Influence of hemoglobin phenotype on the mean erythrocyte volume.

The influence of the hemoglobin (Hgb) phenotype on mean erythrocyte volume was re-examined in the light of recent evidence indicating a poor correlation between manual and more precise automated methods of measurement. The present studies identified a 17.6% frequency of microcytosis in a population of nonanemic Black males, a value higher than previously appreciated. In addition, it was shown that the frequency of microcytosis was also a function of the Hgb phenotype. Thus, 9.4% of Hgb AA, 18.6% of AS and 26.5% of AC subjects had microcytic erythrocytes. The data presented are consistent with the hypothesis that both the alpha-gene complement and the beta-chain phenotype contribute to the erythrocytic mean corpuscular volume and that the frequency of microcytosis in a patient population is a function of both of these variables.