A predictive genetic test is a genetic test in a person without symptoms to predict future risk of disease. This testing allows early identification of individuals at risk of a specific condition, which can lead to reduced risk through targeted screening and prevention. For example, a woman who is found to have a BRCA1 or BRCA2 gene is at increased risk of breast cancer. She might be offered regular breast screening, or even preventative surgery, to help reduce her risk.
The value of a predictive test depends on the nature of the disease for which testing is being carried out, how effective treatment is, and the cost and efficacy of screening and surveillance measures.