Scientists have found the genetic "brakes" which could slow down or stop diseases like multiple sclerosis and cancer.

Researchers at Edinburgh University said their findings could also lead to new treatments for such illnesses.

It was previously thought a select group of "master" genes was responsible for controlling the growth of cells which can cause the conditions.

But the study discovered that there are actually hundreds of genes which interact with each other.

Scientists said they believed variations in this network explained why people could develop diseases in different ways.

The team hopes that by identifying weak spots in the gene structure they will be able to stop the growth of tumours, enabling the growth of healthy cells.

Professor David Hume, of the University of Edinburgh's Roslin Institute, who led the study, said: "This study has effectively shown us where the brakes are which could slow down or stop diseases like cancer and multiple sclerosis. "We believe this could lead to treatments and cures for many diseases of the immune system."

A Multiple Sclerosis Society spokesman said: "Every day researchers are learning more and more about the genetic make up of MS and anything that helps put the pieces of this complex puzzle together must be a good thing.

"This study also highlights the important role that research is playing in developing our understanding of MS and other autoimmune conditions."

The findings are published in the Nature Genetics journal.