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RAD51B
RAD51 paralog B
The RAD51B gene provides instructions for making a protein that is crucial in DNA repair, particularly through homologous recombination, and plays a role in maintaining the integrity of the human genome. The RAD51B gene is a key component of the cellular machinery responsible for repairing damaged DNA, especially double-strand breaks.
RAD51B is located on the long (q) arm of chromosome 14, at band 14q24.1. Arm ratio per GRCh38 - banding schematic.
Explore chromosome 14 in the library →Overview
The RAD51B gene, also known as RAD51 paralog B, encodes a protein that is an important member of the RAD51 family of DNA repair proteins. This gene plays a fundamental role in homologous recombination, a critical pathway for repairing potentially harmful DNA double-strand breaks and interstrand cross-links. Proper function of the RAD51B protein is essential for maintaining genomic stability within cells.
Dysregulation or pathogenic variants in the RAD51B gene can impair the efficiency of DNA repair processes. This can lead to an accumulation of DNA damage and an increased risk of genomic instability. Such instability is often associated with a higher susceptibility to various cancers.
What the gene does
The RAD51B gene encodes a protein that belongs to the conserved RecA/RAD51 protein family, which is central to DNA repair by homologous recombination. Specifically, the RAD51B protein functions as a paralog of RAD51, meaning it is a protein with a similar structure and function, arising from a gene duplication event.
In the homologous recombination pathway, RAD51B works in concert with other RAD51 paralogs, such as RAD51C, RAD51D, and XRCC2, to form a complex. This complex is vital for facilitating the loading of the main RAD51 recombinase protein onto single-stranded DNA. This precise loading step is necessary for the subsequent search for a homologous DNA sequence and the exchange of genetic material required for accurate repair of double-strand breaks.
Beyond its direct role in DNA repair, the RAD51B protein is also involved in checkpoint activation and cell cycle regulation following DNA damage. By ensuring that DNA damage is properly recognised and repaired before cell division proceeds, RAD51B contributes significantly to preventing the propagation of errors and maintaining overall genomic integrity.
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Chromosome location
The RAD51B gene is located on chromosome 14, specifically at band 14q24.1. This position refers to long arm (q) of chromosome 14, within region 2, band 4, and sub-band 1. Humans have two copies of chromosome 14, inherited one from each parent. The RAD51B gene contains multiple exons, which are the coding segments of the gene that are transcribed into messenger RNA and eventually translated into the RAD51B protein.
Protein structure
The RAD51B protein is composed of 384 amino acids. Like other proteins in the RecA/RAD51 family, it contains conserved domains that are critical for its function in DNA binding and interaction with other proteins. One notable region is involved in the Interaction with RAD51C, located within amino acids 1-75. This specific region facilitates the physical binding between RAD51B and RAD51C, which is essential for forming the functional protein complex required for homologous recombination and DNA repair.
Key variants
Variants within the RAD51B gene can lead to alterations in the protein's structure or function, potentially impairing its ability to participate effectively in DNA repair processes. Some genetic changes might result in a non-functional protein, while others could reduce its efficiency or stability. The clinical significance of a RAD51B variant is determined by its impact on DNA repair and subsequent effects on genomic stability. Variants are categorised based on their predicted effect, ranging from benign (harmless) to pathogenic (disease-causing).
Sample of pathogenic variants
1 pathogenic / likely-pathogenic variants from ClinVar, ranked by review status (expert-panel-reviewed first). This is a sample; recurrent founder variants in a specific population may not appear here - see the full ClinVar listing via the link above.
| Variant (HGVS) | Protein change | Classification | Evidence | Associated condition |
|---|---|---|---|---|
c.772C>T | p.Gln258Ter | Likely pathogenic | ★☆☆☆ | RAD51B-related cancer predisposition |
Evidence stars indicate ClinVar review status. Individual variant interpretation should always be performed by a qualified clinical laboratory - many variants remain classified as Variants of Uncertain Significance (VUS) pending more research.
Associated conditions
Variants in the RAD51B gene are primarily associated with an increased predisposition to certain types of cancer, particularly ovarian and breast cancer. This heightened risk stems from the gene's critical role in DNA repair via homologous recombination. When this process is compromised due to a pathogenic RAD51B variant, cells become less effective at repairing DNA double-strand breaks. This can lead to an accumulation of genetic mutations and genomic instability, which are hallmarks of cancer development.
No disease links recorded for this gene in our reference set.
UK clinical status
Diet & lifestyle considerations
Maintaining a healthy lifestyle is generally recommended for overall well-being and may contribute to reducing general cancer risk, though specific lifestyle interventions for individuals with RAD51B variants are not definitively established. A balanced diet rich in fruits, vegetables, and whole grains, regular physical activity, and avoiding tobacco and excessive alcohol consumption are widely recognised as beneficial. These general health recommendations are part of a preventative approach to health, but research suggestions do not indicate that they directly counteract the effects of a RAD51B variant.
Supplement considerations
Currently, there is no conclusive scientific evidence to suggest that specific dietary supplements can prevent or treat conditions associated with RAD51B gene variants. While some supplements are marketed for general health or DNA support, their efficacy in mitigating genetic risks linked to RAD51B has not been demonstrated. Individuals considering taking any supplements should always discuss this with a healthcare professional to ensure safety and appropriateness.
Frequently asked questions
What is the RAD51B gene?
The RAD51B gene provides instructions for making a protein that is essential for DNA repair, specifically through a process called homologous recombination. This process fixes harmful DNA double-strand breaks, maintaining the stability of our genetic material.
How does RAD51B relate to cancer risk?
Because RAD51B is crucial for accurate DNA repair, pathogenic variants in this gene can impair the cell's ability to fix DNA damage. This can lead to an accumulation of mutations, genomic instability, and an increased risk of developing certain cancers, including ovarian and breast cancer.
What is homologous recombination?
Homologous recombination is a major DNA repair pathway that uses an intact homologous DNA sequence as a template to accurately repair damaged DNA, especially double-strand breaks. The RAD51B protein is a key factor in orchestrating this process.
Is exercising beneficial if I have a RAD51B variant?
Regular physical activity is broadly recommended for promoting general health and reducing overall cancer risk in the general population. While there are no specific exercise guidelines for individuals with RAD51B variants, maintaining an active lifestyle is generally considered beneficial for well-being.
Are there specific supplements for RAD51B-related conditions?
There is no conclusive scientific evidence that specific dietary supplements can prevent, treat, or directly impact conditions associated with RAD51B gene variants. Any decision to take supplements should be made in consultation with a healthcare professional.