Study on Molecular Epidemiology of the α‐Thalassemias in Liuzhou City, Guangxi Autonomous Region, China

Abstract

Guangxi is one of the provinces of Southern China with the highest incidence of α‐thalassemia (thal). Liuzhou is the second biggest city in Guangxi. To find out the incidence of the various α‐thal genotypes, and their distribution in the Liuzhou area, an F820 Blood Cell Analysis System was used to measure the parameters of red blood cells. A SPIFE Rapid Auto‐Electrophoresis System was used to analyze the normal and abnormal hemoglobins (Hbs). Multiplex polymerase chain reaction (mPCR) was used to detect the α‐globin genotypes. Thirty‐two (2.05%) out of 7805 young couples undergoing pre‐marriage counseling, were diagnosed as having an Hb H (β₄) disease. The study of 1228 cord blood samples revealed 138 newborn children carrying an α‐thal determinant with nine different genotypes, thus making the total incidence of α‐thal 11.24%. Among 185 cases of Hb H, 119 (64.1%) were confirmed as being deletional, and 66 cases (35.7%) nondeletional types. The severity of the Hb H diseases could be classified in the following order: α^CSα/– –^SEA (α^{Constant Spring}α/– –^{Southeast Asia}); α^{− 4.2}/– –^SEA; α^{− 3.7}/– –^SEA. Ten cases of α‐thal determinants were found in combination with β‐thal. The mPCR technique can detect all kinds of combinations of the three common large deletions (– –^SEA, α^{− 4.2} and α^{− 3.7}) accurately and conveniently.

• α‐Thalassemia (thal) epidemiology
• Hb H disease
• Multiplex polymerase chain reaction (mPCR)