OBJETIVO: Investigar a associação entre polimorfismos nos genes que codificam enzimas envolvidas no metabolismo da homocisteína dependente de folato e vitamina B12 e aborto espontâneo recorrente.MÉTODOS: Investigamos os polimorfismos C677T e A1298C no gene methilenotetrahidrofalato redutase (MTHFR); o polimorfismo A2756G no gene metionina sintase (MS) e a inserção 844ins68 no gene da cistationina beta-sintetase (CBS). A técnica de PCR seguido por RFLP foi utilizada para investigar os polimorfismos. Os níveis séricos de homocisteína, vitamina B12 e de folato foram investigados pela técnica de quimioluminescência. O Software Epi Info versão 6.04 foi utilizado para realizar a análise estatística. As variáveis paramétricas foram comparadas pelo teste t de Student e as variáveis não paramétricas pelo teste de Wilcoxon rank sum.RESULTADOS: As frequências dos polimorfismos gênicos em 89 mulheres com história de aborto recorrente idiopático e 150 controles foram de 19,1 e 19,6% para o C677T; 20,8 e 26% para o A1298C; 14,2 e 21,9% para o A2756G e 16,4 e 18% para a inserção 844ins68, respectivamente. Não houve diferenças significantes entre os grupos caso e controle em todos os polimorfismos dos genes investigados. No entanto, a frequência da inserção 844ins68 no gene CBS foi maior entre mulher com histórico de perdas no terceiro trimestre da gravidez p=0.003). Os níveis de homocisteína, vitamina B12 e folato séricos não foram diferentes entre os polimorfismos estudados nos grupos casos e controles. No entanto, a análise de regressão linear mostrou dependência dos níveis séricos de folato na manutenção dos níveis de homocisteína.CONCLUSÃO: Os polimorfismos gênicos investigados, assim como homocisteína, vitamina B12 e os níveis séricos de folato não foram associados com abortos recorrentes idiopático no presente estudo. Novas investigações devem ser realizados a fim de confirmar o papel da inserção 844ins68-CBS nos abortos recorrentes.

PURPOSE: To investigate the association between polymorphisms in genes that encode enzymes involved in folate- and vitamin B12-dependent homocysteine metabolism and recurrent spontaneous abortion (RSA).METHODS: We investigated the C677T and A1298C polymorphisms of the methylenetetrahydrofalate reductase gene (MTHFR), the A2756G polymorphism of the methionine synthase gene (MS) and the 844ins68 insertion of the cystathionine beta synthetase gene (CBS). The PCR technique followed by RFLP was used to assess the polymorphisms; the serum levels of homocysteine, vitamin B12 and folate were investigated by chemiluminescence. The EPI Info Software version 6.04 was used for statistical analysis. Parametric variables were compared by Student's t-test and nonparametric variables by the Wilcoxon rank sum test.RESULTS: The frequencies of gene polymorphisms in 89 women with a history of idiopathic recurrent miscarriage and 150 controls were 19.1 and 19.6% for the C677T, insertion, 20.8 and 26% for the A1298C insertion, 14.2 and 21.9% for the A2756G insertion, and 16.4 and 18% for the 844ins68 insertion, respectively. There were no significant differences between case and control groups in any of the gene polymorphisms investigated. However, the frequency of the 844ins68 insertion in the CBS gene was higher among women with a history of loss during the third trimester of pregnancy (p=0.003). Serum homocysteine, vitamin B12 and folate levels id not differ between the polymorphisms studied in the case and control groups. However, linear regression analysis showed a dependence of serum folate levels on the maintenance of tHcy levels.CONCLUSION: The investigated gene polymorphisms and serum homocysteine, vitamin B12 and folate levels were not associated with idiopathic recurrent miscarriage in the present study. Further investigations are needed in order to confirm the role of the CBS 844ins68 insertion in recurrent miscarriage.

The Klotho protein, whose gene has predominant renal expression, acts in the control of serum phosphorus and 1,25-dihydroxyvitamin D3 and regulates the function of ion channels. It also participates in the mechanism of protection against oxidative stress and acts on the vascular endothelium by inducing the production of nitric oxide. Mutations that reflect defects in the Klotho gene expression may be implicated in the onset of osteonecrosis, priapism, and leg ulcers in patients with sickle cell disease, as a result of oxidative stress and endothelial impairment, important factors in the development and severity of this disease. Previous reports regarding the association of Klotho single nucleotide polymorphisms with sickle cell disease subphenotypes have found that these polymorphisms are important to identify genetic markers of risk in these individuals and allow early and more effective therapeutic intervention.

Objective: The aim of the present study was to characterize sickle cell disease retinopathy in children and teenagers from Bahia, the state in northeastern Brazil with the highest incidence and prevalence of sickle cell disease. Methods: A group of 51 sickle cell disease patients (36 hemoglobin SS and 15 hemoglobin SC) with ages ranging from 4 to 18 years was studied. Ophthalmological examinations were performed in all patients. Moreover, a fluorescein angiography was also performed in over 10-year-old patients. Results: The most common ocular lesions were vascular tortuosity, which was found in nine (25%) hemoglobin SS patients, and black sunburst, in three (20%) hemoglobin SC patients. Peripheral arterial closure was observed in five (13.9%) hemoglobin SS patients and in three (13.3%) hemoglobin SC patients. Arteriovenous anastomoses were present in six (16.5%) hemoglobin SS patients and six (37.5%) hemoglobin SC patients. Neovascularization was not identified in any of the patients. Conclusions: This study supports the use of early ophthalmological examinations in young sickle cell disease patients to prevent the progression of retinopathy to severe disease and further blindness.

Methylenetetrahydrofolate reductase (MTHFR: EC 1.5.1.20) polymorphisms are associated to acute lymphoid leukemia in different populations. We used the polymerase chain reaction and the restriction fragment length polymorphism method (PCR-RFLP) to investigate MTHFR C677T and A1298C polymorphism frequencies in 67 patients with chronic myeloid leukemia (CML), 27 with acute myeloid leukemia FAB subtype M3 (AML-M3) and 100 apparently healthy controls. The MTHFR mutant allele frequencies were as follows: CML = 17.2% for C677T, 21.6% for A1298C; AML-M3 = 22.2% for C677T, 24.1% for A1298C; and controls = 20.5% for C677T, 21% for A1298C. Taken together, our results provide evidence that MTHFR polymorphisms have no influence on the development of CML or AML-M3.