PYRIMIDINE-5'-NUCLEOTIDASE DEFICIENCY AS A CONGENITAL CAUSE OF NONSPHEROCYTIC HEMOLYTIC-ANEMIA

An 11-year-old girl had marked haemolytic anaemia since the first year of life. Physical examination revealed scleral and cutaneous icterus and slight splenomegaly. Haemoglobin concentration was reduced to 9.5 g/dl, while platelet count and bilirubin concentration were increased (350 000/mul and 2.2 mg/dl, respectively). The erythrocytes showed mar ked basophilic stipling, its extent typical of pyrimidine-5'-nucleotid ase deficiency. The enzyme activity in the erythrocytes was 15% of nor mal. Deficiency of this enzyme, inherited as an autosomal recessive, i s probably one of the most common erythrocyte enzyme deficiencies caus ing haemolytic anaemia. It brings about the intracellular accumulation of pyrimidine nucleotides which via secondary metabolic changes cause s an accelerated destruction of erythrocytes. There is no known causat ive treatment: splenectomy is ineffective against the anaemia.