to discriminate the male DNA in a mixture of 99:1 (DNA ♀: DNA ♂) heifer to bull ratio. Therefore, the PCR was successful in amplifying the bovine genome in samples containing low concentrations of DNA. Thus, PCR can be used as a sensitive and efficient tool to determine the sex of the fetus in pregnant cows, helping to promote correct and efficient animal management, sex selection, and breeding in commercial herds.

Small de novo CNVs as biomarkers of parental exposure to low doses of ionizing radiation of caesium-137

The radiological accident in Goiania in 1987 caused a trail of human contamination, animal, plant and environmental by a radionuclide. Exposure to ionizing radiation results in different types of DNA lesions. The mutagenic effects of ionizing radiation on the germline are special concern because they can endures for several generations, leading to an increase in the rate of mutations in children of irradiated parents. Thus, to evaluate the biological mechanisms of ionizing radiation in somatic and germline cells, with consequent determination of the rate mutations, is extremely important for the estimation of genetic risks. Recently it was established that Chromosomal Microarray Analysis is an important tool for detecting wide spectra of gains or losses in the human genome. Here we present the results of the effect of accidental exposure to low doses of ionizing radiation on the formation of CNVs in the progeny of a human population accidentally exposed to Caesium-137 during the radiological accident in Goiânia, Brazil.

Verificação da Qualidade de DNA Genômico Extraído de Plasma Bovino para PCR

Resumo: com o surgimento e melhoramento constante de tecnicas laboratoriais voltadas a identificacao de sexo fetal, uma das tecnicas amplamente utilizada e a da reacao em cadeia pela polimerase. Para que esta metodologia funcione corretamente e nessesarios metodologias de fornecimento de DNA de boa qualidade. O objetivo do presente estudo foi avaliar a qualidade de DNA bovino isolado de plasma Ate o momento, nao foi publicado teste semelhante para bovinos. Palavras-chave: Qualidade. DNA Genomico. Plasma bovino.