Аннотация:An abnormal haemoglobin, which on paper electrophoresis has the mobility of Hb J, has been found in two brothers and, in the heterozygous state at least, is not associated with serious clinical abnormality. The structure of this hitherto unreported haemoglobin is α 120 (H3) Ala → Glu and it is named Haemoglobin J Birmingham.