Multiple Minisequencing Screen for Seven Southeast Asian Nondeletional -Thalassemia Mutations, Wen

-Thalassemia is the most common globin disorder in the world, and the severe forms are especially prevalent among Southeast Asians. It is a disorder of absent or reduced production of -globin chains resulting from mutations in the -globin gene cluster on chromosome 16p13.3. Most -thalassemia mutations involve deletions of one () or both ( ) -globin genes, whereas point mutations within the -globin genes (T or T) are much less frequent. Nonetheless, the number of point mutations that have been described has been steadily increasing, with 40 identified to date (1, 2). The importance of nondeletional -thalassemia muta-tions is underscored by the observation that patients with nondeletional hemoglobin (Hb) H disease (T/ ) are generally more severely affected and more likely to re