Hereditary nonspherocytic hemolytic disease associated with an altered phospholipid composition of the erythrocytes.

A hemolytic disorder with mild hyperbilirubinemia and reticulocytosis of 6 to 15% was documented in eight members of a large family from the Dominican Republic and was presumed to be present in eight other members. The disorder appeared to be inherited as an autosomal dominant characteristic. Analysis of phospholipids by quantitative thinlayer chromatography revealed a distinct increase in phosphatidyl choline (lecithin) to 35.5 +/- SD 1.3% of the total (normal: 28.2 +/- 1.4%) in erythrocytes of affected members of the family, but not in the cells of unaffected relatives. The alteration appeared to constitute an absolute increase in lecithin content, rather than a decrease in other phospholipids. Erythrocytes from patients with other varieties of hereditary hemolytic disorders and comparable levels of reticulocytosis had normal phospholipid compositions. Plasma lipids of six affected members of the family were not unusual with respect to total lipid weight, total phospholipid, and cholesterol. Three patients with liver disease and jaundice were found to have marked increases in the lecithin content of the erythrocytes, but they also had extremely high plasma levels of total lipid, phospholipids, and cholesterol. Osmotic fragility of the erythrocytes of affected patients was decreased and the increase in fragility after incubation for 24 hr was less than that observed with normal erythrocytes. Autohemolysis after 48 hr was slightly increased and was corrected to nearly normal by the addition of glucose. The activities of 15 enzymes of the erythrocytes of the propositus were normal or elevated and the adenosine triphosphate content was normal. An abnormal hemoglobin could not be demonstrated. The life span of isologous erythrocytes in the propositus was reduced, but homologous erythrocytes survived normally.A causal relationship between the altered phospholipid composition and the hemolytic disorder has not been established.