Hb Duan [alpha 75(EF4)Asp----Ala], Hb Westmead [alpha 122(H5)His----Gln], and alpha-thalassemia-2 (-4.2 Kb deletion) in a Chinese family.

Detailed data are presented concerning the relative amounts of Hb A and two alpha chain variants (Hb Duan with alpha 75 Asp----Ala, and Hb Westmead with alpha 122 His----Gln), and the occurrence of an alpha-thalassemia-2 heterozygosity in five members of a small Chinese family. The three children who have the three abnormalities inherited the alpha-Duan and alpha-thalassemia-2 heterozygosities from their father, and the alpha-Westmead heterozygosity from their mother. The base substitution which leads to the synthesis of the alpha-Duan chain occurred at codon 75 of the alpha 1 globin gene of the chromosome which also carried the alpha-thalassemia-2 deletion; the concentration of alpha-Duan (37% of total alpha) is similar to that observed for other alpha chain variants, linked to an alpha-thalassemia-2 condition.