BLM Gene (Bloom Syndrome RecQ Like Helicase)
A key helicase in genome stability, associated with Bloom syndrome and cancer predisposition.
Gene Information Card
| Symbol | BLM |
|---|---|
| Full Name | BLM RecQ like helicase |
| Gene Type | Protein coding |
| Chromosomal Location | 15q26.1 |
| NCBI Gene ID | 641 ncbi.nlm.nih.gov/gene/641 |
| Ensembl ID | ENSG00000197299 |
| UniProt ID | P54132 |
| OMIM ID | 604610 |
| HGNC ID | 1058 |
| Aliases | BS, RECQL3, RECQ2, MUTS, BLM helicase |
Description
The BLM gene encodes a member of the RecQ helicase family, essential for maintaining genomic stability. The protein unwinds DNA duplexes and resolves aberrant structures such as Holliday junctions and G-quadruplexes, playing critical roles in DNA replication, repair, and recombination. Loss-of-function mutations cause Bloom syndrome, a disorder characterized by growth deficiency, immunodeficiency, sun-sensitive skin lesions, and a high predisposition to various cancers.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Bloom Syndrome | Biallelic loss-of-function mutations in BLM lead to genomic instability, sister chromatid exchanges, and cancer predisposition. | OMIM #210900 |
| Breast Cancer | BLM mutations and reduced expression are associated with increased risk and poor prognosis. | ClinVar, COSMIC |
| Colorectal Cancer | Somatic BLM alterations contribute to microsatellite instability and tumor progression. | COSMIC, NCBI |
| Lung Cancer | BLM overexpression in some subtypes may promote resistance to DNA-damaging therapies. | COSMIC |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 12.3 | Medium |
| Bone Marrow | 8.7 | Medium |
| Lymph Node | 6.5 | Low |
| Brain | 2.1 | Low |
| Liver | 1.8 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HeLa | 9.4 | Cervical cancer cell line |
| A549 | 7.2 | Lung carcinoma cell line |
| MCF7 | 6.8 | Breast cancer cell line |
| K562 | 11.1 | Leukemia cell line |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.2207_2212delATCTGAinsTAGATTC (p.Tyr736Leufs*5) | Frameshift | <0.1% | Loss of function; Bloom syndrome |
| c.1642C>T (p.Gln548*) | Nonsense | <0.1% | Loss of function; Bloom syndrome |
| c.2407C>T (p.Arg803Trp) | Missense | <0.1% | Impaired helicase activity |
| c.3592delA (p.Ser1198Valfs*2) | Frameshift | <0.1% | Loss of function; Bloom syndrome |
Mutation functional classification
Loss of Function (LOF)
Most BLM mutations are loss-of-function, leading to truncated or unstable protein, defective helicase activity, and genomic instability characteristic of Bloom syndrome.
Gain of Function (GOF)
No well-documented gain-of-function mutations; overexpression in some cancers may confer proliferative advantage but is not classified as gain-of-function.
Dominant Negative (DN)
Rare missense mutations may exert dominant-negative effects by interfering with wild-type BLM function, though evidence is limited.
View complete mutation data：
Gene Ontology (GO)
| • DNA helicase activity | • ATP binding |
| • DNA replication | • DNA repair |
| • telomere maintenance | • chromosome segregation |
Pathways
• Homologous recombination
• Fanconi anemia pathway
• DNA damage response
• Telomere maintenance
Protein Summary
BLM is a 1417-amino acid protein with a conserved helicase domain and a C-terminal RecQ C-terminal (RQC) domain. It forms a complex with topoisomerase IIIα, RMI1, and RMI2 (the BTR complex) to process DNA intermediates during replication and repair. BLM resolves Holliday junctions, suppresses sister chromatid exchanges, and maintains telomere integrity. Its deficiency leads to hyper-recombination and chromosomal instability.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| BLMH Knockout HEK293 Cell Line | EDJ-KQ2562 | Human | 642 | Details Get a Quote |
| BLMH Knockout HCT 116 Cell Line | EDJ-KQ21860 | Human | 642 | Details Get a Quote |
| BLMH Knockout A-549 Cell Line | EDJ-KQ23226 | Human | 642 | Details Get a Quote |
| BLMH Knockout HeLa Cell Line | EDJ-KQ23227 | Human | 642 | Details Get a Quote |
| BLM (p.T1034=) Point Mutation in HAP1 Cell Line | EDC03410 | Human | 641 | Details Get a Quote |
| BLM (p.A1177=) Point Mutation in HAP1 Cell Line | EDC03411 | Human | 641 | Details Get a Quote |
| BLM (p.L1315=) Point Mutation in HAP1 Cell Line | EDC03412 | Human | 641 | Details Get a Quote |
| BLM (c.2308-50G>A )Point Mutation in HAP1 Cell Line | EDC03409 | Human | 641 | Details Get a Quote |
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