| Each hemoglobin molecule is made up of four heme groups surrounding a globin group, forming a tetrahedral structure. |
| If two mutated b globin genes are inherited, one from each parent, the patient may be clinically categorized as either b-thalassemia intermedia or b-thalassemia major. |
| Thalassemias are characterized by impaired quantitative synthesis of globin chains. |
| The globin fraction is a protein that may constitute more than 90 percent of the total molecular weight of hemoglobin. |
| There are rare non-deletional mutations affecting a globin production, such as Hb Quong Sze and Hb Constant Spring. |
| The different types of a-thalassemia are usually the consequence of deletional mutations involving a globin gene loci. |
