Mastering the mysteries within

Mastering the mysteries within

Sylvain Comeau | While he might not have generated the press clippings of, say, Survivor's Richard Hatch last year, the media unquestionably see something special in Dr. Thomas Hudson.

	Dr. Thomas Hudson

The McGill geneticist, immunologist and allergist was named a "Great Canadian" by Maclean's and was recently singled out as one of Montreal's "Top 40 Under 40" in a Gazette/La Presse series. Now Hudson has been named Scientist of the Year 2000 by Radio-Canada's "Les années-lumière."

"Dr. Hudson has made a major contribution to the most significant scientific event of the year 2000: the sequencing of the human genome," says Yanick Villedieu, host of "Les années-lumière."

"Most years, choosing one scientist to honour is very difficult; several worthy candidates spring to mind. But this year, Dr. Hudson was an obvious choice."

The man himself is modest about the honours. "The Human Genome Project was the big story last year. I think I was chosen because of the publicity, and my availability to the media all year long," says Hudson, a professor of human genetics and immunology, and the founder and director of the McGill-based Montreal Genomics Centre.

Hudson is also assistant director of MIT's Center for Genome Research, where a group he headed made the first maps of human chromosomes in 1995 and 1996. The centre has since sequenced more than a third of the human genome. Today, with 95 per cent of the human genome already mapped, Hudson's research focuses on the realm of applications.

"Now my interest is in applying genomic information to medical genetics projects. I think that's what the whole world is doing now. We announced this year that we sequenced most of the genome, but we don't actually know what most of these genes do. So most of the people who were sequencing are now moving toward functional genomics: understanding what genes do."

The Montreal Genomics Centre is tackling medical genomics, which is the study of disease genes.

"This is a collaborative high-tech centre for about 50 different projects, on ovarian cancer, multiple sclerosis, heart disease, dia-betes, lupus, etc. The technology developed to study the human genome lends itself very well to identifying the mutant genes which are related to many diseases."

Hudson played an important role in developing that technology himself. His lab produced the "gene-chip," a tiny technological device capable of holding several thousand gene sequences that can serve as probes for the expression of particular genes in different tissues under different conditions.

Last year, Hudson earned considerable attention as a leader on a team of geneticists who uncovered the gene responsible for autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS), a disease that strikes in childhood and usually leaves its victims wheelchair-bound by their mid-forties.

The gene responsible for ARSACS is carried by an estimated one in 22 individuals in the Saguenay-Charlevoix region.

Many of the disorders under scrutiny in the Montreal Genomics Centre are inflammatory diseases, in which antibodies mistakenly attack human tissue instead of foreign invaders.

Hudson himself is currently working with graduate students on a large-scale asthma study.

"We have about 200 families in the study and we are looking at DNA markers which have been transmitted to asthmatic children. We have already narrowed it down to a region of chromosome 12, which we know has an asthma gene. Now we are studying all the genes in that region, to find the mutation which is actually involved in asthma."

Hudson says that both environment and genetics contribute to the onset of many diseases, including asthma.

"Pet dander, smoking and pollution all contribute to asthma. We tell asthmatic patients to stop smoking and get the cat out of the bedroom, but the fact remains that there are families in which a lot of people have asthma and there are families with no asthma. That's the case with hypertension, with diabetes and many other diseases."

Hudson emphasizes that his team is undertaking to corner one of the many culprits involved in the disease.

"We've learned that not everyone with asthma has the same disease. Different people have different types of asthma, and they should be treated differently depending on which one they have. It all depends on which mutant gene they inherited. Increasingly, our knowledge of genomics is helping us see that common diseases are actually different sub-types of disease."

Identifying varieties of disease based on the genetic cause will lead to increasingly tailored or targeted treatment, Hudson predicts.

"People with a particular sub-type of disease should have more tailored treatment, for example, a drug or preventative strategy which addresses the kind of asthma or hypertension that they have. That's where medicine is heading today, and that's why these projects are going on."

This approach will be a vast improvement over today's scattershot treatment methods, in which patients risk side effects by trying a medication which may or may not work.

"For example, there are about 20 hypertension drugs on the market today. Typically, only 30 per cent of patients will respond to any one drug. Why? Because they don't have hypertension for the same reason; it could be a kidney problem, a blood vessel problem, a stress problem -- or it could be their genetic background.

"If we can identify, through their genes, the underlying causes of their disease, then we don't have to treat them the same as everyone else. We can give them the treatment that that individual will respond to."