Claim: HBG2 is one of the two types of gamma chains produced by gamma globin gene(are normally expressed in the fetal liver, spleen and bone marrow) with glycine for residue 136.
Evidence: The gamma globin genes (HBG1 and HBG2, this gene) are normally expressed in the fetal liver, spleen and bone marrow. The two types of gamma chains differ at residue 136 where glycine is found in the G-gamma product (HBG2) and alanine is found in the A-gamma product (HBG1).