Globin Genes: Polymorphic Variants and Mutations

Abstract

Abstract The globin genes encode the globin chains that make up hemoglobin (Hb). More than 1000 polymorphic variants of the globin genes have been characterized, consisting of single nucleotide substitutions through to complex gene rearrangements. Most globin gene mutations either alter the amino acid sequence of a globin chain, creating an abnormal hemoglobin such as Hb S, or cause a reduction in the synthesis of one or more normal globin chains (the thalassemia disorders). A few mutations cause both types of defect, while others are simple natural polymorphisms that are used as DNA markers.