HBG2

The gamma globin genes (HBG1 and HBG2) 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. In some beta-thalassemias and related conditions, gamma chain production continues into adulthood. 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). The former is predominant at birth. The order of the genes in the beta-globin cluster is: 5'- epsilon -- gamma-G -- gamma-A -- delta -- beta--3'.

Full Name

Hemoglobin Subunit Gamma 2

Function

Gamma chains make up the fetal hemoglobin F, in combination with alpha chains.

Biological Process

Cellular oxidant detoxification Source: GOC
Hydrogen peroxide catabolic process Source: GO_Central

Cellular Location

Cytosol; Hemoglobin complex; Blood microparticle; Haptoglobin-hemoglobin complex

Involvement in disease

Cyanosis transient neonatal (TNCY):
A disorder characterized by cyanosis in the fetus and neonate, due to a defect in the fetal hemoglobin chain which has reduced affinity for oxygen. Some patients develop anemia resulting from increased destruction of red cells containing abnormal or unstable hemoglobin. The cyanosis resolves spontaneously by 5 to 6 months of age or earlier, as the adult beta-globin chain is produced and replaces the fetal gamma-globin chain.

PTM

Acetylation of Gly-2 converts Hb F to the minor Hb F1.