Genes 'linked to multiple diseases'
Single genes can be linked to multiple diseases such as cancer and heart conditions, scientists in Edinburgh have discovered.
The Edinburgh University research suggested that one in five genes were linked to more than one disease.
The study found genes responsible for Crohn's disease were linked with other conditions.
They included breast and prostate cancer, Hodgkin's lymphoma, high cholesterol and obesity.
The researchers said people who carry particular genes - including some responsible for heart disease, Parkinson's disease and some cancers - could be at risk of developing other health problems.
Knowing how diseases are genetically connected could aid efforts to develop medicines and could help predict and avoid potential side-effects.
Dr Evropi Theodoratou, of Edinburgh University's centre for population health sciences, said: "Showing that genes are linked to more than one disease is very important.
"We have shown that this is a common finding and not just an exception.
"Anyone who goes for genetic testing should be aware that in future any information they receive about individual genes could have wider implications than they or the clinician immediately realise.
"They could also influence the risk of other conditions, so being aware of these wider effects is important."
The scientists also report new genetic links between those genes associated with certain fats that may lower cholesterol and the risk of gallstones.
And the study supports earlier research that identified a link between fetal haemoglobin and risk of malaria.
The study is published online in the American Journal of Human Genetics.
The analysis used data from the National Human Genome Research Institute's catalogue of published genes which influence risk of common diseases.