[Diphosphoglyceromutase deficiency: new cases associated with erythrocytosis]

New cases of diphosphoglyceromutase (DPGM) have been detected, associated with erythrocytosis in two unrelated families. The deficiency appears to be inherited as an autosomal dominant trait. Diphosphoglycerate phosphatase activity paralleled DPGM activity in all the subjects. Three of the latter displayed complete DPGM deficiency with about 0.4% of the normal 2,3-diphosphoglycerate (2,3 DPG) level. The other four showed partial deficiency (about 50% normal mean) with a similar decrease in 2,3-DPG level. The P50 values are in agreement with the red cell 2,3-DPG concentrations. Il all the deficient subjects the ATP level was elevated and the pattern of glycolytic intermediates was disturbed, with an increase in fructose 1,6-diphosphate, triose-phosphates, 3-phosphoglycerate, glucose 1,6-diphosphate, and reduced or normal levels of glucose-6-phosphate and fructose-6-phosphate.