An Egyptian β-thalassaemia heterozygote with normal haemoglobins A2 and F: A problem in population screening

An Egyptian mother with anisocytosis, low MCV, low MCH but normal haemoglobins A2 and F was probably heterozygous for both the β- and δ-thalassaemia traits on alternate chromosomes—in trans position. Her son was a true β-thalassaemia heterozygote. Her daughter was probably a recombinant—a δ-β thalassaemia heterozygote. The importance of family studies is stressed when haemoglobins A2 and F are normal while red blood cells are abnormal.