Haemoglobin D Los Angeles, D-beta +-thalassaemia, and D-beta o-thalassaemia. A report of two Canadian families.

The first 2 Canadian cases of combinations of Hb D Los Angeles and beta-thalassaemia were found in an Italian family and an East Indian family in Hamilton, Ont. The structure of the Hb D variant was identified by radioimmunoassay. The beta +-thalassaemia trait in the Italian family and the beta o-thalassaemia trait in the East Indian family were confirmed by studies of globin chain synthesis. Previous cases of Hb D-beta-thalassaemia were summarized and family studies of the 2 new cases were presented.