Question: can you cause cancer by curing inherited diseases

Vicky Forster answered on 10 Nov 2013:

Hello Hannah,

Great question! The best short answer is; yes, but only sometimes. Inherited diseases are caused by problems in parts of DNA called genes – and one of the ways that scientists are trying to treat people with these diseases, is by ‘fixing’ the broken gene with something called ‘gene therapy’.

One of the ways in which gene therapy works is by putting a normal copy of the gene in to make up for the broken one. To do this, they have to put this normal DNA into the DNA that is already there in the cells. Your DNA is very very long and complicated – it has around 25,000 genes (the important bits), and the problem with gene therapy at the moment is that scientists can’t really control where in the DNA they put their ‘normal DNA’ it’s random- if they happen to put it in the middle of a different important gene that has nothing to do with the original inherited disease, that gene can then become broken too – and cancer can develop. This has unfortunately happened before, where children were treated with gene therapy for a serious inherited disease and then developed a cancer of the blood called leukaemia. You can read more about this here: http://news.bbc.co.uk/1/hi/7149463.stm scientists are however trying to work out these problems, and hopefully we will be able to use it in the future without the risk of giving people cancer. I hope that answers your question! Please do ask more questions if you would like to know more.