Hb A₂-Manzanares Or α₂δ₂121(Gh4) Glu→Val, An Unstable δ Chain Variant Observed in a Spanish Family

Abstract

A slowly moving variant of Hb A2 was present in a 25-year-old Spanish woman and her mother, and was found to have a Glu replaced by Val substitution at position 121 of the delta chain. The variant was unstable and precipitated gradually during anion exchange chromatography. The effect of this substitution on the stability of the protein is apparently more severe for Hb A2 than for Hb A because Hb Beograd (beta 121 Glu replaced by Val) has normal physicochemical properties.