Screening for Hb Constant Spring in the Guangdong Province, South China, using the Sebia capillary electrophoresis system.

Hb Constant Spring [Hb CS; α142, Term→Gln (TAA>CAA in α2)] is a nondeletional α-thalassemia (α-thal) defect difficult to detect on conventional electrophoresis because of its small amount in heterozygotes. We have found that individuals with an Hb CS trait could efficiently be detected using the Sebia capillarys 2 system. In the present study, we have confirmed this method in a cohort of 23,842 individuals from Guangdong Province (South China). Hb CS was detected in 71 (0.3%) of the cases. The levels of Hb CS in heterozygotes ranged from 0.1-1.0% with an average of 0.6%. We propose the reported 0.3% as a realistic figure for the prevalence of Hb CS in South China.