Neonatal screening for alpha-thalassemia in southern Taiwan.

Screening peripheral or cord blood from newborn infants has been used for early detection of alpha-thalassemia conditions. The level of hemoglobin Bart's (Hb Bart's) in the blood correlates with the degree of alpha-gene deletion. Hence, the degree of gene deletion in an alpha-thalassemia carrier state can be estimated. Two thousand cord blood samples collected from the Tainan area were screened with cellulose acetate membrane electrophoresis for Hb Bart's. Ninety-nine of the 2,000 samples (4.95%) were positive for Hb Bart's. Concentrations of Hb Bart's varied from 3.2% to 30.7%. Of the 99 cases with Hb Bart's, 22 had Hb Bart's levels of 3.0% to 9.9%; 54 had Hb Bart's levels of 10.0% to 19.9%; and 23 had Hb Bart's levels of 20% to 40%. Routine cord blood screening by hemoglobin electrophoresis is recommended.