Date:03/06/2006 URL: http://www.thehindu.com/2006/06/03/stories/2006060305521100.htm

Opinion - News Analysis

New test offers speedy reading of genetic make-up

Ian Sample

Sequences will reveal what chance we have of developing an endless variety of diseases.

AMERICAN SCIENTISTS have ushered in an era of personalised genetics by reading an individual's entire genetic make-up in record time. Researchers used a new technique called DNA barcoding to scan six feet of unravelled genetic material plucked from a single cell of a donor in two weeks. The Human Genome Project, which produced the first draft of the human genetic code in 2000, took three years to complete.

The feat marks the beginning of a dramatic shift in medicine that will allow people to gaze upon the 6 billion letters that form their unique biological blueprint for the first time. David Schwartz, a professor of genetics at the University of Wisconsin, Madison, will describe the research at the Human Genome meeting in Helsinki on Saturday. Within three years, he believes his lab will have a test capable of reading an entire genome within an hour for less than $100. Researchers believe that individualised genetic printouts will radically improve patients' lives by allowing doctors to give them personalised advice on their diets, lifestyles and medical check-ups.

Amid the strings of Gs, Ts, Cs and As that make up a human genome are sequences that reveal not just the colour of our eyes and hair, but where we came from and what chance we have of developing an endless variety of diseases and mental impairments. But Dr. Schwartz admitted patients would need counselling before they are shown the genetic hand they have been dealt. But moves to use genetic information from individuals could face stiff opposition from groups who fear the information could fall into the wrong hands. "We don't want to see it abused in any way, for example by insurance companies," Dr. Schwartz said.

To read a whole genome, Dr. Schwartz plucks strands of DNA from a cell and stretches them out on a sheet. He then squirts on an enzyme that cuts the DNA whenever it encounters a specific sequence of letters. Studying the barcode-like pattern produced by the cuts helps identify which letters, or DNA bases, are where. —