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Homologous Recombination Deficiency

Deoxyribonucleic acid (DNA) is a molecule found in our cells. DNA acts as an instruction manual that directs our body’s processes. Given its essential role, it is important that our DNA is maintained in a healthy, error-free state. DNA has the unique ability to repair itself to remain as error-free as possible. This process is known as homologous recombination.

However, some cells might lose this unique ability to self-repair their DNA through homologous recombination. This happens as a result of errors, called mutations, being acquired in certain key regions of the DNA known as genes. When such genes become faulty, cells are no longer able to repair their own DNA. This state is called homologous recombination deficiency (HRD). Two such genes which are commonly responsible for HRD are BRCA1 and BRCA2, though mutations in other genes are also known to give rise to HRD.

As such, such cells slowly fail to carry out their processes normally and might turn cancerous. For example, the cancerous tumours seen in ovarian and prostate cancers are regularly seen to have HRD (known as HRD-positive tumours).

How do I know if my tumour is HRD-positive?

However, not all tumours are HRD-positive. Whether a tumour is HRD-positive or not can be determined by a type of test known as somatic testing, which is carried out in a laboratory. If a tumour is found to be HRD-positive, it would mean that certain therapies might be more effective in treating the tumour. A good example of such a therapy is a type of medication called PARP inhibitors.

For more information on Somatic Genetic Testing, please download the brochures here:

English brochure

Chinese brochure