Polynesian genes hold scientific secrets

Polynesians are known for being big. Samoans, Tongans, Cook Islanders and Rotumans have the trait to become big after a certain age.

In a recent release by the World Health Organisation, Polynesian nations have recorded data that show them to be the heaviest nation per capita.

This trait is now the centre of a study giving researchers clues to the genetic basis of high cholesterol in all people, according to new research led by the University of Pittsburgh (Pitt) School of Health and several other partners including the University of Otago and a Samoan health research community.

Researchers believe that if the study would have been focused on any other group of people, then this important discovery would have been missed.

The discovery is of a genetic variant which the researchers described as “relatively common” among people with Polynesian ancestry but rare in most other populations.

Polynesians might hold the key to locking the secrets behind the cholesterol gene. Pciture Cook Islands Tourism
Polynesians might hold the key to unlocking the secrets behind the cholesterol gene. Picture: Cook Islands Tourism

Lead author and Assistant Professor of human genetics and biostatistics at Pitt Public Health, Dr. Jenna Carlson, said if they had focused on European ancestry they would have missed the finding.

“If we had only been looking in populations with European ancestry, we might have missed this finding entirely,” Dr. Carlson said.

“It was through the generosity of thousands of Polynesian people that we were able to find this variant, which is a smoking gun that will spark new research into the biology underlying cholesterol.”

High cholesterol is a major cause of disease burden in countries of all income levels, is a risk factor for heart disease and stroke, and is estimated to cause 2.6 million deaths annually worldwide, according to the World Health Organisation.

Dr. Carlson and her team built their study to explore a signal that popped up in a large genome-wide survey looking for genes associated with lipids, or fats, in the body. It suggested that a gene variant on chromosome 5 could be associated with cholesterol, stated the Pitt media release.

The team then set out to “fine map” the region using genetic data from 2,851 Samoan adults from the Obesity, Lifestyle, And Genetic Adaptations (OLAGA, which means “life” in Samoan) Study Group who had also provided health information, including lipid panels.

To double-check the finding, the team looked for the association in 3,276 other Polynesian people from Samoa, American Samoa and Aotearoa New Zealand, and the same connection between the variant and cholesterol was seen in them.

Polynesians are big people and they are proud of that. Picture Samoa Tourism
Polynesians are big people and they are proud of that. Picture: Samoa Tourism

The Pitt media release said using data from the western Polynesian Samoan participants, the team was able to fill in the missing information around the region they were interested in.

Is this the world’s best island destination?
Paris turns blind eye to French Polynesia’s independence referendum

Dr. Carlson and the researchers didn’t know a lot about the variant that was discovered as there was no information published on it in genome references.

“We don’t know a lot about this variant because it’s not seen in published genome references, which overrepresent European ancestry individuals – it’s virtually nonexistent in European ancestry populations, has very low frequency in South Asians and isn’t even particularly common in eastern Polynesian people, such as Māori living in Aotearoa New Zealand,” she said.

“But the way it’s linked to lipid panels in Samoan people tells us that this gene is important to cholesterol, something we didn’t know before.”

Leave a Comment

Your email address will not be published.

You may also like

Send this to a friend