Clinical Characteristics of Heterozygote and Double Heterozygote of Three Rare Mutations in alpha-Thalassemia

Objective:To examine clinical characteristics of heterozygote and double heterozygote of three rare mutations [Hb Constants Spring(Hb CS),Hb Westmead(Hb WS) and Hb Quong Sze(Hb QS)] among alpha-thalassemia patients in Guangxi province, China. Methods:135 alpha-thalassemia patients, and 40 controls, were included in this study. Routine examination of blood and hemoglobin electrophoresis were performed. The alpha-thalassemia mutations were detected using Gap-PCR and reverse dot-blotting. Results: There were no clinical symptoms in three heterozygote groups and the double heterozygote group of αCSα/αWSα. MCV and MCH in the heterozygote group of Hb QS were significantly lower than those in other heterozygote groups(Hb CS and Hb WS)(P0.05). However,there was mild clinical symptoms in the double heterozygote group of αCSα/αQSα, while MCV and MCH were also significantly lower than those in other heterozygote groups(Hb CS and Hb WS)(P 0.05). Conclusions: The heterozygote Hb CS,heterozygote Hb WS and double heterozygote αCSα/αWSα are the silent carrier in clinical manifestations, the heterozygote Hb QS is the thalassemia trait, and the double heterozygote αCSα/αQSα is similar to the HbH disease. It is important to note this variability of clinical manifestations of those double heterozygotes in genetic consultation.