Differences in DNA between individuals of the same species can be exploited for identification and diagnosis of heritable conditions
Techniques used to identify gene location for a variety of purposes include DNA hybridisation and DNA probes. These involve tagging a DNA strand with a fluorescent agent and binding it to a new strand, the probe, which is complementary to the target gene. The new double-stranded DNA is a hybrid.
The extent of binding to the probe (and hence the complementarity between base pairs) is measured by the intensity of fluorescence seen under UV light. This technique can be used to reveal the presence of heritable conditions, drug responses or health risks. You can get this done today!
A variety of human conditions are caused by a single gene. This means that the diagnosis of certain diseases, as well as the predisposition to them, and probability of passing them on to a child can all be found out pretty easily.
Genetic counselling can take place for couples with genetic conditions who wish to have a child and be fully informed about the risk of their child inheriting that condition – whether just carried or expressed (recessive alleles).
In cancer treatment, the presence of oncogenes can determine what course of action is most likely to provide the best outcome for the patient.