Attempting to identify individuals with high risk for certain disease is the foundation of preventive medicine. Well-known traditional risk factors are typically used to predict the disease risk in clinical settings. However, various genetic risk loci have been recently identified for the majority of common diseases, raising the possibility of utilizing these variants for risk assessment. Even though genetic factors are known to contribute to the risk of disease, information on genetic factors is neglected in most risk estimation tools.
M.Sc. Emmi Tikkanen is a Ph.D. student in the Institute for Molecular Medicine Finland (FIMM) and in Hjelt Institute, Faculty of Medicine, University of Helsinki. Her dissertation, Genetic risk profiles for coronary heart disease, was supervised by Professor Samuli Ripatti.
Genetic markers improve prediction
The contribution of genetic factors to the risk for CHD is known to be about equal to the contribution of environmental risk factors. In her thesis work, Emmi utilized the results from large-scale genome-wide association studies. These studies have identified over 40 genetic regions associated with CHD risk. Hundreds of additional loci have been shown to affect known CHD risk factors such as cholesterol levels. Using this information, Emmi constructed genetic risk scores and evaluated the genetic risk for CHD and its risk factors in over 50,000 Finnish and Swedish individuals.
Emmi’s thesis consists of four publications. In the first two she studied longitudinal effects of genetic loci associated with lipids and blood pressure, and evaluated the prediction of dyslipidemia and hypertension in young adults. In the other two, she showed that genetic risk scores predicted CHD events. The study also showed that genetic screening of individuals at intermediate risk (10-year risk 10-20%) based on traditional risk factors could be especially useful as current preventive strategies are focused mainly on the high-risk group (>20%).
To me, the most important result of this thesis is the finding that utilizing genetic information in CHD risk assessment improves the prediction over traditional risk factors and family history. By screening this intermediate risk group and targeting interventions to the group of individuals reclassified as having a high risk, hundreds or even thousands of coronary heart disease events in Finland could be prevented in 10 years.
Ain’t no Mountain High Enough
Emmi started her studies in the Faculty of Social Sciences in the University of Helsinki but eventually graduated from bioinformatics in 2010.
-The leap from social sciences to genetics was not easy but it was the right choice for me. I have truly enjoyed the collaborative and multidisciplinary atmosphere we have here in the Human Genomics wing of FIMM.
Much of her free-time during the past few years she has used for her favorite hobby, rock climbing, in many exotic places around the globe.
-When climbing you just can’t think of anything else. That’s why it is such a great counterbalance to the academic work.
Room for improvements?
Emmi‘s future plans contain more risk factor studies.
-I believe that many more genetic risk factors will be identified in the near future. It’ll be interesting to see how precise the risk predictions can be made when hundreds instead of tens of loci are known. I also believe that genetic findings will have a big role in refining disease classifications. Further research is also certainly required to learn whether informing people of their genetic susceptibility to disease motivates them to change their health behaviour to reduce their risks.
The public examination of M.Sc. Emmi Tikkanen’s doctoral dissertation, Genetic risk profiles for coronary heart disease, will take place on 8th November 2013 at 12 o´clock in the lecture hall 1, Kytösuontie 9. The opponent is Dr. Daniel MacArthur (Massachusetts General Hospital and the Broad Institute of Harvard and MIT in Boston, USA) and the custos Professor Samuli Ripatti.
Emmi Tikkanen, emmi.tikkanen[at] helsinki.fi