Genetic and genomic testing bring many benefits to patients, but there may be pitfalls for doctors, as Dr Kathryn Leask explains.

Genetic testing has been part of patient care for many years. Where appropriate, it allows diagnoses to be confirmed, including those made antenatally, as well as predictive testing of patients for conditions such as breast cancer and Huntington’s disease. Carrier testing allows parents to have some control over their reproductive choices, particularly where they may have had a child previously affected by an inherited condition, such as cystic fibrosis.

While the use of genetic testing arms healthcare professionals and patients with information that will help them make choices about their care and about risks to their family, it has its own unique legal problems. With great emphasis now being placed on the importance of genetic and genomic testing in many areas of medicine, it is important that all healthcare professionals are aware of the potential pitfalls.

New generation testing … may also bring up unexpected results and those which were not anticipated…

Traditional genetic testing often involves looking for single gene mutations in order to establish whether or not a patient has a particular genetic condition or whether they are a carrier, which may put them or their offspring at risk. New generation testing, genomic testing, analyses a patient's whole genome, and may identify more than the relevant mutated gene - it could also bring up unexpected results, including those not anticipated, specifically ordered or discussed with the patient. These need careful interpretation and a decision needs to be made whether or not they should be communicated to the patient.

There are a number of areas where legal issues may arise as a result of genetic testing.


Diagnosing genetic conditions does not always involve performing laboratory tests in order to confirm the diagnosis. A patient's phenotype may indicate that a genetic condition is present and therefore diagnosis may depend on a physical examination or, in the case of prenatal testing, an in-utero ultrasound scan. Failure to diagnose a patient, either by failing to identify relevant characteristics on examination or failure to identify or interpret genetic results, could lead to legal action. This may occur where abnormalities are not picked up, for example, or where the significance of them is not recognised.

In the case of prenatal testing, this may deny prospective parents the opportunity to make reproductive decisions about their pregnancy, such as whether or not to opt for a termination, or it may prevent them from appropriately preparing for the birth of a disabled child. In other situations, failure to make a diagnosis may result in patients not being screened appropriately or being offered preventative surgery - for example, those patients with genetic mutations which predispose them to developing certain types of bowel and breast cancer.