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Abstract(s)
As hemoglobinopatias constituem as doenças monogénicas recessivas mais frequentes a nível mundial. Resultam de alterações nos genes que regulam a síntese direta das cadeias de globina da hemoglobina. Em indivíduos normais a síntese de alfa e beta globina é regulada por 4 genes localizados nos cromossomas 16 e 2 nos cromossomas 11.
Dividem-se em dois grandes grupos, hemoglobinopatias quantitativas, quando se verifica uma alteração quantitativa na síntese de um tipo de cadeias globínicas (talassemia e persistência hereditária de hemoglobina fetal) e hemoglobinopatias qualitativas ou estruturais, quando existe uma modificação estrutural de um tipo de cadeias globínicas (caso da anemia falciforme ou drepanocitose). Estimam-se que existam cerca de 270 milhões de portadores de hemoglobinopatias e cerca de 300-500 mil casos de nascimentos de crianças com anemia falciforme e formas severas de talassemia.
Em Portugal, as hemoglobinopatias mais frequentes são a anemia falciforme, a beta-talassemia major e intermédia. Assim sendo, foi criado um programa nacional de controlo de hemoglobinopatias com o objectivo de prevenir, diagnosticar e fornecer tratamento adequado às formas graves da doença.
A deteção de portadores de hemoglobinopatias é iniciada com um hemograma e a partir dos seus resultados procede-se à análise das hemoglobinas utilizando vários métodos como a eletroforese das hemoglobinas e focagem isoelétrica e à quantificação das hemoglobinas A2 e fetal através de técnicas como HPLC (caracterização de fenótipo). No entanto, a confirmação ou caracterização do genótipo de alguns destes distúrbios só pode ser feita através de técnicas de biologia molecular.
A prevenção destas patologias assenta na deteção de possíveis portadores e respectivos cônjuges, aconselhamento genético de casais de risco e diagnóstico pré-natal.
Hemoglobinopathies are the most common recessive monogenic diseases worldwide. Result from alterations in the genes that control the direct synthesis of the globin chains of hemoglobin. In normal individuals, α and β-globin synthesis is regulated by four genes located on chromosomes 16 and two on chromosomes 11. They are divided into two large groups, quantitative hemoglobinopathies, when there is a quantitative change in the synthesis of a type of globin chains (thalassemias and hereditary persistence of fetal hemoglobin) and qualitative or structural hemoglobinopathies, when there is a structural modification of a type of globin chains (sickle cell anemia). It is estimated that there are about 270 million carriers of hemoglobinopathies and about 300-500 thousand cases of births of children with sickle cell anemia and severe forms of thalassemia. In Portugal, the most frequent and severe hemoglobinopathies are sickle-cell disease, β-thalassemia major and β-thalassemia intermedia. Therefore, a National Program for the Control of Hemoglobinopathies was created, with the aim of preventing, diagnosing and providing adequate treatment for severe forms of the disease. The detection of carriers of hemoglobinopathies begins with a blood count and from your results, the hemoglobins are studied using various methods such as hemoglobin electrophoresis and isoelectric focusing and quantification of hemoglobins A2 and Fetal, through techniques such as HPLC (phenotype characterization). However, confirmation or characterization of the genotype of some of these disorders can only be done using molecular biology techniques. The prevention of these pathologies is based on the detection of possible carriers and their spouses, genetic counseling for at-risk couples and prenatal diagnosis.
Hemoglobinopathies are the most common recessive monogenic diseases worldwide. Result from alterations in the genes that control the direct synthesis of the globin chains of hemoglobin. In normal individuals, α and β-globin synthesis is regulated by four genes located on chromosomes 16 and two on chromosomes 11. They are divided into two large groups, quantitative hemoglobinopathies, when there is a quantitative change in the synthesis of a type of globin chains (thalassemias and hereditary persistence of fetal hemoglobin) and qualitative or structural hemoglobinopathies, when there is a structural modification of a type of globin chains (sickle cell anemia). It is estimated that there are about 270 million carriers of hemoglobinopathies and about 300-500 thousand cases of births of children with sickle cell anemia and severe forms of thalassemia. In Portugal, the most frequent and severe hemoglobinopathies are sickle-cell disease, β-thalassemia major and β-thalassemia intermedia. Therefore, a National Program for the Control of Hemoglobinopathies was created, with the aim of preventing, diagnosing and providing adequate treatment for severe forms of the disease. The detection of carriers of hemoglobinopathies begins with a blood count and from your results, the hemoglobins are studied using various methods such as hemoglobin electrophoresis and isoelectric focusing and quantification of hemoglobins A2 and Fetal, through techniques such as HPLC (phenotype characterization). However, confirmation or characterization of the genotype of some of these disorders can only be done using molecular biology techniques. The prevention of these pathologies is based on the detection of possible carriers and their spouses, genetic counseling for at-risk couples and prenatal diagnosis.
Description
Tese de mestrado, Análises Clínicas, 2023, Universidade de Lisboa, Faculdade de Farmácia.
Keywords
Laboratório Bioquímica clínica Hematologia Microbiologia Hemoglobinopatias Teses de mestrado - 2023