Abstract
1. A family is reported in which 2 children have unmistakable sickle cell anemia, but the mother’s red cells do not sickle; the father and a third child exhibit the typical sickle cell trait. Electrophoretic studies of the hemoglobin solution prepared from the mother’s erythrocytes demonstrated, however, the presence of a small amount (5 per cent) of type S hemoglobin. This abnormal component was identified by its mobility and by addition experiments.
2. The finding that the mother’s erythrocytes contain small quantities of S hemoglobin, but are incapable of sickling, confirms the genetic concept that sickle cell anemia will only develop when both parents transmit the gene for S hemoglobin.
3. The physico-chemical and possible medico-legal aspects of the fact that S hemoglobin is sometimes only detectable by means of electrophoresis, are discussed.
