March 5, 2013 (Toronto) - Some of the dramatic differences seen among patients with
schizophrenia may be explained by a single gene that regulates a group of other
schizophrenia risk genes. These findings appear in a new study from the Centre
for Addiction and Mental Health (CAMH).
The study revealed that people with
schizophrenia who had a particular version of the microRNA-137 gene (or MIR137),
tended to develop the illness at a younger age and had distinct brain features
- both associated with poorer outcomes - compared to patients who did not have
this version. This work, led by Drs. Aristotle Voineskos and James Kennedy,
appears in the latest issue of Molecular Psychiatry.
Treating schizophrenia is
particularly challenging as the illness can vary from patient to patient. Some
individuals stay hospitalized for years, while others respond well to
"What's exciting about this
study is that we could have a legitimate answer as to why some of these
differences occur," explained Dr. Voineskos, a clinician-scientist in
CAMH's Campbell Family Mental Health Research Institute. "In the future,
we might have the capability of using this gene to tell us about prognosis and
how a person might respond to treatment."
"Drs. Voineskos and Kennedy's
findings are very important as they provide new insights into the genetic basis
of this condition that affects thousands of Canadians and their families,"
says Dr. Anthony Phillips, Scientific Director at the Canadian Institutes of
Health Research Institute of Neurosciences, Mental Health and Addiction.
Also, until now, sex has been the
strongest predictor of the age at which schizophrenia develops in individuals.
Typically, women tend to develop the illness a few years later than men, and
experience a milder form of the disease.
"We showed that this gene has a
bigger effect on age-at-onset than one's gender has," said Dr. Voineskos,
who heads the Kimel Family Translational Imaging-Genetics Research Laboratory
at CAMH. "This may be a paradigm shift for the field."
The researchers studied MIR137
— a gene involved in turning on and off other schizophrenia-related genes — in
510 individuals living with schizophrenia. The scientists found that patients
with a specific version of the gene tended to develop the illness at a younger
age, around 20.8 years of age, compared to 23.4 years of age among those
without this version.
"Although three years of
difference in age-at-onset may not seem large, those years are important in the
final development of brain circuits in the young adult," said Dr. Kennedy,
Director of CAMH's Neuroscience Research Department. "This can have major
impact on disease outcome."
In a separate part of the study
involving 213 people, the researchers used magnetic resonance brain imaging
(MRI) and diffusion tensor-MRI (DT-MRI). They found that individuals with the
particular gene version tended to have unique brain features. These features
included a smaller hippocampus, which is a brain structure involved in memory,
and larger lateral ventricles, which are fluid-filled structures associated
with disease outcome. As well, these patients tended to have more impairment in
white matter tracts, which are structures connecting brain regions, that serve
as the information highways of the brain.
Developing tests that screen for
versions of this gene could be helpful in treating patients earlier and more
"We're hoping that in the near
future we can use this combination of genetics and brain imaging to predict how
severe a version of illness someone might have," said Dr. Voineskos.
"This would allow us to plan earlier for specific treatments and clinical
service delivery and pursue more personalized treatment options right from the
This research was funded by the
Canadian Institutes of Health Research, the Brain & Behavior Research
Foundation and the Ontario Mental Health Foundation.
The Centre for Addiction and Mental
Health (CAMH) is Canada's
largest mental health and addiction teaching hospital, as well as one of the
world's leading research centres in its field.
Michael Torres; (416) 595-6015; email@example.com.
CAMH combines clinical care,
research, education, policy development and health promotion to help transform
the lives of people affected by mental health and addiction issues. CAMH is
fully affiliated with the University
of Toronto, and is a Pan
American Health Organization/World Health Organization Collaborating Centre.
For more information, please visit www.camh.ca.
The Canadian Institutes of Health
Research (CIHR) is the Government of Canada's health research investment agency.
CIHR's mission is to create new scientific knowledge and to enable its
translation into improved health, more effective health services and products,
and a strengthened Canadian health care system. Composed of 13 Institutes, CIHR
provides leadership and support to more than 14,100 health researchers and
trainees across Canada.