[Globin gene mutation is a model of genetic abnormalities].
Hemoglobin has been extensively studied as a prototype of molecular abnormality, and abnormal hemoglobins have disclosed a number of molecular pathogeneses. Genetic analysis of hemoglobin has also contributed to recent advances in molecular biology. Here, thalassemia (thal) is examined. It is a congenital type of hemolytic anemia caused by defective production of either alpha- or beta-globin due to various genetic abnormalities and is referred to as alpha- or beta-thal, respectively. beta-thal is mainly caused by a point mutation, deletion or insertion of a few nucleotides resulting in decreased transcription, inability of initiating translation, abnormal RNA processing, frameshift, premature termination and production of super unstable hemoglobins. In many cases, the amount of mRNA carrying the mutation seems to be decreased. Reduced mRNA would prevent the subsequent formation of an abnormal translational product which is unstable and deleterious to the red cell membrane. Many alpha-thal's, in contrast, have an extensive gene deletion including the alpha-globin genes. Alu reiterative sequence plays an important role in the recombination of alpha-globin gene clusters which give rise to a large deletion or alpha-thal.
Hattori
Y
Y
Department of Clinical Laboratory Science, Yamaguchi University School of Medicine, Ube.
D020087:Alu Elements; D005914:Globins / Q000235:genetics*; D006801:Humans; D009154:Mutation; D011995:Recombination, Genetic; D017085:alpha-Thalassemia / Q000235:genetics; D017086:beta-Thalassemia / Q000235:genetics
D005914:Globins