People have asked why is it that mutations in other genetic diseases like cystic fibrosis muscular dystrophy don’t directly cause cancer. Well, the answer is that to date, the majority of mutations that lead up to cancer involve mutations in parts of the DNA called regulatory genes. These are sections of the DNA that either act as the breaks and checks for a dividing cell (called tumour surpressor genes) or as controls and regulates how the cell grows (called proto-oncogenes).
As explained before the likelyhood of the same mutation in every cell is low, but it does happen. For cancer cells to arise, the mutations need to affect both the tumour surpressor genes and the proto-oncogenes (turning them into cancer promoting oncogenes). These mutations have to occur in a series of steps which is why the older you get, the more likely you’ll develop benign tumours and eventually cancer if left unchecked.
If this is the case, then why is it young children get cancer as well? That is because it’s possible for mutations in the genes to affect a child at birth. If the mutations affect either the tumour surpressor genes or the proto-oncogenes at birth, the series of mutations required for a cell to become cancerous is much less than before. The more damaged the regulatory genes are, the faster the progression to a cancer cell.
This is how the cancer can affect younger people across generations. If you inherit an already damaged gene from your parents, you need less unchecked mutations to occur in your body before it becomes a cancer cell. That’s why it’s always advisable to frequently go for checkups if you have a family history of cancer. It’s better to be safe rather than dead.
This year Footsteps in the Mirror will be blogging to raise money for the Association for International Cancer Research which is a non-profit organisation that helps fund cancer research throughout the world. If you’re willing to help, you can sign up on the Blogathon website and pledge your amount right here. Help make a difference, no matter how small it may be.