Low-cost personal genome analysis

There is an explosion in the use of techniques to find the gene variations that influence our lives. We are on the verge of a genetic revolution will be exciting, and scary.

Drs Peter Pare, Denise Daley and Andrew Sandford are professors in the Department of Medicine and investigators in the James Hogg iCAPTURE Centre.

The Human Genome Project (HGP) began in 1990 with the aim of determining the entire genetic code of one individual. It took 10 years to get the complete sequence at a cost of more than $3 billion. Today the entire genetic code of an individual can be determined in a matter of days for less than $50,000 and the cost is rapidly approaching the $1,000 goal. There is a $10 million prize called the X prize (http://genomics.xprize.org/) for the first group to develop the $1,000 genome.

One consequence of the completion of the HGP has been an explosion in the use of techniques to find the variation in genes that influence our health, including alcohol and nicotine dependence, as well as susceptibility to diseases including heart attacks, Alzheimer’s disease, osteoporosis and asthma, to name a few. These techniques are also being used to find the gene variations that influence traits such as height, eye color, skin pigmentation. The up-sides and potential down-sides of this genetic revolution are exciting and scary.

Imagine a father brings his toddler to their family physician because of recurrent croup and asks, “Does my child have asthma and is there anything I can do to prevent it?”  The family physician swabs the child’s cheek and sends the tiny sample to the lab to check the entire genome. Within days the physician can give the parents a probability that the child will develop persistent severe asthma. The physician can also predict, with modest certainty, which asthma drugs the child is most likely to respond to.

Or, consider the scenario of a 54-year-old business man who comes across the web site, 23 and Me (https://www.23andme.com/) and finds that they have a holiday special: $99 to have your entire genome scanned for all known gene variants proven to be associated with disease.  He sends in his mouthwash and within days his genetic risk profile is delivered to him online. He discovers he has a relatively rare mutation in the LRRK2 gene that raises your lifetime Parkinson’s risk to more than 50 per cent.  Later that week he is completing an application for health insurance and reads, “do you have any known risk for a chronic disease such a kidney failure, emphysema, or Parkinson’s disease?”

The possibilities of genetic advances include designer babies, not only screened to exclude mutations for devastating diseases such as cystic fibrosis, but also selected for sex, hair and eye color. DNA samples left at a crime scene may be able to create a physical description providing information about age, gender, ethnicity, hair, eye and skin colour. Pharmacogenetics will aid in determining the patients who will respond to steroids and the best choices for chemotherapy.

The ethical, legal and social impacts are broad and encompassing. One clear example is how U.S. Health Maintenance Organizations (HMOs) are now using left over blood from clinical tests to get DNA. These DNA samples are being linked to the patients’ hospital and pharmacy records to create immense bio-banks. The Bio-banks are selling access to patient samples for medical research. Ethics boards have approved this practice without patient consent provided the data is not linked to the patient name or other personal identifiers.

It is clear that genetic advances will soon give us access to large amounts of data about the possibilities in our lives. What is less clear is whether we are prepared for it.