Erythrocyte Enzymatic Abnormalities in HEMPAS (Hereditary Erythroblastic Multinuclearity with a Positive Acidified‐Serum Test)

Summary. In one type of hereditary dyserythropoietic anaemia, HEMPAS (hereditary erythroblastic multinuclearity with a positive acidified‐serum test) striking increases in the activity of some, but not all, erythrocyte enzymes have been detected in three cases. Since there was only minimal reticulocytosis, these enzyme changes cannot be accounted for by the presence of a young erythrocyte population. It is suggested that the enzymatic abnormalities of HEMPAS result from abnormal karyo‐ and cyto‐kinesis of the erythroid precursors.