Research highlights
There are many researchers at the University of Otago that work in partnership with Māori and Pacific communities to conduct research on the genetics of a number of health diseases and issues.
Guilford.P 'Stomach Cancer Project'
Gastric cancer is the leading cause of cancer deaths worldwide and 10% of cases show familial clustering. This is when a disease occurs in a family more frequently than would be expected in random distribution, however, some clusters may be due to chance. For over 10 years, Professor Parry Guilford from the University of Otago worked with members of an extended Māori whānau (family) who were found to have unusually high rates of gastric cancer (Guilford, 1998).
A mutation in the E-cadherin gene was found to be responsible for this particular gastric cancer in 1997. This mutation was found in family members who were highly susceptible to developing gastric cancer. The gene plays a vital role in cell adhesion and prevents cell invasion, however, the gene is switched off in those whānau members who are affected by the mutation.
This familial gastric cancer was predominantly found in one Māori family where over 30 years, 25 family members died due to the disease (Guilford, 1997).
Through this research, Guilford has worked closely with the families affected and through this close collaboration, Guilford and his team were able to track the development of the cancer and develop a blood test for risk factors. Organisations such as the Kimihauora Clinic and the Northern Regional Genetic Services provides these services to the community. Guilford's engagement at this whānau level proved to be beneficial for understanding more about this specific gastric cancer but more importantly decreasing the risks of more family members developing the disease.
Cameron, V 'Heart Disease Project'
Genes are estimated to account for about half of the risk of developing heart disease in some individuals. Professor Vicky Cameron has focused her research on understanding the health disparities in cardiovascular disease (CVD) in the Maori community. A comparison was made between rural Maori where health services are limited with urban Maori and non-Maori in a city with easily accessible health care. The cohort study called 'Hauora Manawa' looked at the diagnosed and undiagnosed CVD, diabetes and risk factors. It is known that Maori have high rates of CVD mortality and morbidity. However, further understanding of the key risk factors underlying this ethnic disparity is still needed as most of the data come from self-reported diagnoses via national surveys.
Cameron et al., (2012) found that rural Maori who had limited access to health care were more exposed to risk factors for obesity, smoking, hypertension, dysplipidaemia, diabetes mellitus type 2 and hyperuricaemia compared to urban Maori and non-Maori. In addition to this, the study also made a point that the data collected from national health surveys really only accounts for urban Maori, which may significantly underestimate the CVD risk factors on rural Maori.
As a result of these findings, the Hauora Manawa Project has taken a Kaupapa Maori approach to improve the engagement of health care with Maori in rural (as well as urban) areas in New Zealand (Pitama et al., 2011). The Kaupapa Maori Methodology was applied by working with two tribal authorities to ensure clinical and research protocols were culturally appropriate. Pitama et al., (2011) also state that the increased participation in the project shows the acceptability and approval of this Kaupapa Maori methodology in engaging with Maori communities.
Merriman, T 'The Genetics of Gout in Aotearoa Project'
Gout is caused by elevated levels of a chemical called uric acid in the blood. In New Zealand gout affects 10-15% of Maori and Pacific Island men. When levels of uric acid get too high, crystals are formed in the joints, with very painful attacks of gout resulting from the immune system recognising the crystals as 'foreign', and inflaming the joint. The primary reason for people having high uric acid levels is an inherited tendency to excrete less uric acid through the kidneys. However, excess fructose in the diet, and foods rich in purine precursors of uric acid also raise uric acid levels. Uric acid levels in the blood can be reduced using the common drug allopurinol which targets production of uric acid in the blood.Uricosuric drugs such as probenecid and benzbromarone can be more effective as they increase removal of uric acid through the kidneys, targeting the primary reason for gout in most people.
Associate Professor Tony Merriman and his lab have been working in partnership with Māori and Pacific to establish the 'Genetics of Gout in Aotearoa' project.
Tony's lab have taken a genetic approach to the understanding of the biological causes of gout. They are comparing the frequency of genetic variants that we think cause gout between people with and without gout. This is being done mainly in Auckland and in collaboration with Ngati Porou Hauora.
Our research results
Key results so far have shown that a specific genetic variant within a gene called SLC2A9 approximately doubles your risk of gout if you are of European ancestry. However, if you are of Maori or Pacific Island ancestry, this variant increases your chance of gout by more than five times. Interestingly, this gene is targeted by the drug benzbromarone, which was not easily available to doctors in New Zealand. These research results have helped the New Zealand Rheumatology Association and the Middlemore Maaori Gout Action Group work with PHARMAC to ensure benzbromarone is now more widely available. Further results, on the ABCG2 gene, show that the inherited component of gout differs between populations, even within people of Polynesian ancestry. As a genetic variation in ABCG2 causes gout in Pacific and European people, but not Maori.