[Familial pyridoxine-responsive sideroblastic anaemia. One case (author's transl)].

In a 24-year old man presenting with hypochromic microcytic anaemia, low reticulocyte count, increased serum iron and bone marrow erythroid hyperplasia with numerous ringed sideroblasts, the diagnosis of sideroblastic anaemia was confirmed by radioisotope study and bone marrow electron microscopy. The hereditary nature of the disease was demonstrated by the presence of microcytosis and increased serum iron in the mother and two sisters of the patient. One of the two sisters also had anaemia and abnormal ringed sideroblasts in her bone marrow. Her haemoglobin values and those of the propositus returned to normal under pyridoxine treatment, but hypochromia and abnormal sideroblasts persisted. This case of familial pyridoxine-responsive sideroblastic anaemia is consisted with X-chromosome-mediated transmission. The incomplete effect of pyridoxine suggests a congenital deficiency of some pyridoxine metabolism enzyme or another, as yet unidentified mechanism.