Two women with polycythemia vera and heterozygosity (GdB/GdA) at the X-chromosome-linked locus for glucose-6-phosphate dehydrogenase were studied to determine the nature of the cellular origin of their polycythemia.
In spite of lymphocytosis and the clinical signs and symptoms of leukemia, the patient exhibited at the same time presumptive elements of polycythemia (high LAP index levels, a high number of neutrophils).
A new abnormal hemoglobin, Hb Villejuif [beta 123(H1) Thr----Ile] has been discovered during the exploration of a polycythemia in a 87-year-old patient of French origin.
Functional studies examining number and binding affinity of the EPO-receptor on erythroid progenitors from three hereditary polycythemia patients demonstrated no abnormalities.
Second, we have isolated a mutant of gp55 (F-gp55-M1) which binds, but fails to activate, EPO-R. We have compared the transforming activity of this gp55 mutant with the EPO-R-gp55 fusion proteins and with other variants of gp55, including wild-type polycythemia Friend gp55 and Rauscher gp55.