Delta-thalassemia

disease condition resulting from defects in the synthesis of the gene product of HBD (&#948;-globin)

Description
Up to three percent of adult haemoglobin is made up of the &#945;2&#948;2 heterotetramer (HbA2), with the remaining typical adult haemoglobin (HbA) containing &#945; and &#946; chains instead. Defects in the &#948; gene (HBD) accordingly result in very mild disease signs compared to those of equivalent homozygous and heterozygous &#946;-globin defects. Frequently for &#948;-globin defects, however, the proximal &#946; gene is affected simultaneously, leading to the more severe phenotype of a combined &#946;/&#948; thalassaemia. See thalassemia