Genes for type 2 diabetes identified

Researchers at the McGill University Health Centre (MUHC) have identified four genes, which increase the risk of developing type 2 diabetes.

The study, published in the journal Nature, was led by MUHC endocrinologist Dr Rob Sladek at the McGill University and Genome Quebec Innovation Centre together with Dr Constantin Polychronakos at the MUHC and Dr Philippe Froguel at the Pasteur Institute in France. The study also involved scientists at theUniversity of Montreal, Imperial College London and the Montreal Diabetes Research Centre.

Sladek and his colleagues searched the entire human genome to identify genes which predisposed individuals to developing diabetes. By comparing hundreds of thousands of DNA fragments from diabetes patients with those from non-diabetic individuals, the team discovered that patients who developed diabetes shared common gene variants on chromosomes 8, 10 and 11.

"Of the four genes we have identified, two are involved in the development or function of insulin-secreting cells and one plays a role in the transport of zinc, an important mineral required for the production of insulin," said Sladek.

"We used a totally new concept and technology to look for the genes," added Polychronakos. "It worked very successfully and our findings are proof of principle that these approaches can be used to dissect the genetic component of other complex diseases and, eventually, other complex human traits."

Type 2 diabetes is the most common form of diabetes and is caused by the decreased production or effect of insulin, a hormone secreted by the pancreas, which regulates the amount of glucose in the blood. The group's new finding helps identify the population at the highest risk of developing this disease.

The research was funded by a grant from Genome Canada and Genome Quebec headed by Dr Barry I Posner, professor of Medicine at McGill University and the MUHC, as well as a grant from the Canadian Foundation for Innovation to the Montreal Diabetes Research Centre, headed by Dr Marc Prentki, professor of Medicine at the University of Montreal.

"In the last few years, advances in technology pioneered in Quebec, have made complex genetic analyses, such as those used in this study, possible," stated Genome Quebec President Paul L'Archeveque. "Without these advances an the collaboration between institutes, this research would not have been possible. The experimental approach used in this study, may help lead to the unravelling of other complex genetic diseases."

Diabetes affects approximately 170 million people worldwide and is increasing, with the World Health Organisation (WHO) predicting 300 million diabetics by 2025. According to a Visiongain report, the global diabetes drugs treatment market was valued at USD 15 billion in 2005. Oral anti-diabetics were the leading category of drugs valued at USD 8.2 billion, up 6.3 per cent on total global sales in 2004. Total sales for insulin products increased by 16.5 per cent to reach total global sales of USD 6.8 billion in 2004.