Breakthrough in tracing trigger for migraines

Glaxo Wellcome is on the verge of finding the genes that make some people more susceptible to three common illnesses, the pharmaceutical giant announced yesterday.

Glaxo Wellcome is on the verge of finding the genes that make some people more susceptible to three common illnesses, the pharmaceutical giant announced yesterday.

A revolutionary approach to finding the "signposts" on the genome map - the digital recipe encoded in human chromosomes - has located genes linked with migraines, diabetes and psoriasis, the debilitating skin disorder.

Scientists thought that finding the predisposition genes for human diseases would take far longer and involve a more painstaking search of the genome but the British company said a new approach was making the discovery easier.

Allen Roses, vice-president and director of genetics at Glaxo, released its findings at the annual meeting of the American Society of Human Genetics in San Francisco. "These are critical findings. We can narrow the search for susceptibility genes to a small region ... of DNA known to be linked to particular disease. This is a very important finding," Dr Roses said.

"The research we are reporting on does not mean that we can provide cures for these diseases overnight but it certainly provides us with a much better understanding of the genes involved. In the very near future we hope to understand which gene or genes make some people susceptible to these common debilitating diseases. Genetic studies of this type are extremely important in investigating the factors that underlie the development of illnesses, and revealing their root causes."

Glaxo, like many other companies and organisations involved in the human genome project, has concentrated much of its recent effort on the smallest genetic variations that distinguish one individual from another, known as single nucleotide polymorphisms (SNPs, pronounced "snips").

There is, on average, one SNP in very 1,000 "letters" of the 3 billion letters of the human genetic code. By finding SNPs, scientists are able to discover the tiniest genetic differences that may indicate why some people inherit predispositions to, say, heart disease, while others do not.

Dr Roses said that comparing the SNP map from a group of people with a certain disease with other people who do not have it enables scientists to focus on the small section of DNA that is likely to contain the gene related to that disease.

Glaxo Wellcome said it is this technique that has enabled it to identify the small regions of the human genome which seem to be involved in conferring susceptibility to migraine, diabetes and psoriasis.

"Understanding how different forms of these genes contribute to disease will help us in designing new medicines for both prevention and potential cure for these conditions," Dr Roses said.

Glaxo Wellcome announced six months ago that it had formed an international consortium with nine other companies and five academic institutions to build up a map of genetic signposts made from 300,000 SNPs. The consortium intends to publish the research on the Internet to prevent other organisations from patenting the discoveries.