Molecular mechanisms of thalassemia in southeast Asia.
Southeast Asian J Trop Med Public Health
;
1995 ; 26 Suppl 1(): 235-40
Artículo
en Inglés
| IMSEAR
| ID: sea-30959
ABSTRACT
Hemoglobinopathies are the most common genetic disorders in Southeast Asia. alpha-Thalassemia is most often due to a alpha-globin gene deletion. Hb Constant Spring (CS) occurs from the mutation at the termination codon of the alpha-globin gene resulting in an elongated polypeptide; alpha(CS)-globin mRNA is also unstable and only small amounts of Hb CS are produced. Thus Hb CS has an alpha-thalassemia 2-like effect. beta-Thalassemia results from a variety of molecular mechanisms, most of which are single base substitutions or deletions or insertions of one to four nucleotides. Hemoglobin E occurs from a Glu --> Lys substitution at position 26 of the beta-globin chain. The abnormal gene also results in reduced amounts of beta E-mRNA and hence of beta E-globin chains. Therefore, Hb E has a mild beta + thalassemia phenotype. Homozygous beta-thalassemia and beta-thalassemia/Hb E are the major beta-thalassemic syndromes in Southeast Asia. In spite of seemingly identical genotypes, severity of beta-thalassemia/Hb E patients can vary greatly. Some may have a severe clinical disorder approaching that seen in homozygous beta-thalassemia. A number of genetic factors have been shown to determine the differences in severity of anemia in beta-thalassemia/Hb E, including co-inheritance of alpha-thalassemia determinants and co-inheritance of other determinants which elevate Hb F expression. A correlation between the extent of beta E-globin mRNA cryptic splicing and the severity of anemia in beta(zero)-thalassemia/Hb E patients has been observed. Complete characterization of mutations causing hemoglobinopathies will help to bolster the establishment of prenatal diagnosis of these genetic disorders in the region.
Texto completo:
Disponible
Índice:
IMSEAR (Asia Sudoriental)
Asunto principal:
Asia Sudoriental
/
Humanos
/
Hemoglobina Fetal
/
Globinas
/
Etnicidad
/
Eliminación de Secuencia
/
Mutación Puntual
/
Eliminación de Gen
/
Empalme Alternativo
/
Talasemia alfa
País/Región como asunto:
Asia
Idioma:
Inglés
Revista:
Southeast Asian J Trop Med Public Health
Año:
1995
Tipo del documento:
Artículo
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