Alberta study shows DNA may not actually be good predictor of disease, health

A new study conducted at the University of Alberta suggests that genes have less to do with developing diseases than previously thought.

The study, which involved scientists examining two decades of data, concluded that DNA contribution to disease development is only about five to 10 per cent.

The data they examined looked at the relationship between common gene mutations (also known as single nucleotide polymorphisms, or SNPs) and different diseases.

Throughout the study, the U of A team put the data through simulations and modelling systems, looking for correlations in genes and disease.

“We looked at around 220 different diseases and about 590 different studies, and tried to put all that information together and determine just how much do your genes, or these SNPs, effect your likelihood or risk of getting a disease,” Wishart said.

The study did highlight some exceptions: Crohn’s disease, celiac disease and macular degeneration have a genetic contribution of approximately 40 to 50 per cent.

“Despite these rare exceptions, it is becoming increasingly clear that the risk for getting most diseases arise from your metabolism, your environment, your lifestyle, or your exposure to various kinds of nutrients, chemicals, bacteria or viruses,” Wishart said.

Wishart said that he believes that genetic testing companies like 23andMe and AncestryDNA are still reliable for finding out ancestry but that they aren’t reliable for disease risks.

“[Disease prediction] has to be taken very lightly,” Wishart said. “Our data tells us that these [DNA factors] are not important risk factors. The projected risk that they’re arguing or suggesting is often highly inflated.”