Entire gene networks involved in susceptibility to obesity

Many gene studies focus on WHICH genes cause a person’s risk of developing a disease (forward genetics) but few focus on HOW those genes can lead to disease.  Researchers at Merck and Co, deCODE genetics and academic centres in the US and France have focused on the latter and shed light on the complexity of common disease causes where multiple genetic changes are involved (functional genetics).

Two studies analysed DNA variations, patterns of gene expression in disease tissue, and clinical data on a large scale to identify which gene networks linked to metabolic disorders (a range of symptoms that are thought to cause obesity, diabetes and atherosclerosis or heart disease).

The first study on mouse livers looked at finding genes that might be linked to obesity, diabetes and heart disease.  The researchers created gene networks and located highly connected sub-networks of core genes that were known to be linked to obesity, diabetes and heart disease. They also identified, and validated at the experimental level, three new genes thought to cause obesity: Lpl, Pmp1l and Lactb.

The second study on over 1,000 human blood and fat tissue samples from Iceland, and using data from the first study, created a gene expression network of human obesity traits.  This human obesity network showed considerable overlap with the mouse network.

The researchers concluded that:

“A core network module in humans and mice was identified that is enriched for genes involved in the inflammatory and immune response and has been found to be causally associated to obesity-related traits.”

The next question is WHY?

Elaine Warburton  www.geneticsandhealth.com