HBG1: Hemoglobin Subunit Gamma 1
A key component of fetal hemoglobin (HbF), encoded by the HBG1 gene, involved in oxygen transport and implicated in hemoglobinopathies.
Gene Information Card
| Symbol | HBG1 |
|---|---|
| Full Name | Hemoglobin Subunit Gamma 1 |
| Gene Type | Protein coding |
| Chromosomal Location | 11p15.4 |
| NCBI Gene ID | 3047 ncbi.nlm.nih.gov/gene/3047 |
| Ensembl ID | ENSG00000213934 |
| UniProt ID | P69891 |
| OMIM ID | 142200 |
| HGNC ID | 4832 |
| Aliases | HBG-T1, HBG-T2, gamma-globin, HbF Ggamma |
Description
The HBG1 gene encodes the gamma-1 globin chain, a component of fetal hemoglobin (HbF, α2γ2). During fetal development, HBG1 and its paralog HBG2 produce gamma globin chains that combine with alpha globin to form HbF. After birth, expression of HBG1 is normally silenced and replaced by adult beta globin (HBB). Mutations or deletions in the HBG1 gene or its regulatory regions can lead to hereditary persistence of fetal hemoglobin (HPFH), which can ameliorate the severity of sickle cell disease and beta thalassemia. The gene is located in the beta-globin cluster on chromosome 11.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Hereditary Persistence of Fetal Hemoglobin (HPFH) | Deletions or point mutations in the HBG1 promoter or regulatory regions cause continued expression of gamma globin into adulthood, increasing HbF levels. | ClinVar, OMIM |
| Sickle Cell Disease (modifier) | Elevated HBG1 expression (HbF) inhibits polymerization of sickle hemoglobin (HbS), reducing disease severity. | ClinVar, NCBI |
| Beta Thalassemia (modifier) | Increased gamma globin from HBG1 compensates for deficient beta globin, alleviating anemia. | ClinVar, OMIM |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Bone Marrow | 0.0 | Not detected |
| Fetal Liver | High | High expression during fetal development |
| Spleen | 0.0 | Not detected |
| Whole Blood (adult) | 0.0 | Not detected |
| Erythroid cells (fetal) | High | High expression |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| K562 (erythroleukemia) | High | Constitutive expression of gamma globin |
| HEL (erythroleukemia) | Moderate | Variable expression |
| HUDEP-2 (erythroid progenitor) | High | Fetal-like expression pattern |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| -175 T>C (HBG1 promoter) | SNP | Rare | Upregulation of HBG1; associated with HPFH |
| -158 C>T (HBG2 promoter) | SNP | Common in some populations | Modest increase in HbF levels |
| HbF-Sardinia (A->T at codon 75) | Missense | Rare | Structural variant; no major clinical effect |
| Deletion of HBG1-HBG2 intergenic region | Deletion | Rare | Causes HPFH type 1 |
Mutation functional classification
Loss of Function (LOF)
Loss-of-function mutations in HBG1 are rare and typically not associated with disease due to redundancy with HBG2; however, complete deletion may reduce HbF levels.
Gain of Function (GOF)
Promoter mutations (e.g., -175 T>C) that increase HBG1 transcription are gain-of-function, leading to HPFH and beneficial effects in sickle cell disease and beta thalassemia.
Dominant Negative (DN)
No dominant negative mutations have been described for HBG1.
View complete mutation data：
Gene Ontology (GO)
| • oxygen carrier activity (GO:0005344) | • heme binding (GO:0020037) |
| • hemoglobin complex (GO:0005833) | • oxygen transport (GO:0015671) |
| • hydrogen peroxide catabolic process (GO:0042744) |
Pathways
• Oxygen transport (Reactome: R-HSA-1480926)
• Erythrocytes take up oxygen and release carbon dioxide (Reactome: R-HSA-1247673)
• Metabolism of proteins (Reactome: R-HSA-392499)
Protein Summary
The HBG1 protein (gamma-1 globin) is a 147-amino acid polypeptide that forms part of fetal hemoglobin (HbF). It contains a heme-binding pocket and is responsible for oxygen transport in the fetus. The gamma chain differs from adult beta globin at 39 residues, conferring a higher oxygen affinity that facilitates oxygen transfer from maternal to fetal circulation. Postnatally, HBG1 expression is epigenetically silenced, but reactivation is a therapeutic goal for hemoglobinopathies.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| HBG1 Knockout HEK293 Cell Line | EDJ-KQ50342 | Human | 3047 | Details Get a Quote |
| HBG1 Knockout HeLa Cell Line | EDJ-KQ53498 | Human | 3047 | Details Get a Quote |
| HBG1 Knockout A-549 Cell Line | EDJ-KQ61968 | Human | 3047 | Details Get a Quote |
| HBG1 Knockout HCT 116 Cell Line | EDJ-KQ70449 | Human | 3047 | Details Get a Quote |
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