Charache S, Joffe A, Wong H
J Adolesc Health Care. 1987 Jul;8(4):315-21. doi: 10.1016/0197-0070(87)90001-5.
A group of black adolescents stratified by age and sexual maturity (Tanner stage) had electronic blood counts determined. Hemoglobin, hematocrit, and red cell count were lower than the means reported for white or Hispanic children of the same age. The difference could not be explained by iron deficiency, but the data were insufficient to exclude alpha thalassemia as a cause.