BMP6 and VDR gene polymorphisms are associated with osteonecrosis in a sickle cell anaemia cohort.

The occurrence and severity of osteonecrosis in sickle cell anaemia (SCA) vary due to risk factors, including genetic modifiers. Bone morphogenetic proteins (BMPs), particularly BMP6, and the vitamin D receptor (VDR) play key roles in cartilage and bone metabolism, making them potential contributors to orthopaedic outcomes in SCA. Here, we evaluated the association of polymorphisms in BMP6 (rs3812163, rs270393 and rs449853) and VDR (FokI rs2228570 and Cdx2 rs11568820) genes with osteonecrosis risk in a Brazilian SCA cohort. A total of 177 unrelated SCA patients were selected. The AA genotype of BMP6 rs3812163 was independently associated with a lower osteonecrosis risk (p = 0.015; odds ratio (OR): 0.38; 95% confidence interval (CI): 0.18-0.83) and with the long-term cumulative incidence of osteonecrosis (p = 0.029; hazard ratio: 0.56, 95% CI: 0.34-0.94). The VDR rs2228570 TT genotype was independently associated with a lower osteonecrosis risk (p = 0.039; OR: 0.14; 95% CI: 0.02-0.90). In summary, our results provide evidence that BMP6 rs3812163 and the VDR rs2228570 might be implicated in osteonecrosis pathophysiology in SCA and might help identify individuals at high risk.

Global analysis of erythroid cells redox status reveals the involvement of Prdx1 and Prdx2 in the severity of beta thalassemia.

ß-thalassemia is a worldwide distributed monogenic red cell disorder, characterized by an absent or reduced beta globin chain synthesis. The unbalance of alpha-gamma chain and the presence of pathological free iron promote severe oxidative damage, playing crucial a role in erythrocyte hemolysis, exacerbating ineffective erythropoiesis and decreasing the lifespan of red blood cells (RBC). Catalase, glutathione peroxidase and peroxiredoxins act together to protect RBCs from hydrogen peroxide insult. Among them, peroxiredoxins stand out for their overall abundance and reactivity. In RBCs, Prdx2 is the third most abundant protein, although Prdxs 1 and 6 isoforms are also found in lower amounts. Despite the importance of these enzymes, Prdx1 and Prdx2 may have their peroxidase activity inactivated by hyperoxidation at high hydroperoxide concentrations, which also promotes the molecular chaperone activity of these proteins. Some studies have demonstrated the importance of Prdx1 and Prdx2 for the development and maintenance of erythrocytes in hemolytic anemia. Now, we performed a global analysis comparatively evaluating the expression profile of several antioxidant enzymes and their physiological reducing agents in patients with beta thalassemia intermedia (BTI) and healthy individuals. Furthermore, increased levels of ROS were observed not only in RBC, but also in neutrophils and mononuclear cells of BTI patients. The level of transcripts and the protein content of Prx1 were increased in reticulocyte and RBCs of BTI patients and the protein content was also found to be higher when compared to beta thalassemia major (BTM), suggesting that this peroxidase could cooperate with Prx2 in the removal of H2O2. Furthermore, Prdx2 production is highly increased in RBCs of BTM patients that present high amounts of hyperoxidized species. A significant increase in the content of Trx1, Srx1 and Sod1 in RBCs of BTI patients suggested protective roles for these enzymes in BTI patients. Finally, the upregulation of Nrf2 and Keap1 transcription factors found in BTI patients may be involved in the regulation of the antioxidant enzymes analyzed in this work.

Follow-up of children with hemoglobinopathies diagnosed by the Brazilian Neonatal Screening Program in the State of Pernambuco.

OBJECTIVE: To determine the geographical distribution of hemoglobinopathies in the State of Pernambuco, to characterize the children with these diseases and to describe factors associated with their follow-up at the referral center during the period from 2003 to 2010. METHODS: A retrospective, cross-sectional, descriptive study was carried out of 275 medical records from a total of 302 children with hemoglobinopathies diagnosed by the National Neonatal Screening Program in the State of Pernambuco in the study period. Microsoft Excel was used for data processing and analysis. The chi-square and the Fisher test were used for statistical analysis. The level of significance was set at 5%. Terra View software was used to analyze the geographical distribution of hemoglobinopathies in the State. RESULTS: A total of 8.9% of the cases of hemoglobinopathies detected in the period were not followed up at the referral center. For the mothers of children with diseases, this was their second or third or more pregnancy in 64.2% and 30.2%, respectively. Regarding the influence of region of residence and regular medical appointments, the study demonstrated that children from the Zona da Mata, Sertão and Vale do São Francisco regions did not attend 45.2%, 50% and 55.6% of their appointments in the outpatient department, respectively. CONCLUSIONS: This study shows that a significant number of children do not begin consultations in the outpatient clinic and even those who started treatment early and who have the most severe form of the disease, usually miss medical appointments.

