By Michael Mackley
It took nearly thirteen years and an army of scientists to generate the first sequence of the human genome. Now, patients around the world are having their genomes sequenced every day. Since the first sequence was unveiled in 2003, the cost of whole-genome sequencing (WGS) has dropped from almost $1 billion to less than $1,000—allowing WGS to enter routine clinical care, potentially transforming the way we diagnose and treat disease. Large national initiatives to read individuals’ genomes are helping to drive this transition; the UK’s NHS England is currently sequencing 100,000 genomes, and the USA has plans to sequence 1 million genomes in the near future. A 2015 study predicts that up to 2 billion people worldwide could have their genomes sequenced within the next decade—comparable to the current reach of the Internet. With so many genomes to be sequenced, it is imperative that laws and policy ensure that individuals, and society, are protected from harm. While larger pieces of legislation—such as those protecting against discrimination—are needed internationally, guidance and policies around routine management are also required.
One area of particular concern is that of ‘secondary’ (or ‘incidental’) findings. While WGS provides a valuable opportunity to learn about genetic contributions to disease (‘primary’ findings), it can also reveal genetic information that may not be relevant to the health condition affecting the patient or their family. This includes genetic changes associated with other health conditions—ranging from medically actionable findings, such as genetic predispositions to breast cancer where treatment is available, to non-actionable findings, such as genetic changes associated with an increased risk of Alzheimer’s. The American College of Medical Genetics and Genomics published recommendations suggesting a moral obligation to seek and return actionable secondary findings, fueling significant debate (1,2). Medical Genetics organizations from other countries (including Canada and Europe) have published more conservative guidelines restricting generation of secondary findings, at least until more evidence is available to support (or refute) clinical utility and assess wider impacts. Continue reading