Screening for alpha-thalassemia in neonates. Routine erythrocyte measurements.

Alpha-thalassemia can be diagnosed in the neonate based on the level of Bart's Hemoglobin (HbB) in cord blood. This level corresponds to the degree of alpha-gene deletion. Thus, the extent of the alpha-thalassemia carrier state can be determined. This is important for genetic counseling. Because HbB is present only until a child is six months of age, and the hematologic manifestations of the carrier state may be mild, early detection is important. This study identified a logarithmic relationship between the mean corpuscular volume (MCV) and HbB. Additionally, a discrimination level of 93.5 fL. was calculated to screen for neonates that required evaluation with hemoglobin electrophoresis to identify two- and possibly three-gene deletion alpha-thalassemia. The red blood cell indices were found not to be useful in identifying patients with a one-gene deletion alpha-thalassemia.