Follow-up of children with hemoglobinopathies diagnosed by the Brazilian Neonatal Screening Program in the State of Pernambuco

OBJECTIVE: To determine the geographical distribution of hemoglobinopathies in the State of Pernambuco, to characterize the children with these diseases and to describe factors associated with their follow-up at the referral center during the period from 2003 to 2010. METHODS: A retrospective, cross-sectional, descriptive study was carried out of 275 medical records from a total of 302 children with hemoglobinopathies diagnosed by the National Neonatal Screening Program in the State of Pernambuco in the study period. Microsoft Excel was used for data processing and analysis. The chi-square and the Fisher test were used for statistical analysis. The level of significance was set at 5%. Terra View software was used to analyze the geographical distribution of hemoglobinopathies in the State. RESULTS: A total of 8.9% of the cases of hemoglobinopathies detected in the period were not followed up at the referral center. For the mothers of children with diseases, this was their second or third or more pregnancy in 64.2% and 30.2%, respectively. Regarding the influence of region of residence and regular medical appointments, the study demonstrated that children from the Zona da Mata, Sertão and Vale do São Francisco regions did not attend 45.2%, 50% and 55.6% of their appointments in the outpatient department, respectively. CONCLUSIONS: This study shows that a significant number of children do not begin consultations in the outpatient clinic and even those who started treatment early and who have the most severe form of the disease, usually miss medical appointments...

[Prevalence of dyslipidemia in middle-aged adults with NOS3 gene polymorphism and low cardiorespiratory fitness]. / Prevalência de dislipidemia em adultos de meia-idade com polimorfismo do gene NOS3 e baixa aptidão cardiorrespiratória.

OBJECTIVE: To evaluate the influence of the interaction between endothelial nitric oxide synthase gene (NOS3) polymorphisms at positions -786T>C, Glu298Asp and intron 4b/a, and cardiorespiratory fitness on plasma nitrite/nitrate levels, blood pressure, lipid profile, and prevalence of cardiometabolic disorders. SUBJECTS AND METHODS: Ninety-two volunteers were genotyped for NOS3 polymorphisms at positions (-786T>C and Glu298Asp) and (intron 4b/a) and divided according to the genotype: non-polymorphic (NP) and polymorphic (P). After that, they were subdivided according to the cardiorespiratory fitness associated with genotype: high (HNP and HP) and low (LNP and LP). RESULTS: The subjects with polymorphism for the interactions at positions Glu298Asp + intron 4b/a, and Glu298Asp+-786T>C showed the highest values in total cholesterol, as well as dyslipidemia. CONCLUSION: Our findings show that NOS3 gene polymorphisms at positions -786T>C, Glu298Asp, and intron 4b/a exert negative effects on the lipid profile compared with those who do not carry polymorphisms.

Prevalência de dislipidemia em adultos de meia-idade com polimorfismo do gene NOS3 e baixa aptidão cardiorrespiratória / Prevalence of dyslipidemia in middle-aged adults with NOS3 gene polymorphism and low cardiorespiratory fitness

OBJETIVO: Analisar a influência da associação dos polimorfismos do gene da sintase do óxido nítrico endotelial (NOS3) para as posições -786T>C, Glu298Asp e íntron 4b/a e a aptidão cardiorrespiratória sobre as concentrações de nitrito/nitrato, pressão arterial, perfil lipídico e prevalência de doenças cardiometabólicas em adultos. SUJEITOS E MÉTODOS: Noventa e duas pessoas foram divididas de acordo com o genótipo: não polimórficas (NP) e polimórficas (P). Posteriormente, foram subdivididas pela aptidão cardiorrespiratória associada ao genótipo: alta (ANP e AP) ou baixa (BNP e BP). RESULTADOS: Os indivíduos que apresentavam polimorfismo para as posições Glu298Asp+Íntron 4b/a e Glu298Asp+-786T>C e baixa aptidão cardiorrespiratória apresentaram maiores valores de colesterol total e maior prevalência de dislipidemia. CONCLUSÃO: Nossos dados demonstram que os polimorfismos do gene da NOS3 para essas duas associações influenciam os níveis de colesterol plasmático, e essa associação foi mais claramente observada quando os indivíduos apresentavam menor nível de aptidão cardiorrespiratória.

