The Frequency of Heterozygosity for S and C Hemoglobins in Western Pennsylvania

The frequency of AS and AC type hemoglobin was studied by hemoglobin electrophoresis in 26,882 residents of Western Pennsylvania. In the black population, the frequency of S trait was estimated at 7.4% and the frequency of C trait at 1.8%. Reasons for variation in frequency from one to another subpopulation are discussed. The frequency of S and C trait was independent of age, suggesting little or no mortality can be attributed to these traits. Sickle trait was no more common in outpatients than in the general population, suggesting little or no significant trait-associated morbidity.