Box Haemoglobinopathies

The haemoglobinopathies are inherited disorders affecting the structure or synthesis of haemoglobin. They are remarkably common, with an estimated 7% of the world population being carriers (Weatherall 2000). Haemoglobinopathies in clude structural variants of haemoglobin such as sickle haemoglobin (Hb S) and disorders in which the synthesis of one or more globin molecules is reduced or absent (the thalassaemias) (Weatherall 2001).

Figure 1.1 Genes encoding haemoglobin. Haemoglobin is a tetrameric molecule comprised of two pairs of identical polypeptides encoded by genes in the a globin and ß globin gene clusters on chromosomes 16 and 11, respectively. Fetal haemoglobin (Hb F) (a2y2) comprises two a globin chains and two y globin chains; after birth this is replaced by adult Hb A (a2ß2) and very small amounts of Hb A2 (a282). In Hb S (a2ßS2), the ß globin polypeptide encoded by the HBB gene contains a glutamine to valine substitution.

Figure 1.1 Genes encoding haemoglobin. Haemoglobin is a tetrameric molecule comprised of two pairs of identical polypeptides encoded by genes in the a globin and ß globin gene clusters on chromosomes 16 and 11, respectively. Fetal haemoglobin (Hb F) (a2y2) comprises two a globin chains and two y globin chains; after birth this is replaced by adult Hb A (a2ß2) and very small amounts of Hb A2 (a282). In Hb S (a2ßS2), the ß globin polypeptide encoded by the HBB gene contains a glutamine to valine substitution.

and its implications for disease, has led to a succession of remarkable discoveries that have been a paradigm for much of our current understanding of human genetics. It has been a treasure trove of discovery to which many investigators have devoted their scientific careers, an investment in detailed research which has been repaid many times over and continues to reveal new discoveries to this day.

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