Making sense of DNA mistakes in childhood cancer
Written by Dianne Sylvester, University of Sydney PhD candidate at the Children's Cancer Research Unit, and Professor Jennifer Byrne, Head of the Children's Cancer Research Unit.
It has long been suspected that cancer can be written in our genes, or in our DNA. This could also be true more often for childhood cancer patients. Cancer diagnosed at a young age could indicate a genetic cause, through a mistake written in the DNA. It is thought that approximately 8-10% of childhood cancer patients carry a mistake in their DNA that may have caused their cancer. This is important, as childhood cancer patients with underlying DNA mistakes may be at greater risk of developing second cancers.
In our study recently published in the Journal of Medical Genetics, we compared the results from 6 different studies that investigated underlying genetic mistakes in childhood cancer patients. We found that these 6 studies differed in the types of childhood cancers that they examined, and also in the regions of DNA that they selected to search for mistakes.
Furthermore, of the DNA mistakes that these 6 studies reported, only about half of them ‘made sense’, meaning that the type of cancer diagnosed in the child was known to be associated with the DNA mistake that was detected. Most of the other DNA mistakes were known to be associated with cancer development in adults. We are yet to understand if and how mistakes in genes associated with adult cancers contribute to the development of childhood cancers.
Our study highlights the value of comparing DNA sequencing results from large numbers of childhood cancer patients. By analysing the DNA from many childhood cancer patients, we will understand which mistakes are likely to be important, and which mistakes may not matter.
In the future, more childhood cancer patients will have their DNA investigated for mistakes that may have caused their cancer. We need to continue research of these underlying mistakes, so that more of them ‘make sense’ in children.
If we know which children have underlying genetic mistakes that confer a risk of developing cancer, this could lead to early detection, more successful treatment, as well the ultimate goal of cancer prevention.
Thank you to the Kids' Cancer Project for supporting our childhood cancer research and for profiling this research in their recent article.