Marlborough Express - Weekend Express
How genetic testing can help fight diabetes
Jodi Rangitaawa changed her diabetes medication about a year ago after a genetic test taken 20 years before resurfaced, showing she had a rare form of diabetes.
Monogenic diabetes is a rare diabetes subtype 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 because of 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-greatgrandmother 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 that 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.”