In a world-first genome-wide association study in an Australian Aboriginal population, researchers from Perth's Telethon Kids Institute have shown that genetic variations that influence body mass index (BMI) and diabetes are similar to those in non-Aboriginal populations.
The results have just been published online in the international journal PLOS ONE and provide an important step towards translating the benefits of health-based genomic research to Australian Aboriginal populations.
The research team worked closely with a Western Desert community and their Aboriginal Health Service to look at genetic associations with BMI and diabetes.
Researchers collected saliva samples from 402 individuals in the community including 89 with Type 2 diabetes. DNA was extracted from the saliva and placed on a chip which allowed more than one million genetic markers to be typed for each individual. Genetic statistical methods were then used to compare these genetic markers across all 402 individuals to identify the genes associated with BMI or Type 2 diabetes.
Study leader, UWA Professor Jenefer Blackwell, said the results showed the top association was between BMI and NTRK2, a gene that codes for a receptor for brain derived neurotrophic factor (BDNF) that regulates energy balance in a pathway downstream of the melanocortin-4 receptor MC4R.
"Our finding of the association between BMI and NTRK2 is novel but genetic variants at both BDNF and MC4R have been strongly associated with BMI in studies in other populations," said Professor Blackwell.
"Our results show that genes influencing BMI in this Aboriginal population belong to the same biochemical pathways as have been observed in large-scale international studies of BMI.
"This means that research being undertaken to target therapeutic advances at this pathway will be relevant to this Australian Aboriginal population, while NTRK2 might provide a novel therapeutic target within the pathway for Aboriginal people."
Professor Blackwell said while the results are exciting, it is early days and more research is needed.
"This is a small study in just one population and the results will need to be corroborated in other studies of Australian Aboriginal populations," Professor Blackwell said. "We hope the publication of our results will encourage other researchers and communities to take up the challenge."
Mr Richard Whittington JP AM, who is CEO of the Aboriginal Health Service, says the study was something different for the community to be part of.
"We all learned lots along the way," Mr Whittington said, "with a week-long Feedback to Community project helping the community, and especially the kids, to understand more about Type 2 Diabetes and the benefits of staying fit. The kids had fun producing an animation - 'The Goanna and the Journey of the Gene' - that was premiered at a community festivity and uploaded to YouTube with the permission of the local Elders."
Mr Glenn Pearson, Head of Aboriginal research at the Telethon Kids Institute said the study had been a long time in the making and it was exciting to see it come to fruition with some important genetic findings.
"Of key importance was the assurance that the local community was fully engaged in the process," Mr Pearson said, "and that governance was established to ensure that no harm would be associated with taking the bold move of being the first community to engage in this kind of study.
"We hope this has paved the way for the translation of modern genetic approaches to health-based research in our Indigenous communities."
Type 2 Diabetes and associated pathologies are a major health problem in Indigenous Australians, and high BMI is a significant risk factor for T2D. A 2002 study published in the journal Diabetes Research and Clinical Practice showed the prevalence of diabetes in the Aboriginal population to be 142 cases/1000 persons among men, and 152 cases/1000 persons among women.
The YouTube video on "The Story of the Goanna and the Gene" is available online in both Martu and English languages versions.
--ends--