Hb Nishinomiya [Leu-Gly-inserted between codons 69(E13) and 70(E14) of beta]: a novel unstable hemoglobin with reduced oxygen affinity found in a patient with spherocytic hemolysis.

Substantially decreased oxygen saturation levels were incidentally detected by pulseoxymetry in a patient with spherocytic hemolysis who was undergoing laparoscopic splenectomy. Molecular analysis revealed that he was carrying hemoglobin (Hb) Nishinomiya, a novel Hb variant [Leu-Gly-inserted between codons 69(E13) and 70(E14) of beta]. Amino acid substitutions around positions 70-73(E13-17) of the beta chain are likely to change stability and oxygen affinity, as has been demonstrated in several Hb variants including Hb Seattle. The apparent substitution of the amino acid residues in the heme pocket of the beta chain explains the decreased stability and oxygen affinity of Hb Nishinomiya.