Globin chain synthesis in haemoglobin New York (β113 valine α[ glutamic acid)

Abstract

The presence of Hb New York was confirmed in a Chinese family in which affected members have occasional red cells with Hb H-like inclusions and a relative decrease in α chain synthesis, suggestive of a coexisting α thalasssaemia trait. However, globin gene mapping and DNA hybridization revealed no deletion of the α genome. Timed-incubation experiments showed that the rate of synthesis of β(NY) chain was greater than that of normal β chain in the early periods. Chromatographic separation of Hb NY and Hb A before chain analysis revealed preferential binding of newly synthesized α chains to β(NY), with a four-fold increase in specific activity of the α(Hb NY) chains. It is concluded that β(NY) chain is being synthesized more rapidly and its increased turnover may account for this presentation of apparent α chain deficiency.