Human T gamma globin chain is a variant of A gamma chain (A gamma Sardinia).

Abstract
Isoelectric focusing, cellulose acetate electrophoresis and carboxymethylcellulose chromatography in the presence of Nonidet P-40 allow the separation of pure .gamma. globin chains into 2 fractions. Amino acid analysis of their cyanogen bromide fragment 3 (.gamma.CB3) identifies these fractions as the separated G.gamma.(Gly-136) and A.gamma.(Ala-136) globin chains. Fingerprint and amino acid analyses of the .gamma.Tp9 tryptic peptide from the purified A.gamma. and G.gamma. fractions from 2 different patients demonstrate that the commonly occurring .gamma.Sardinia variant (.gamma. 75 Ile .fwdarw. Thr), also known as T.gamma. chain, has Ala in position 136. The T.gamma. gene is apparently an allele of the A.gamma. locus (A.gamma.Sardinia) rather than a 3rd .gamma. locus.