A new unstable hemoglobin, Hb Yokohama beta 31 (B13)Leu substituting for Pro, causing hemolytic anemia

A new unstable hemoglobin was found in a 33-year-old Japanese woman with a history of chronic, partially compensated hemolytic anemia. An electrophoretically silent unstable beta chain was prepared by PCMB precipitation and the amino acid substitution determined as beta 31(B13)Leu substituting for Pro. Her son was a carrier of the same variant, who manifested milder symptoms.