Congenital sideroblastic anaemia in a girl.

A girl with severe, sideroblastic, ‘dimorphic’ anaemia, probably present since birth, is reported. She has extremely low erythrocyte protoporphyrin levels and low erythrocyte coproporphyrin levels. Porphyrin synthesis from ALA proceeds normally in haemolysates from her red cells in vitro. No ALA could be demonstrated in plasma or red cells using an amino acid analyser (normal finding). Glutamic acid and glycine levels in erythrocytes were elevated. In contrast to the more common sex‐linked form of congenital sideroblastic anaemia, which is thought to be caused by a partial block in conversion of coproporphyrin to protoporphyrin, the metabolic defect in our patient seems to be in some step in haeme synthesis prior to ALA, perhaps an ALA‐synthetase deficiency. Four similar cases in females have been traced in the literature. The mode of inheritance of this disease is unknown.