Biopeer

Gene studies bring new hope

Diabetes research got a boost when an international research team pinpointed four points on the human gene map that are linked to type 2 diabetes. Researchers from the Imperial College London, UK, McGill University, Canada and the Pasteur Institute of France, among other institutions, together examined 392,935 single nucleotide polymorphisms (SNPs) belonging to participants with and without type 2 diabetes. After extensive comparisons, the researchers narrowed down the points or loci to four. The loci were those concerned with insulin regulation, including a mutation of zinc transporter SLC30A8. The scientists are hopeful that these findings will help them find a way to confirm a person’s predisposition to diabetes and thereby prevent its occurrence by suggesting dietary and other lifestyle changes.

Meanwhile, researchers from the Breast Cancer Association Consortium have confirmed that the gene CASP8 reduces the risk of breast cancer. After examining SNPs from nine genes, they concluded that a variation in the CASP8 gene reduced the risk for women carrying it by 10 per cent. On the other hand, a variation in the TGF-beta1 gene raised the risk of developing the disease by 7 per cent. Both these variants are not very strong and have as much influence as lifestyle habits do. However, the researchers admit the possibility of other genes existing that may be weak by themselves but can collectively influence one’s chances of developing the disease.

In another study, researchers from the University of California, San Francisco, Children's Hospital in California have determined that a protein secreted by gene Olig2 causes gliomas to form. They conducted experiments on mice where they observed that when the protein was prevented from functioning, the gliomas also stopped developing in 91 per cent of the mice. They believe that drugs that target Olig2 will be able to destroy tumor cells without having any negative effect on healthy brain tissue.

Powered by Qumana

New DNA map to trace genetic ills

In a crucial achievement that will help researchers trace genes that promote common illnesses such as heart disease, cancer, asthma and diabetes, a team of scientists has published the first map of human genetic variations. By studying the DNA of 269 people from Nigeria, Japan, China and the United States, they have mapped patterns of tiny DNA differences, the subtle genetic changes, which make each of us different.

Genes that predispose people to common disorders are extremely hard to find. In the past, researchers have had to sift through the entire three billion individual chemicals that comprise the human blueprint to search for disease-causing genes. But the new ‘HapMap’ opens the door to comprehensive searches through the human DNA for those genes. Now by focusing on haplotypes, researchers are able to reduce the number of sites that must be searched to a much more manageable one million, sharply speeding up the search for genetic change.

Such understanding is required to work out diagnosis, prediction and treatments of diseases. The genes give pointers to the biological underpinnings of disease, and suggest strategies for developing therapies. Researchers studying complex diseases, like diabetes, which are affected by many genes as well as environmental factors, will compare the haplotypes of individuals with the disease to those without. Finding haplotypes linked to the disease may narrow down the search for the genetic variations, or SNPs responsible.

This development will help academics and biopharma companies better use the open-source HapMap to relate human genetic variation to diseases and to patients’ differential response to medicines, a key part of the trend towards treatment more specifically targeted to individuals’ biological characteristics. In fact, a person’s DNA could be decoded at an early age to check predisposition to any illness and then counter the risk of the disease.

If the genome sequence is the road map of the human DNA landscape, then the HapMap could very well serve as a map of the potholes on the road that would provide the vital signs of danger.