20-year study to assess impact of genetic testing

A consortium of health care, technology and research leaders have joined forces in a first-of-its-kind research study to assess the behavioural impact of personal genetic testing on people who choose to receive such screenings to identify their potential risk for developing certain diseases.

Sponsored by Scripps Translational Science Institute (STSI), the study aims to find out if participating in personal genomic testing will improve health by motivating people to make positive lifestyle changes, such as exercising, eating healthy and quitting smoking, as well as decisions to seek further medical evaluation and preventive strategies. The study will offer genetic scans to up to 10,000 employees, family members and friends of the nonprofit Scripps Health system in San Diego, US, and will assess changes in participants’ behaviours over a 20-year period.

Study participants age 18 and older can receive a scan of their genome and a detailed analysis of their genetic risk for more than 20 health conditions that may be changed by lifestyle, including diabetes, obesity, heart attack and some forms of cancer.

“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,” said Eric J. Topol, MD, director of STSI and principal investigator of the study. “Our study will prospectively evaluate the effect that state-ofthe- art gene scans have on people’s lifestyles, behaviours, diets and psyches.”

Lifestyle changes will be tracked via participants’ selfreported health assessment questionnaires, including a baseline assessment and subsequent self-reported assessments at three- and 12- month intervals after receiving gene scan results. Researchers will also ask participants to conduct periodic health surveys over the next 20 years to assess their behaviours longitudinally. A complete database of genomic and clinical information will be assembled at the Scripps Genomic Medicine programme.

“We stand upon the threshold of a fundamental paradigm shift from reactive to predictive and preventive medicine,” said Vance Vanier, MD, Chief Medical Officer of Navigenics, a co-sponsor of the study. “Modern genomic tools are instrumental in this shift and studies that help inform physicians about the most responsible, ethical and effective ways to help people use this information to have impact on their health are crucial.”

Gene implicated in AMD identified

Scientists have identified one of the genes implicated in age-related macular degeneration, the most common cause of blindness in developed countries.

The research, published online in the Lancet, adds to the growing understanding of the genetics of age-related macular degeneration (AMD), which the researchers believe should ultimately lead to novel treatments for the disease.

Almost two-thirds of people aged 80 years or older are affected by AMD to some degree, with more than one in ten left blind by the disease. Researchers have previously identified a number of other genes or genetic loci (regions of the genome) which affect a person's susceptibility to the disease. Researchers at the University of Southampton have shown that a particular variant of the gene SERPING1 appears to offer protection against the disease.

The University of Southampton team and colleagues from the University of Iowa found evidence of proteins expressed by SERPING1 in the retina and the choroid layer (the vascular layer next to the retina), the two areas affected by AMD. These proteins are involved in regulating a part of the body's innate immune system known as the “complement system”. The findings suggest that the complement system is malfunctioning, attacking the retina and choroid layer.

Cancer Genome Atlas reports results for brain cancer study

The Cancer Genome Atlas (TCGA) Research Network, a collaborative effort funded by the US National Cancer Institute (NCI) and the US National Human Genome Research Institute (NHGRI) of the US National Institutes of Health (NIH), reported the first results of its large-scale, comprehensive study of the most common form of brain cancer, glioblastoma (GBM).

In a paper published 4 September 2008, in the advance online edition of the journal Nature, the TCGA team describes the discovery of new genetic mutations and other types of DNA alterations with potential implications for the diagnosis and treatment of GBM.

Among the TCGA findings are the identification of many gene mutations involved in GBM, including three previously unrecognised mutations that occur with significant frequency; and the delineation of core pathways disrupted in this type of brain cancer. Among the most exciting results is an unexpected observation that points to a potential mechanism of resistance to a common chemotherapy drug used for brain cancer.

The work complements and expands upon a parallel study by Johns Hopkins researchers of 22 GBM tumours, which was also published 4 September 2008 in the journal Science.

GBM, which is the type of brain cancer most often found in adults, is a very fast-growing type of tumour. Most patients with GBM die of the disease within approximately 14 months of diagnosis.

As in the Human Genome Project, TCGA data are being made available to the research community through a data base: http://cancergenome.nih.gov/dataportal 

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