GALK1 Gene - Galactokinase 1
Essential enzyme in galactose metabolism; mutations cause galactosemia type 2
Gene Information Card
| Symbol | GALK1 |
|---|---|
| Full Name | galactokinase 1 |
| Gene Type | protein-coding |
| Chromosomal Location | 17q25.1 |
| NCBI Gene ID | 2584 ncbi.nlm.nih.gov/gene/2584 |
| Ensembl ID | ENSG00000108479 |
| UniProt ID | P51570 |
| OMIM ID | 604313 |
| HGNC ID | 4118 |
| Aliases | GK1, GALACTOKINASE |
Description
The GALK1 gene encodes galactokinase 1, an enzyme that catalyzes the first step of galactose metabolism: the ATP-dependent phosphorylation of galactose to galactose-1-phosphate. This enzyme is critical for the Leloir pathway of galactose utilization. Mutations in GALK1 cause galactosemia type 2 (OMIM #230200), an autosomal recessive disorder characterized by cataracts, galactosuria, and elevated blood galactose levels.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Galactosemia type 2 | Loss-of-function mutations in GALK1 impair galactose phosphorylation, leading to accumulation of galactose and galactitol, causing cataract formation. | OMIM #230200; ClinVar |
| Cataract (early-onset) | Galactitol accumulation in the lens due to GALK1 deficiency causes osmotic stress and lens opacification. | OMIM #604313; NCBI GeneReviews |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Liver | 12.5 | Medium |
| Kidney | 8.3 | Medium |
| Small intestine | 6.7 | Low |
| Pancreas | 5.1 | Low |
| Heart | 4.2 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HepG2 | 15.2 | Hepatocellular carcinoma cell line |
| HEK293 | 9.8 | Embryonic kidney cells |
| HeLa | 7.1 | Cervical adenocarcinoma cells |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.82C>T (p.Arg28Cys) | Missense | Rare | Reduced enzyme activity; associated with galactosemia type 2 |
| c.580G>A (p.Gly194Arg) | Missense | Rare | Loss of function; pathogenic in ClinVar |
| c.1144C>T (p.Arg382*) | Nonsense | Rare | Premature truncation; complete loss of function |
Mutation functional classification
Loss of Function (LOF)
Most pathogenic GALK1 mutations are loss-of-function, leading to galactokinase deficiency and galactosemia type 2.
Gain of Function (GOF)
No gain-of-function mutations reported for GALK1.
Dominant Negative (DN)
No dominant-negative mutations reported; disease is autosomal recessive.
View complete mutation data：
Gene Ontology (GO)
| • galactokinase activity (GO:0004335) | • ATP binding (GO:0005524) |
| • galactose metabolic process (GO:0006012) | • carbohydrate phosphorylation (GO:0046835) |
Pathways
• Galactose metabolism (KEGG: hsa00052)
• Leloir pathway (Reactome: R-HSA-70370)
Protein Summary
Galactokinase 1 is a 392-amino acid enzyme that belongs to the GHMP kinase family. It catalyzes the ATP-dependent phosphorylation of galactose to galactose-1-phosphate. The protein is primarily expressed in liver, kidney, and small intestine. Deficiency leads to galactosemia type 2, characterized by cataracts and galactosuria.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| GALK1 Knockout HEK293 Cell Line | EDJ-KQ3079 | Human | 2584 | Details Get a Quote |
| GALK1 Knockout HeLa Cell Line | EDJ-KQ22996 | Human | 2584 | Details Get a Quote |
| GALK1 Knockout A-549 Cell Line | EDJ-KQ24371 | Human | 2584 | Details Get a Quote |
| GALK1 Knockout HCT 116 Cell Line | EDJ-KQ24372 | Human | 2584 | Details Get a Quote |
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