ABSTRACT
Hemoglobin was the first subject that opened new perspectives in the elucidation of pathological events at the molecular level, and although there are now many examples of human pathology caused by mutation of molecules, hemoglobin remains the most extensive and richest example in this field. The globin genes are organized in clusters of alpha- and beta-globin genes—the alpha-globin genes on the short arm of chromosome 16, and the beta-globin genes on the short arm of chromosome 11. The structure of globin genes refers to the general mosaic organization of eukaryoticgenes with exons and introns which are excised during messenger RNA (mRNA) processing. The different mutations of globin genes causing structural globin-chain abnormalities are single-point mutations, double-point mutations, nonsense mutations, point mutations, deletion and insertion mutations, fusion-gene mutations, and complex globin gene mutation. The main disorders caused by structural abnormalities of the hemoglobin molecule are: unstable hemoglobin molecule, partial or total loss of oxygen transport and increased or decreased oxygen affinity.
