An international research study led
by researchers from the Universities of Helsinki and Oxford has
identified a genetic variant that protects against type 2
Type 2 diabetes affects over 1.1 million Australians and more
than 400 million people worldwide so understanding the genetic
causes and links is important to future healthcare.
One of the genetic factors associated with type 2 diabetes is a
variation in a gene called SLC30A8, which encodes a protein which
carries zinc. This protein is important, because zinc is essential
for ensuring that insulin has the right shape in the beta-cells of
Researchers have known for many years that changes in this gene
can reduce the risk of getting type 2 diabetes, but not how or why
it happened. Researchers recruited members from families with a
rare mutation in the SLC30A8 gene to join a study to test how they
respond to sugar in a meal.
A strength of this approach is that the researchers could study
entire families and compare people with the mutation with relatives
who don't have it, but who have similar genetic background and
Dr Tiinamaija Tuomi, who co-led the study said, "This way, we
could make sure that the effects we were seeing were definitely
because of this gene, and not because of another genetic or
Results showed that people with the mutation have higher insulin
and lower blood sugar levels, reducing their risk for diabetes.
An international collaboration of 50 researchers also studied
pancreatic cells with and without the mutation in the lab, and
carried out experiments in mice and human cellular material to
understand exactly what was happening when the function of the
SLC30A8 gene changed.
Dr Benoit Hastoy, from Oxford Universities Centre for Diabetes,
Endocrinology & Metabolism, said "We found that this mutation
had collateral consequences on key functions of pancreatic beta
cells and during their development."
"Importantly, this study exposes the
extraordinary molecular complexity behind a specific gene variation
conferring risk or protection from type 2 diabetes."
"Taken together, the human and model system data show enhanced
glucose-stimulated insulin secretion combined with enhanced
conversion of the prehormone proinsulin to insulin as the most
likely explanation for protection against type 2 diabetes.
Better understanding of the genetic and pathological mechanism
behind diabetes can open up new ways of preventing or treating type