Claim: HBG2 is the type of gamma chain produced by the gamma globin gene which is predominant at birth.
Evidence: The gamma globin genes (HBG1 and HBG2, this gene) are normally expressed in the fetal liver, spleen and bone marrow. Two gamma chains together with two alpha chains constitute fetal hemoglobin (HbF) which is normally replaced by adult hemoglobin (HbA) at birth.