Hemoglobin Miyashiro (β 23[B5] Val → Gly) an Electrophoretically Silent Variant Discovered by the Isophopanol Test

A new unstable hemoglobin was discovered in a Japanese boy without any signs of hemolytic disease during screening of patients by the isopropanol test. The abnormal hemoglobin was found in three generations. This slightly unstable hemoglobin could not be separated from Hb A by electrophoresis. All carriers showed an increased whole blood oxygen affinity. Structural studies demonstrated a previously unreported amino acid substitution, beta 23[B5] valine substituting for glycine. This new unstable variant has been named Hb Miyashiro.