14 October 2013

PARIS, France: A DNA flaw may explain why people with Type 2 diabetes are more prone to blood cancers than the rest of the population, a study said Sunday.

Doctors have long known that Type 2 diabetes is associated with leukaemia  and lymphoma, but the reasons for this have been unclear.

Researchers in France and Britain, looking at blood samples from nearly  7,500 people, including 2,200 patients with Type 2 diabetes, suggest the answer  lies in cellular mutations called clonal mosaic events (CMEs).

These are defects that result in some cells having extra copies — or,  alternatively, missing copies — of large stretches of genetic code.

Reporting in the journal Nature Genetics, the researchers said that in the  general population, CMEs are usually very rare in young people but become more  common with ageing.

Among people aged over 70, around two percent have these mutations, which  gives them a tenfold higher risk of developing blood cancer, previous research  has found.

But among people with Type 2 diabetes, CMEs were four times more common  than otherwise healthy people, the new study found. They also had a far higher  rate of kidney failure, eye disease or heart disease.

“Type 2 diabetes is a disease that accelerates ageing, so we wondered if it  would make people more likely to have these genetic defects that are associated  with ageing,” Philippe Froguel, from the School of Public Health at Imperial  College London, who led the study, said.

“This finding may partly explain why people with Type 2 diabetes are more  likely to get blood cancers.”

Froguel, who worked with counterparts from France’s National Centre for  Scientific Research (CNRS), said that, in the future, a genetic test could help  identify patients with Type 2 diabetes who are likelier to develop CMEs.

“These patients would be followed up closely to watch for early signs of  leukaemia and could start having mild chemotherapy,” he said in a press release.

According to the UN’s World Health Organisation (WHO), 347 million people  around the world have diabetes, a disease in which the body fails to break down  glucose in the blood through the hormone insulin.

Ninety percent of these have the Type 2 form of the disease, which  typically shows up in adulthood or late childhood, driven by obesity and a  sedentary lifestyle. AF

This article was first published in www.nst.com.my on 15 July 2013.