Abstract
A Jewish family in which Hb L Ferrara (α247 Asp → Gly β2) occurred is reported. Studies of some of the properties of this hemoglobin demonstrated that its oxygen equilibria, number of readily reactive-SH groups, and spectro-photometric tyrosine titration were indistinguishable from Hb A. Nevertheless, Hb LF was more unstable than Hb A at 55 C. The propositus had accelerated blood destruction although six other heterozygotes for Hb LF did not. A second defect in red cell enzymes or red cell lipids of the propositus was not demonstrable with the technics used but the possibility that the simultaneous occurrence of Hb LF and an otherwise "silent" red cell defect may lead to a hemolytic state remains an attractive explanation. The data provided by this family study did not permit a definite conclusion about the relationship of clinically evident hemolysis in the propositus to the presence of the abnormal hemoglobin.