How genetic testing can help New Zealanders with a rare form of diabetes
Finding out she had a rare diabetes subtype helped Jodi Rangitaawa improve her health, give her whānau a better understanding of their diabetes, and start a kōrero with their children and mokopuna. Jodi Rangitaawa, a Māori woman, changed her diabetes medication after a genetic test taken 20 years ago revealed she had monogenic diabetes, a group of rare diabetes subtypes caused by changes in a single gene. Monogenic diabetes is a rare form of diabetes that affects about 1% of people in New Zealand. However, due to a lack of testing, only 300 people in the country have been diagnosed with this form, far below the expected 2800. Rinki Murphy, a professor of medicine at Auckland University, said that there is a gap in evidence for how best to identify people of Māorori and Pacific ancestry who might have monogenic di. She suggested that targeted testing would be the best place to increase genetic testing and suggested increasing funding allocated for such testing.
公開済み : 2年前 沿って Adam Blackwell の Health
Jodi Rangitaawa changed her diabetes medication about a year ago after a genetic test taken 20 years prior resurfaced, showing she had monogenic diabetes.
Monogenic diabetes is a group of rare diabetes subtypes caused by changes in a single gene. About 1% of people in New Zealand with diabetes would be expected to have it. However, the actual number is not known due to a lack of testing.
About 280,000 people have been diagnosed with diabetes in Aotearoa, but only 300 people have been diagnosed with monogenic diabetes, well below the 2800 expected, according to Rinki Murphy, a professor of medicine at Auckland University.
Rangitaawa said after finding the tests results, she had changed from using insulin to oral medication.
This led her to lose about 12kgs, and her HbA1c test, which monitors blood glucose, was the lowest it had been for as far back as she could remember.
Diabetes goes back many generations in Rangitaawa’s family. Her great-great-grandmother died from diabetes mellitus, and many family members have had, and been affected by the complications of, the disease.
Genetic testing for diabetes is not widely available in New Zealand, but Rangitaawa had tests done about 20 years ago when a diabetologist was curious about her family history and asked to send her blood overseas to be tested.
When the result came back, Rangitaawa was told she had a gene which meant there was a 50% chance her kids would have diabetes, and she needed to monitor it, but that was about the end of it. She stayed on insulin and was treated as a type 2 diabetic for the next 20 years.
Then, a couple of years ago, a doctor was interested in her mother's diabetes and went looking for the tests Rangitaawa and her siblings had done in 2004.
Those results were found and led to the change of medication for Rangitaawa. But locating the results didn’t just help her health, it also opened up the conversation with her whānau.
Knowing more about it helped her whānau have a better understanding of their diabetes, find the best treatment options, and start a kōrero with their children and mokopuna.
“We have only just started processing the enormity of how this could affect all the different threads of our family,” Rangitaawa said.
Rangitaawa has a background in health work, and said she had lots of experience with whānau who would benefit greatly from knowing more about diabetes.
“I guess for Māori you don’t usually talk about this stuff until it is happening, and then it is too late. And diabetes is such a silent disease in the big scheme of things, especially the type we are talking about.
“Peoples’ bodies can compensate, they are an amazing machine, they can do a whole lot of stuff, and it is not until all the complications are showing that you actually find out you’ve got diabetes, because that is when you finally go to the doctor.”
Rinki Murphy, an endocrinologist, said there was a gap in evidence for how best to identify people of Māori and Pacific ancestry who might have monogenic diabetes, in whom diabetes genetic research is lacking.
“Given the high prevalence of obesity in Pacific peoples and in Māori, those who develop diabetes are more frequently classified as having type 2 diabetes, and so NZ data shows that the referral for genetic testing is lower and the yield for monogenic diabetes is lower than in Europeans, particularly in Pacific peoples.
“We don’t have the research to show what other biomarkers may be more informative for this population.”
Murphy said genetic testing in New Zealand is currently implemented “ad hoc” and there was lack of a national strategy and funding allocated to systematically identifying and managing monogenic diabetes.
It would be too expensive to provide a genetic test for everyone with diabetes, current costs are about $1200 per test, so targeted testing would be the best option.
She said the most productive place to increase genetic testing would be whānau of those who have already been diagnosed with monogenic diabetes, and those who were diagnosed with diabetes in the first year of life.
Genetic testing would also be appropriate for people with atypical clinical features for common type 1 or type 2 diabetes, such as those who still have residual insulin production despite being diagnosed with type 1 diabetes or active slim people who have been diagnosed with type 2 diabetes or gestational diabetes.
Penny Rich was offered genetic testing for free in 2012 as part of a research project, and said knowing the exact diabetic gene mutation she had was “life-changing”.
“For over a decade, I have been given the best medications for my genetic subtype, and have managed excellent diabetic control.”
Rich would like to see more funding for genetic testing for diabetes so others could have the same help she had.
“I think one of the key things with gene testing with diabetes is it’s incredibly effective, but it should be funded somehow, because it’s not something people really have money to go and pay for.”