Genetic link between mental disorders, diabetes found

There may be a genetic connection between type 2 diabetes and mental disorders such as schizophrenia, bipolar disorder and some forms of depression, a new study has found.
Researchers showed that a gene called 'DISC1,' which is believed to play a role in these mental health disorders, influences the function of pancreatic beta cells which produce insulin to maintain normal blood glucose levels.
"Studies exploring the biology of disease have increasingly identified the involvement of unanticipated proteins - DISC1 fits this category," said Rita Bortell from the University of Massachusetts Medical School in US.
"Our hope is that the association we have found linking disrupted DISC1 to both diabetes and psychiatric disorders may uncover mechanisms to improve therapies, even preventative ones, to alleviate suffering caused by both illnesses which are extraordinarily costly, very common, often quite debilitating," she added.

Researchers studied the function of DISC1 by comparing two groups of mice. The first group was genetically manipulated to disrupt the DISC1 gene only in the mouse's pancreatic beta cells.
The second group of mice was normal. The mice with disrupted DISC1 gene showed increased beta cell death, less insulin secretion and impaired glucose regulation while control mice were normal.

Researchers found that DISC1 works by controlling the activity of a specific protein (GSK3B) already known to be critical for beta cell function and survival.
Inhibition of GSK3B resulted in improved beta cell survival and restored normal glucose tolerance in mice with disrupted DISC1.

Alterations in the DISC1 gene were originally associated with increased risk of schizophrenia, but further studies found DISC1 alterations in individuals with bipolar disorder and major depression.
The study was published in the FASEB Journal.