Genetic sequencing is used to find the correct order of nucleotides that make up the mutant gene.
This infomation is now stored in genetic libraries.
From this infomation, DNA probes are made and are copied by PCR.
The probes are then added to single strands of the persons DNA.
If the person has the mutant allele, then the section of the gene will show up under an X-ray.
For cancer to develop, there must be a mutated oncogene and tumour suppressor gene. Therefore people who have a history of mutated tumour suppressor genes in their familiy can be screened for the gene.
If they have this gene then they can be educated on ways to reduce their risk of getting cancer e.g. not smoking, not using sun beds, eating healthily and avoiding other mutagens.
They may also choose to take place in trials for gene therapy occuring at the moment…