THE GENE HUNT

To call Dr Tom Hudson modest would be putting it, well, modestly. One of the world8217;s premier investigators of genetically linked disease, he discovered four years ago that DNA is inherited in chunks8212;the principle at the heart of the HapMap, the recently completed project describing millions of variations in the human genome. Yet Hudson, 44, an associate professor of medicine and human genetics at McGill University in Canada, says, 8216;8216;I was just the biologist on the team. I8217;m not the person who decided you need .1 microns here and .5 there.8217;8217;

He8217;ll admit only to having 8216;8216;a knack for engineering and gadgets8217;8217;. Hudson is much more voluble on the subject of the Human Genome Project, the 13-year effort to identify more than 20,000 genes in the human DNA lineup, which he helped make happen.

If you8217;re wondering why the project hasn8217;t produced enough drugs to stock your cabinet yet, he says, never fear: combined with information from the HapMap and tools like the ones his lab is developing now, it8217;s about to start yielding results. 8216;8216;I wanted to find genes for common diseases back in 1991, when I originally joined the Human Genome Project,8217;8217; he says. 8216;8216;But I realised quickly that the tools didn8217;t exist. If you wanted to find a gene for colon cancer and you didn8217;t know where to look, you basically had to guess.8217;8217;

The tool that8217;s now taking the guesswork out of genetics is essentially a way of examining those DNA chunks, or haplotypes, that Hudson discovered back in 2001. The HapMap drastically reduces the work scientists have to do to find out which chunks of the genome are associated with which diseases. That means the search for disease-causing genes is going to go faster than scientists could have dreamed five years ago.

8216;8216;The real explosion of information is going to happen over the next year or two,8217;8217; says Dr Francis Collins, the head of the US National Human Genome Research Institute. A lot of that information will be coming from Hudson8217;s own lab at McGill, which has already found genes involved in cirrhosis and leprosy.

His researchers8217; list of targets includes genes linked to asthma, diabetes, multiple sclerosis, lupus, tuberculosis and malaria. It8217;s also involved in a heart-attack project and a search for the genes that make some people vulnerable to cancerous tumors. Bringing treatments to the market could take many more years, maybe even decades. But then, almost everything Hudson has ever been involved with has proceeded faster than expected.