Blood samples revealed ‘startling differences’ in the biochemistry of sheep carrying the HD gene.

Research uncovers biomarkers for illness before symptoms begin
 
Scientists say they have identified early warning signs of Huntingdon’s disease in sheep carrying the human HD mutation, suggesting the illness affects the body long before physical symptoms appear.

The research, carried out by the Universities of Surrey and Cambridge and published in Scientific Reports, could offer new insights into this devastating illness in humans.

Huntingdon’s disease is a genetic neurodegenerative disorder that affects more than 6,700 people in the UK. There is no cure, and patients typically die 10-25 years after diagnosis.

Researchers found metabolic changes in five-year-old sheep carrying the HD gene. Up until this point, the animals had shown no signs of the illness.

Blood samples revealed ‘startling differences’ in the biochemistry of sheep carrying the HD gene, compared to normal sheep. There were significant changes in 89 out of 130 metabolites measured in the blood, with increased levels of amino acids, arginine and citrulline, and decreased levels of sphingolipids and fatty acids that are commonly found in brain and nervous tissue.

Researchers say the alterations in metabolites suggests that the urea cycle and nitric oxide pathways, which are both vital body processes, are dysregulated in the early stages of Huntingdon’s disease. The identification of these biomarkers could help to track the disease in pre-symptomatic patients, and could help researchers to come up with strategies to address the biochemical abnormalities.

Professor Jenny Morton from the University of Cambridge said: “Despite its devastating impacts on patients and their families, there are currently limited treatments options, and no cure for Huntington’s disease. The development of objective and reliable biomarkers that can be rapidly measured from blood samples becomes immeasurably important once clinical trials for therapies begin.

“The more we learn about this devastating illness the better chance we have of finding a cure.”