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Cystic fibrosis newborn screening was implemented in Brazil by the Public Health System in 2012. Because of cost, only 1 mutation was tested - p.Phe508del. We developed a robust low-cost genetic test for screening 11 CFTR gene mutations with potential use in developing countries.

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Abstract The collection of dried blood spots (DBSs) on filter paper has been a powerful tool in newborn screening (NBS) programs and in other fields. However, filter paper has been associated with some level of imprecision due to the filter paper matrix effect. In order to minimize measurement variations, these interferences should be evaluated by NBS assays. The aim of this study is to evaluate the performance of genetic screening processor (GSP) equipment in comparison with a widely used AutoDELFIA and to discuss the limitations and advantages of this new technology in NBS. We evaluated the performance of 3 NBS assays in DBS using GSP in comparison with AutoDELFIA. To determine the inaccuracy and the intra-assay precision, a comparative study and a replication experiment were performed. In the comparative study, human thyroid-stimulating hormone (hTSH) assay showed the highest correlation coefficient, followed by 17α-OH-progesterone and immunoreactive trypsinogen (IRT) assays. The results of the present study suggest that the GSP equipment and kits are suitable for implementation and have acceptable performance for NBS routine. Genetic screening processor assay tends to underestimate hTSH and IRT concentrations in the clinically relevant range when compared to AutoDELFIA assays. More studies are necessary to reevaluate cutoff values. Furthermore, the equipment has advantages when compared with AutoDELFIA, such as methodology with more specificity, reduction in the processing time, and randomized routine. This helps promoting faster dynamic technical processes and faster report generation.

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Mucopolysaccharidosis type II (MPS II) is a lysosomal storage disorder caused by deficiency of the enzyme iduronate-2-sulfatase, responsible for the degradation of glycosaminoglycans dermatan and heparan sulfate. Once the generation of free radicals is involved in the pathogenesis of many diseases, including some inborn errors of metabolism, the aim of this study was to evaluate blood oxidative stress parameters in MPS II patients, before and during 6 months of enzyme replacement therapy. We found significantly increased levels of malondialdehyde and carbonyl groups in plasma as well as erythrocyte catalase activity in patients before treatment compared to the control group. Plasma sulfhydryl group content and total antioxidant status were significantly reduced before treatment, while superoxide dismutase enzyme was not altered at this time when compared to controls. During enzyme replacement therapy, there was a significant reduction in levels of malondialdehyde when compared to pretreatment. Sulfhydryl groups were significantly increased until three months of treatment in MPS II patients in comparison to pretreatment. There were no significant alterations in plasma total antioxidant status and carbonyl groups as well as in catalase and superoxide dismutase activities during treatment in relation to pretreatment. The results indicate that MPS II patients are subject to lipid and protein oxidative damage and present reduction in non-enzymatic antioxidants, suggesting a possible involvement of free radicals in the pathophysiology of this disease. Also, the results may suggest that enzyme replacement therapy seems to protect against lipid peroxidation and protein damage in these patients.

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Mucopolysaccharidosis type II (MPS II) is an X-linked recessive disease caused by deficiency of the lysosomal enzyme iduronate-2-sulfatase, leading to progressive accumulation of glycosaminoglycans in nearly all cell types, tissues and organs. Enzyme replacement therapy reduces the storage of these substances in the lysosomes. Oxidative stress is related to the pathophysiology of many disorders, including inborn errors of metabolism. Oxidative damage to protein and lipid has been described in MPS types I and III. The aim of this study was to analyze DNA damage, as determined by the alkaline comet assay using silver staining, in peripheral leukocytes from MPS II patients before treatment and during the first six months of enzyme replacement therapy. We also correlated DNA damage with lipid and protein oxidative damages, analyzed by plasma malondialdehyde levels and carbonyl group content, respectively. We found a significant increase in lipid and protein damage in MPS II patients before treatment when compared to controls. Also, our results showed greater DNA damage in terms of damage index (DI) in pretreatment MPS II patients (DI=18.0 ± 2.4) when compared to controls (DI=66.0 ± 2.0). Enzyme replacement therapy led to a significant decrease in levels of malondialdehyde and DNA damage when compared to pretreatment, but did not reach control values. Significant positive correlations between DNA damage and malondialdehyde levels, as well as carbonyl group content, were observed. Our findings indicate that MPS II patients are subject to DNA damage and that enzyme replacement therapy is able to protect against this process.

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Alpha thalassemia has not been systematically investigated in Brazil. In this study, 493 unrelated individuals from the southernmost Brazilian state of Rio Grande do Sul were screened for deletional forms of α-thalassemia. One hundred and one individuals had microcytic anemia (MCV < 80 fL) and a normal hemoglobin pattern (Hb A (2) < 3.5% and Hb F < 1%). The subjects were screened for - α(3.7) , - α(4.2) , - α(20.5) , - (SEA) and - (MED) deletions but only the - α(3.7) allele was detected. The - α(3.7) allele frequency in Brazilians of European and African ancestry was 0.02 and 0.12, respectively, whereas in individuals with microcytosis the frequency was 0.20. The prevalence of α-thalassemia was significantly higher in individuals with microcytosis than in healthy individuals (p = 0.001), regardless of their ethnic origin. There were also significant differences in the hematological parameters of individuals with - α(3.7) / αα, - α(3.7) /- α(3.7) and ß-thalassemia trait compared to healthy subjects. These data suggest that α-thalassemia is an important cause of microcytosis and mild anemia in Brazilians.

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Alpha thalassemia has not been systematically investigated in Brazil. In this study, 493 unrelated individuals from the southernmost Brazilian state of Rio Grande do Sul were screened for deletional forms of α-thalassemia. One hundred and one individuals had microcytic anemia (MCV < 80 fL) and a normal hemoglobin pattern (Hb A2 < 3.5 percent and Hb F < 1 percent). The subjects were screened for -α3.7,-α4.2,-α20.5, -SEA and -MED deletions but only the -α3.7 allele was detected. The -α3.7 allele frequency in Brazilians of European and African ancestry was 0.02 and 0.12, respectively, whereas in individuals with microcytosis the frequency was 0.20. The prevalence of α-thalassemia was significantly higher in individuals with microcytosis than in healthy individuals (p = 0.001), regardless of their ethnic origin. There were also significant differences in the hematological parameters of individuals with -α3.7/αα, -α3.7/α3.7 and β-thalassemia trait compared to healthy subjects. These data suggest that α-thalassemia is an important cause of microcytosis and mild anemia in Brazilians.

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