HBG2 Gene - Hemoglobin Subunit Gamma 2
A key gene in fetal hemoglobin production, associated with hereditary persistence of fetal hemoglobin and beta-thalassemia
Gene Information Card
| Symbol | HBG2 |
|---|---|
| Full Name | Hemoglobin Subunit Gamma 2 |
| Gene Type | protein-coding |
| Chromosomal Location | 11p15.4 |
| NCBI Gene ID | 3048 ncbi.nlm.nih.gov/gene/3048 |
| Ensembl ID | ENSG00000196565 |
| UniProt ID | P69892 |
| OMIM ID | 142250 |
| HGNC ID | 4832 |
| Aliases | HBG-T1, HBG-T2, gamma-globin, HbF Ggamma |
Description
The HBG2 gene encodes the gamma-2 globin chain, a component of fetal hemoglobin (HbF, α2γ2). During fetal development, HBG2 is expressed in the yolk sac and fetal liver, and its expression declines after birth as adult hemoglobin (HbA, α2β2) becomes predominant. Mutations in HBG2 are associated with hereditary persistence of fetal hemoglobin (HPFH) and can modulate the severity of beta-thalassemia and sickle cell disease.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Hereditary Persistence of Fetal Hemoglobin (HPFH) | Increased HBG2 expression due to promoter mutations or deletions leads to elevated HbF levels in adulthood, compensating for defective beta-globin | ClinVar, OMIM |
| Beta-Thalassemia | Upregulation of HBG2 can ameliorate anemia by increasing HbF production, reducing the need for transfusions | NCBI, OMIM |
| Sickle Cell Disease | Elevated HbF from HBG2 expression inhibits sickle hemoglobin polymerization, reducing disease severity | ClinVar |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Blood | 0.0 | Not detected |
| Bone Marrow | 0.0 | Not detected |
| Fetal Liver | High | High expression during development |
| Spleen | 0.0 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| K562 | High | Erythroleukemia cell line; expresses gamma-globin |
| HEL | Moderate | Erythroleukemia cell line |
| HUDEP-2 | High | Erythroid progenitor cell line |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| -175 T>C (HBG2 promoter) | SNV | Rare | Upregulates HBG2 expression; associated with HPFH |
| -158 C>T (HBG2 promoter) | SNV | Common in some populations | Modestly increases HbF levels |
| c.1A>G (p.Met1Val) | Missense | Rare | May affect protein initiation; clinical significance uncertain |
Mutation functional classification
Loss of Function (LOF)
Loss-of-function mutations in HBG2 are rare and may reduce gamma-globin production, but compensatory mechanisms often maintain HbF levels.
Gain of Function (GOF)
Promoter mutations (e.g., -175 T>C) increase HBG2 transcription, leading to elevated HbF (gain of function).
Dominant Negative (DN)
No dominant-negative mutations reported for HBG2.
View complete mutation data：
Gene Ontology (GO)
| • oxygen carrier activity | • heme binding |
| • iron ion binding | • oxygen transport |
| • blood coagulation |
Pathways
• Erythropoietin signaling pathway
• Hemoglobin synthesis
• Oxygen transport
Protein Summary
Hemoglobin subunit gamma 2 (Hb Ggamma) is a 147-amino acid protein that forms part of fetal hemoglobin (HbF). It binds heme and oxygen, facilitating oxygen transport in the fetus. The gamma-2 chain differs from the gamma-1 chain (HBG1) by a single amino acid (glycine vs. alanine at position 136). Postnatally, HBG2 expression is silenced, but reactivation is a therapeutic target for hemoglobinopathies.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| HBG2 Knockout HEK293 Cell Line | EDJ-KQ50343 | Human | 3048 | Details Get a Quote |
| HBG2 Knockout HeLa Cell Line | EDJ-KQ53499 | Human | 3048 | Details Get a Quote |
| HBG2 Knockout A-549 Cell Line | EDJ-KQ61969 | Human | 3048 | Details Get a Quote |
| HBG2 Knockout HCT 116 Cell Line | EDJ-KQ70450 | Human | 3048 | Details Get a Quote |
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