Hereditary ring sideroblastic anaemia and Christmas disease in a Swedish family.

The association of hereditary ring sideroblastic anaemia with Christmas disease in a Swedish family is described. We have studied the transmission of the sideroblastic trait, in relation to HLA groups and Christmas disease, and also evaluated the erythrocyte morphology, uroporphyrinogen-I-synthetase activity and S-ferritin for the detection of latent cases of ring sideroblastic anaemia. The proband had ring sideroblastic anaemia, Christmas disease and haemochromatosis. 3 cases of ring sideroblastic anaemia were found among the 12 family members studied. Using the factor IX deficiency as a marker of the X chromosome, it appeared that autosomal transmission of the sideroblastic trait was most likely. The sideroblastic trait did not seem to be linked to HLA-A3-alloantigen. Erythrocyte morphology was normal in all non-anaemic subjects. S-ferritin was found to be increased in all 3 cases of sideroblastic anaemia as well as in 1 non-anaemic relative. Erythrocyte uroporphyrinogen-I-synthetase was elevated in 10 of the 12 family members; those with sideroblastic anaemia had the highest values indicating that uroporphyrinogen-I-synthetase is of importance in the disturbed haem-synthesis of ring sideroblastic anaemia. This interpretation is supported by the positive correlation between S-ferritin values and the uroporphyrinogen-I-synthetase activity.