The first Japanese case of Hb Santa Ana, an unstable abnormal hemoglobin, identified rapidly by electrospray ionization mass spectrometry.

Two members of a family had chronic hemolytic anemia due to unstable hemoglobin. The abnormal beta-chain with a molecular weight of 16 u smaller than the normal beta-chain was found within 5 minutes by analysis using electrospray ionization mass spectrometry. The substitution of amino acid was also determined rapidly by this new strategy. The leucine at the 88th position of the normal beta-chain was substituted by proline in the hemoglobin as in Hb Santa Ana. This is the first report of a Japanese case of Hb Santa Ana; the clinical course was similar to that in the previously reported cases.