Investigation of a number of rare deletional mutations in the alpha globin gene cluster

Abstract

Alpha thalassemia is one of the most common genetic diseases in the world. This disease is prevalent in various parts of the world, such as India, the Middle East, Africa, and many other countries. Several clinical conditions can result from mutations. In the condition where only one of the alpha globin genes is expressed, hemoglobin H disease (Hb H) occurs. Alpha thalassemia trait and silent carrier are milder forms of the disease, caused by the deletion of one and two alpha globin genes, respectively. Several mutations result in the deletion of alpha-globin. Seven common deletional mutations include -α4.2, -α3.7, -(α)20.5, --MED, --SEA, --Fil, and --THAI. The deletional mutations -α4.2 and -α3.7 remove only one of the alpha globin genes, while others remove both α1 and α2 globin genes from the gene cluster. Nowadays, laboratories identify these mutations using the Gap PCR method and other advanced methods. In addition to these mutations, some deletional mutations are found only in certain families or certain regions. Keywords: Alpha thalassemia, deletional mutation, globin, hydrops fetalis