Human genome mapping a failure in finding cures for disease

Thursday, October 07, 2010 by: David Gutierrez, staff writer
Tags: human genome project, cures, health news

(NaturalNews) Ten years ago, President Bill Clinton announced that the complete human genome had been successfully mapped, and Francis Collins of the National Institutes of Health predicted genetic diagnosis of disease within a decade.

"Over the longer term, perhaps in another 15 or 20 years," Collins said then, "you will see a complete transformation in therapeutic medicine."

Yet 10 years later, genetic diagnosis of disease remains a distant dream, and many of the supposed genetic predictors of disease risk are being debunked one by one.

After the mapping of the genome, the National Institutes of Health initiated a $138 million project to map all the common gene variants among people of African, European and East Asian descent. The underlying theory was that because diseases such as diabetes, cancer and heart disease are so common, the gene variants that contribute to them should be common as well. Once these sites had all been mapped, researchers proceeded to test for correlations between given variants and common diseases.

By 2009, 400 different variants had been linked with various diseases; today, the number is 850. Yet studies are now showing that these variants explain very little of the genetic component of disease risk.

One recent study, conducted by researchers from Brigham and Women's Hospital and published in the Journal of the American Medical Association, found that 101 different gene variants linked to heart disease risk had precisely zero predictive benefit in 19,000 women over the course of 12 years. In contrast, a traditional family history survey was significantly predictive.

Part of the problem, researchers say, is that the genetic contribution to disease now appears to come from a larger number of more rare variants, rather than a few common ones as previously thought. In addition, many common diseases such as cancer, diabetes and heart disease are far more influenced by environmental than by genetic factors.

"Genomics is a way to do science, not medicine," incoming National Cancer Institute president Harold Varmus said.

Sources for this story include: http://www.nytimes.com/2010/06/13/health/res....