Genetics could drive a new wave of medicalisation if genetic tests are accepted without appropriate clinical evaluation

In the public imagination genetic science has already brought us close to a world in which tests and cures are available for most diseases. The immediate prospects are, however, decidedly more prosaic. With the exception of the relatively rare high penetrance, single gene disorders, genetic tests differ little from most other medical tests, providing evidence of statistical risk only. Inflated perceptions of the value of specific genetic tests could drive a wave of inappropriate medicalisation. Genetic claims, tests, and treatments, like others, should be subjected to evaluation to establish their clinical usefulness, so that doctors and patients can act on sound evidence.

The term “genetics” conveys two different concepts: genetics as the study of inherited characteristics, and genetics as the study of cellular processes controlled by DNA. DNA codes lie at the centre of the biological processes in all living cells and generate the protein building blocks for cellular activity. Variations in coding abound between people. The differences occasionally derive from variations in a single gene, but much more typically they derive from the interacting effects of many genes. DNA is no blind cipher, but part of a modulating system interacting with cellular mechanisms and environmental factors, that together time and modify the expression of proteins within the cells that make up the human organism.1

In the public mind, high …