OBJECTIVE: To evaluate the influence of the interaction between endothelial nitric oxide synthase gene (NOS3) polymorphisms at positions -786T>C, Glu298Asp and intron 4b/a, and cardiorespiratory fitness on plasma nitrite/nitrate levels, blood pressure, lipid profile, and prevalence of cardiometabolic disorders. SUBJECTS AND METHODS: Ninety-two volunteers were genotyped for NOS3 polymorphisms at positions (-786T>C and Glu298Asp) and (intron 4b/a) and divided according to the genotype: non-polymorphic (NP) and polymorphic (P). After that, they were subdivided according to the cardiorespiratory fitness associated with genotype: high (HNP and HP) and low (LNP and LP). RESULTS: The subjects with polymorphism for the interactions at positions Glu298Asp + intron 4b/a, and Glu298Asp+-786T>C showed the highest values in total cholesterol, as well as dyslipidemia. CONCLUSION: Our findings show that NOS3 gene polymorphisms at positions -786T>C, Glu298Asp, and intron 4b/a exert negative effects on the lipid profile compared with those who do not carry polymorphisms.

MTHFR polymorphic variant C677T is associated to vascular complications in sickle-cell disease.

Vaso-occlusion is a determinant for most signs and symptoms of sickle-cell anemia (SCA). The mechanisms involved in the pathogenesis of vascular complications in SCA remain unclear. It is known that genetic polymorphisms associated with thrombophilia may be potential modifiers of clinical features of SCA. The genetic polymorphisms C677T and A1298C relating to the enzyme methylenetetrahydrofolate reductase (MTHFR), a clotting Factor V Leiden mutation (1691G→A substitution of Factor V Leiden), and the mutant prothrombin 20210A allele were analyzed in this study. The aim was to find possible correlations with vascular complications and thrombophilia markers in a group of SCA patients in Pernambuco, Brazil. The study included 277 SCA patients, divided into two groups: one consisting of 177 nonconsanguineous SCA patients who presented vascular manifestations of stroke, avascular necrosis, leg ulcers, priapism, and acute chest syndrome (group 1); and the other consisting of 100 SCA patients without any reported vascular complication (group 2). Molecular tests were done using either polymerase chain reaction (PCR) restriction fragment length polymorphism or allele-specific PCR techniques. Comparisons between the groups were made using the χ(2) test. The 677 CT and TT genotypes showed a significant risk of vascular complications (p=0.015). No significant associations between the groups were found when samples were analyzed for the MTHFR A1298C allele (p=0.913), Factor V G1691 (p=0.555), or prothrombin G20210A mutation (p=1.000). The polymorphism MTHFR C677T seemed to be possibly predictive for the development of some vascular complications in SCA patients among this population.

Women with TT genotype for eNOS gene are more responsive in lowering blood pressure in response to exercise.

INTRODUCTION: The aim of this study was to investigate whether -786T>C endothelial nitric oxide synthase (eNOS) gene polymorphism might influence the effect of long-term exercise training (ET) on the blood pressure and its relationship with NO production in healthy postmenopausal women. DESIGN: Longitudinal study. METHOD: Fifty-five postmenopausal women were studied in a double-blinded design. ET was performed for 3 days a week, each session consisting of 60 min during 6 months, in an intensity of 50-70% VO2max. After that, eNOS genotype analysis was performed and women were divided into two groups: TC+CC (n=41) and TT (n=14) genotype. RESULTS: No changes were found in the anthropometric parameters after ET in both the groups. Systolic and diastolic BP values were significantly reduced in both the groups, but women with TT genotype were more responsive in lowering BP as compared with those with TC+CC genotype. Plasma nitrite/nitrate concentrations were similar at baseline in both the groups, but the magnitude of increment in NO production in response to ET was higher in women with TT genotype as compared with those with TC+CC genotype. CONCLUSION: Our study shows clearly that women with or without eNOS gene polymorphism had no differences in NO production at basal conditions, but when physical exercise is applied an evident difference is detected showing that the presence of -786T>C eNOS gene polymorphism had a significant impact in the health-promoting effect of aerobic physical training on the blood pressure in postmenopausal women.

Molecular variations linked to the grouping of beta- and alpha-globin genes in neonatal patients with sickle cell disease in the State of Pernambuco, Brazil.

Various factors have been described as phenotypic modulators of sickle cell disease, such as levels of fetal hemoglobin (Hb F), presence of alpha-thalassemia (thal), and haplotypes of the beta-globin genes. In order to characterize and determine the frequency of the betaS and betaC mutations and the prevalence of -alpha3.7-thal, 74 patients with sickle cell disease detected during neonatal screening in the State of Pernambuco, Brazil, were studied. The haplotypes of the beta gene and -alpha3.7-thal were determined using polymerase chain reaction (PCR), and specific restriction endonucleases were used to establish the polymorphic sites of the haplotypes. The results showed the high frequency of the Central African Republic (CAR) or Bantu haplotype in the State of Pernambuco, Brazil. The low frequency of the Benin haplotype recorded in this study, in comparison with other states in northeast Brazil, suggests the diversity of origins of Afro-Brazilians in this region.