ABSTRACT
We report the clinical and laboratory findings concerning three unrelated Brazilian patients investigated for polycythemia, whose definitive diagnosis could only be established after the presence of Hb Coimbra (b99 Asp ® Glu) was demonstrated. This illustrates the importance of properly investigating hereditary hemoglobinopathies in cases of erythrocytosis because in some populations variants with high oxygen affinity may be more frequent than expected but go undetected when conventional electrophoresis is used as the sole detection procedure.
Subject(s)
Humans , Male , Female , Adolescent , Middle Aged , Hemoglobins, Abnormal/genetics , Polycythemia/diagnosis , Anemia, Hypochromic/congenital , Brazil , Electrophoresis , Globins , Polycythemia/blood , Toxoplasmosis, CongenitalABSTRACT
CONTEXT: We verified molecular alterations in a 72-year-old Brazilian male patient with a clinical course of homozygous beta-thalassemia intermedia, who had undergone splenectomy and was surviving without regular blood transfusions. The blood cell count revealed microcytic and hypochromic anemia (hemoglobin = 6.5 g/dl, mean cell volume = 74 fl, mean cell hemoglobin = 24 pg) and hemoglobin electrophoresis showed fetal hemoglobin = 1.3 percent, hemoglobin A2 = 6.78 percent and hemoglobin A = 79.4 percent. OBJECTIVE: To identify mutations in a patient with the symptoms of beta-thalassemia intermedia. DESIGN: Molecular inquiry into the mutations possibly responsible for the clinical picture described. SETTING: The structural molecular biology and genetic engineering center of the Universidade Estadual de Campinas, Campinas, Brazil. PROCEDURES: DNA extraction was performed on the patient's blood samples. The polymerase chain reaction (PCR) was done using five specific primers that amplified exons and the promoter region of the beta globin gene. The samples were sequenced and then analyzed via computer programs. RESULTS: Two mutations that cause the disease were found: -101 (C > T) and codon 39 (C > T). CONCLUSIONS: This case represents the first description of 101 (C > T) mutation in a Brazilian population and it is associated with a benign clinical course
Subject(s)
Humans , Male , Aged , Globins , Point Mutation , beta-Thalassemia , Codon , Polymerase Chain ReactionABSTRACT
Os recentes avanços laboratoriais da biologia molecular permitiram o estudo de novos marcadores genéticos. No presente trabalho, investigamos a epidemiologia molecular da variante A- da deficiência de G-6-PD em uma populaçäo do estado de Säo Paulo. Material e métodos: Foram analisados molecularmente 60 homens paulistas näo-consangüineos (50 caucasóides e 10 negroídes), portadores da variante A- de G-6-PD. A caracterizaçäo molecular foi realizada pela digestäo dos exons 3 e 4 do gene da G-6-PD com a enzima de restriçäo NLa III. Resultados: Todos os indivíduos analisados revelaram a presença da mutaçäo A- 202 (G A). Discussäo: A populaçäo paulista é caracterizada por um alto grau de miscigenaçäo entre descendentes de europeus, principalmente de origens portuguesa, italiana e espanhola, e indivíduos de origem africana. Apesar dessa heterogenidade étnica, a mutaçäo A-202 (G A) foi a única introduzida nessa populaçäo. Esse resultado está de acordo com fluxo gênico no passado da variante A- de G-6-PD da Africa para a Europa. Conclusäo: Nossoa resultados indicam que a variante A- de G-6-PD está associada exclusivamente com a mutaçäo 202 (G A) no estado de Säo