Genetic form of Parkinson’s common in Pacific

A genetic form of early-onset Parkinson’s disease that can affect children as young as 11 has previously been considered rare, but a new study shows it is relatively common in western Pacific nations.

The research found that about one in 1,300 western Pacific people carry a variant of the PINK1 gene that increases the risk of early Parkinson’s disease; a rate which far exceeds the usual threshold for a ‘rare’ disease of fewer than one in 2,200. See Journal of Parkinson’s Disease.

The research was prompted by a 2021 study that identified five individuals of Sāmoan and Tongan descent in New Zealand with PINK1-mutated Parkinson’s, says Dr Victor Dieriks, from the Centre for Brain Research at Waipapa Taumata Rau, University of Auckland, who led the new study.

All five carried the same variant, p.Leu347Pro, which had previously been reported only in Malaysia, Guam, and the Philippines.

This suggested a historical link, likely tracing back to early Southeast Asian migration through Polynesia.

“This finding in 2021 hinted that certain populations might be disproportionately affected, but previous research had overlooked these communities,” Dieriks says.

This new study shows this to be the case.

He would like to see further research in the western Pacific, along with genetic testing.

“Parkinson’s disease is often treated as a single disorder, but in reality, it's a collection of syndromes with diverse causes – genetic, environmental, or a combination of both,” Dieriks says.

In future, genetic testing for Parkinson’s could improve treatment for people with various forms of the disease.

PINK1 Parkinson’s typically starts earlier than general Parkinson’s, often in a person’s mid-30s and sometimes in children.

While general Parkinson’s is more common in men, the PINK1 genetic form appears earlier in women.

Levodopa is the gold standard treatment for Parkinson’s, and it works well for many PINK1 cases, but it only addresses symptoms and doesn't target the root cause, Dieriks says.

“Developing treatments specifically for PINK1 Parkinson’s could help individuals maintain independence longer, reduce the strain on families, and lessen the overall burden on healthcare systems.”

Dieriks would like to see genetic testing for all forms of Parkinson’s, saying it could be a game-changer.

Since PINK1 Parkinson’s often presents differently and earlier than typical Parkinson’s, it can be misdiagnosed or missed entirely.

Early genetic testing would not only lead to faster, more accurate diagnoses but also help families understand the inheritance patterns of the disease.

For communities where PINK1 mutations are more common, widespread genetic testing could offer critical insights into who is at risk and how best to manage or prevent the disease.

To truly understand PINK1 Parkinson’s, we need to engage with the communities most affected, Dieriks says.

“This means not just focusing on the genetic or molecular level but also understanding the lived experiences of people with the disease.

“What symptoms do they notice first? How does the disease affect their daily lives and families? Is there a stigma around Parkinson’s in these communities, and how does that impact their willingness to seek treatment?”

In addition to community-level research, more genetic studies focused on Pacific populations are urgently needed.

“While many cases have been identified in New Zealand, there’s been little to no research conducted in Sāmoa, Tonga, or other Pacific nations where the disease may be even more prevalent,” Dieriks says.

“The lack of ethnic diversity in Parkinson’s research is a persistent problem that won’t solve itself. We need intentional efforts to direct more resources and funding toward under-represented populations, especially outside of Europe and industrialised nations.

“Our study found that many PINK1 cases in Polynesian people were identified in New Zealand, but no research has yet been conducted in their countries of origin.”