A 20-year, landmark study involving 10,000 participants, funded by a research group and three health-care and technology companies, Navigenics, Affymetrix Inc. and Microsoft Corp., will study long-term psychological reactions and behaviours of people undergoing genetic testing. The study which will be launched on Thursday will seek an answer to questions like: “Do gene tests improve one’s lifestyle, or one’s health?” What do people do after they learn their genetic risk levels of developing medical conditions like diabetes, cancer, or Alzheimer’s disease?” The research is designed to find out if the testing changes individuals’ lifestyle habits and helps them to eat better, quit smoking, or seek further medical evaluation and preventive strategies.

The study is expected to cost $15 million to $20 million in the first year, with the expense declining dramatically in later years, said Dr. Eric Topol, the lead researcher at the Scripps Translational Science Institute in La Jolla. The study includes Scripps, Microsoft, Affymetrix of Santa Clara and Navigenics, of Redwood City.

“Genome scans give people considerable information about their DNA and risk of disease, yet questions have been raised if these tests are ready for widespread public use,” Dr. Eric Topol said in a statement. Kevin King, president of Affymetrix, said that the study represents the largest opportunity for modern genetics “to move outside the laboratory and directly to consumers.”

Participants will complete questionnaires about their lifestyle habits at the beginning of the study before they receive information on their genetic risks. They will receive a scan of their genome and an analysis of their genetic risks for health conditions that may be changed by lifestyle like diabetes, obesity, heart attack and some types of cancer.

Navigenics Inc. will analyze the DNA of up to 10,000 Scripps Health hospital chain employees, family members and friends. Affymetrix will run the genome scan and Navigenics will provide interpretation of the results to the participants. The research will assess changes in lifestyle habits over a 20-year period. Participants will be surveyed on the lifestyle changes and health decisions they make after receiving information on their genetic risks.

Scripps hopes to complete recruitment by the end of this year and report the preliminary results as early as mid-2009.

Genetic testing identifies changes in chromosomes, genes, or proteins. The human genome is believed to contain around 20,000-25,000 genes. It includes biochemical tests for the possible presence of genetic diseases, or mutant form of the genes associated with an increased risk of developing genetic disorders. When interpreting test results, healthcare professionals consider a person’s medical history, family history, and the type of genetic test that was done.

Direct-to-Consumer (DTC) genetic testing has been controversial due to direct opposition within the scientific community. Earlier this year, The California Department of Public Health ordered Navigenics and several similar operators to stop doing business in California. The main reason was that the company lacked a state laboratory licence. In August the company received a licence. Critics of DTC testing argue against the risks involved and say that many DTC testers make unsubstantiated claims. Without professional guidance, consumers can potentially misinterpret genetic information and the benefits risks, and limitations of a particular test.