Two new unstable haemoglobins leading to chronic haemolytic anaemia: Hb Caruaru [beta122 (GH5) Phe-->Ser], a probable case of germ line mutation, and Hb Olinda [beta22 (B4) - 25 (B7)], a deletion of a 12 base-pair sequence.

We describe here two new unstable beta-globin variants, Hb Caruaru and Hb Olinda, found in northeastern Brazil, both associated with chronic haemolytic anaemia. Haemoglobin Caruaru is caused by a single base substitution at codon 122 (TTC-->TCC), possibly originating from the germ line cells of the patient's grandmother. Haemoglobin Olinda is also a de novo mutation, caused by a 12 bp deletion leading to the removal of the 22nd to the 25th residues of the normal beta-globin chain.