Population-wide gene testing has limited ability to predict disease

genome graphic - Testing a population for multiple genes at once will be limited in its ability to accurately predict disease risk, argues a new paper involving UCL's Professor Aroon Hingorani. DNA sequence commonly varies between individuals at many different points throughout the genome. Some of these genetic variants influence individual risk of common diseases such as dementia, cancer, diabetes, and cardiovascular disease, through effects on the expression or function of the encoded proteins. The effects of these variants on disease risk in any individual can be summarised by generating a polygenic risk score. Strong claims have been made about the transformative potential of polygenic risk scores for prediction, prevention, and early detection of disease and such testing has attracted the interest of policy makers and the commercial sector. However, in an analysis article in the British Medical Journal , clinical researchers from UCL, The Institute of Cancer Research, London, and the University of Oxford argue that the predictive performance of such tests is limited. Co-author Professor Aroon Hingorani (UCL Institute of Cardiovascular Science), who is also Cardiovascular Theme Lead for the UCLH NIHR Biomedical Research Centre and a Consultant in Internal Medicine at UCLH, said: "Population-wide 'polygenic scoring' is inherently limited because many cases of disease occur among people who do not have high polygenic scores and many of those with high polygenic scores do not develop disease." NHS genetic testing currently focuses on a small number of well-understood disease mutations which strongly raise the risk of disease - such as BRCA1 and BRCA2 in breast and ovarian cancer.