KIAA0350 gene triggering juvenile diabetes

15 July, 2007:

A team of scientists in the United States and Canada say they have unearthed a gene variant that is believed to increase a child’s risk for Type 1 diabetes. The study has been published in the advanced online publication of the journal Nature.

Type 1 diabetes, commonly called juvenile diabetes because it mostly begins in childhood, is an autoimmune disease where the immune system destroys the insulin-producing beta cells in the pancreas. In other words, it is the condition in which the body attacks itself, destroying the pancreatic beta cells that the body needs to regulate blood sugar or glucose. The cells in the pancreas produce insulin, the hormone that regulates blood glucose.

Type 1 diabetes is fatal unless patients get frequent doses of insulin by injection to keep the body’s blood sugar under control.

More and more scientists are investigating the genetics of Type 1 diabetes and they hope that the new discovery would lead to ways to prevent and treat the disease.

Dr Constantin Polychronakos, director of Pediatric Endocrinology at McGill University in Montreal, Canada, and senior author of the study, said it may one day be possible to predict which children are at high risk of Type 1 diabetes by screening babies when they are born.

Since the unravelling of the human genome a few years ago, a new method called genome wide association (GWA) has emerged, where specialists in genetic research scan the DNA of patients and search over 500,000 genes for markers of disease.

In the new study, paediatrics researchers at the Children’s Hospital in Philadelphia, the United States, and McGill University, Canada, conducted such a search and discovered a new gene called KIAA0350, which sits on chromosome 16 that appears to play an important role in the development and maintenance of Type 1 diabetes.

The researchers are carrying on with the project because they think that this gene is only one of many that work together to wipe out the insulin-producing cells. There could be as many as 15 or 20 genes.

Dr Hakon Hakonarson, director of the Center for Applied Genomics at The Children’s Hospital of Philadelphia and lead author of the study, said the genotyping technology available now has revolutionised the way research is done. “Unlike the previous technology, which was quite limited and dealt largely with relatively rare gene variants,” added Dr Hakonarson, “we can now detect common genetic variants that are important in large numbers of individuals, and begin to understand how multiple genes interact in complex diseases such as diabetes.”

The researchers – who had access to DNA samples of patients and their families attending paediatric diabetes clinics in Philadelphia in the US, and four cities in Canada – scanned the genomes of 1,046 children with Type 1 diabetes for the study.