A new unstable haemoglobin variant: Hb Shanghai [beta 131(H9)Gln----Pro] found in China.

A 34-year-old woman patient was found to have a chronic hereditary haemolytic anaemia. No abnormal haemoglobin band was detected by conventional electrophoresis, but a slow beta chain could be separated on urea-carboxymethyl cellulose chromatography. Investigations of the patient's haemoglobin revealed an unstable component. Analyses of chemical structure, including isolation and TPCK trypsin digestion of the abnormal globin chain. HPL chromatography, amino acid composition as well as sequence determination of the abnormal peptide, indicated that a glutamine was replaced by a proline at position beta 131 (H9). Biosynthesis studies demonstrated a normal rate of synthesis but relatively fast degradation of the mutant beta chain. The new variant is named as Hb Shanghai according to the place where it was discovered.