The Role of Gene Mutations Detection in Defining the Spectrum of ß – Thalassemia in Various Ethnic Regions

The thalassemia is a widespread with about 5% of the world population affected by it and is found in some 60 countries, with the highest prevalence in the Mediterranean region, parts of North and West Africa, the Middle East, the Indian subcontinent, southern Far East and south-eastern Asia, together comprising the so-called thalassemia belt. In western countries, thalassemia affects mostly individuals whose ancestry is traceable to high prevalence areas. As an example, there are around 1,000 cases of ┚-thalassemia major in the United States, most of whom are descendants of Mediterranean, Asian Indian, South Asian or Chinese ancestors. This figure is even less than half of the number of ┚-thalassemic patients in Fars Province, a region only 120,000 km 2 large in southern Iran (Haghshenas and Zamani, 1997; Rahim et al., 2007). The gene frequency of s-thalassemia, however, is varies from area to area, having its highest rate of more than 10% around the Caspian Sea and Persian Gulf. The prevalence of the disorder in other areas is between 4-8% (Rahim and Abromand, 2008). There are many genes coding for the globins. They are found on chromosome 11 (┚-globin cluster) or chromosome 16 (┙-globin cluster) figure1.