HB Duan [α75(EF4)ASP→ALA), HB Westmead [α122(H5)HIS→GLN], and α-Thalassemia-2 (-4.2 KB Deletion) in a Chinese Family

Abstract

Detailed data are presented concerning the relative amounts of Hb A and two α chain variants (Hb Duan with α75 Asp→Ala, and Hb Westmead with α 122 His→Gln), and the occurrence of an α-thalas-semia-2 heterozygosity in five members of a small Chinese family. The three children who have the three abnormalities inherited the α-Duan and a-thalassemia-2 heterozygosities from their father, and the α-Westmead heterozygosity from their mother. The base substitution which leads to the synthesis of the a-Duan chain occurred at codon 75 of the α1 globin gene of the chromosome which also carried the α-thalassemia-2 deletion; the concentration of α-Duan (37% of total α) is similar to that observed for other α chain variants, linked to an α-thalassemia-2 condition.