- Hb Chad or alpha 223(B4)Glu----Lys beta 2 observed in members of a Surinam family in association with alpha-thalassemia-2 and with Hb S. Codrington, J.F., Codrington, F.A., Wisse, J.H., Wilson, J.B., Webber, B.B., Wong, S.C., Huisman, T.H. Hemoglobin (1989)