Rare α0-thalassemia deletions detected by MLPA in five unrelated Brazilian patients

Abstract Alpha-thalassemias are among the most common genetic diseases in the world. They are characterized by hypochromic and microcytic anemia and great clinical variability, ranging from a practically asymptomatic phenotype to severe anemia, which can lead to intrauterine or early neonatal death. Deletions affecting the α-globin genes, located on chromosome 16p13.3, are the main causes of α-thalassemia. Multiplex ligation-dependent probe amplification (MLPA) can be used to detect rearrangements that cause α-thalassemia, particularly large deletions involving the whole α cluster and/or deletions in the HS-40 region. Here, MLPA was used to investigate the molecular basis of α-thalassemia in five unrelated patients, three of whom had Hb H disease. In addition to the -α3.7 deletion identified in the patients with Hb H disease, four different α0 deletions removing 15 to 225 kb DNA segments were found: two of them remove both the α genes, one affects only the regulatory element (HS-40) region, and another one extends over the entire α cluster and the HS-40 region. These results illustrate the diversity of α-thalassemia deletions in the Brazilian population and highlight the importance of molecular investigation in cases that present with microcytosis and hypochromia without iron deficiency and normal or reduced Hb A2 levels..

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.

Identificação e caracterização de variantes novas e raras da hemoglobina humana: [revisão] / Identification of characterization of novel and rare variants of human hemoglobin: [review]

As anormalidades estruturais da hemoglobina estão entre as doenças genéticas mais comumente encontradas nas populações humanas. O Laboratório de Hemoglobinopatias do Departamento de Patologia Clínica da Faculdade de Ciências Médicas da Universidade Estadual de Campinas - Unicamp, localizado em Campinas, no estado de São Paulo, região Sudeste do Brasil, realizou, em seus 27 anos de existência, cerca de 130.000 diagnósticos. Entre as variantes estruturais detectadas, as hemoglobinas S, C e D-Punjab foram, como esperado, as mais freqüentes, porém um número expressivo de outras hemoglobinas anômalas, novas e raras, também foi encontrado. Esses achados estão sumarizados no presente artigo.

Hemoglobin structural abnormalities are among the most commonly found human genetic diseases. The Laboratory of Hemoglobinopathies in the Clinical Pathology Department of the Medical Sciences School of the State University in Campinas - Unicamp, São Paulo, Southeastern Brazil, carried out, in its 27 years of activity, about 130,000 diagnoses. As expected, hemoglobins S, C and D were the most frequently observed variants, but an expressive number of other abnormal, novel and rare hemoglobins, was also detected. These findings are summarized in the present article.