A new link has been established between high levels of cholesterol in the brain and Huntington's disease.
Researchers from the Mayo Clinic in Minnesota claim that tests have shown that the mutated Huntington's protein, which causes the disease, reacts with another protein to produce large deposits of cholesterol in the brain.
It is hoped that the findings, which are published in the Human Molecular Genetics journal, will help scientists establish new early-stage tests for the disease, which is hereditary.
"Our discovery that the mutant Huntington's disease protein derails the cholesterol delivery and causes cholesterol accumulation in neurons provides us with key results and solid clues to the mechanism of this disease," said molecular biologist Cynthia McMurray.
"Fully understanding the mechanism of toxicity is the key to developing treatments."
It is thought that around half of those that carry the disease without any sign of symptoms will pass it on to their children.