THE residents of Norfolk Island, most of whom are descended from the sailors
who seized the British ship Bounty in 1789 and set up home in the South Pacific,
may soon repay some of the debt to society left by their mutinous ancestors. The
DNA of this uniquely isolated community may help researchers find the genes
which predispose people to cardiovascular disease.
A team of Australian geneticists is currently collecting DNA samples from the
islanders. For the past three months, Lyn Griffiths, director of the genomics
research centre at Griffith University in Queensland, has been on Norfolk with
two fellow researchers collecting DNA samples from as many of the 900 permanent
adult residents as possible. They have collected samples from 550 so far.
Between 600 and 700 of these people can trace their roots back to the British
mutineers who cast their captain William Bligh adrift in a small boat. They and
some Tahitian women settled on Pitcairn Island, but in 1856 their descendants
moved to Norfolk Island, 1500 kilometres east of Australia.
Advertisement
Griffiths chose to study the Norfolk Islanders because of their isolation,
genetic history and strong family ties. 鈥淗ere we have people of mixed
Tahitian-English origins,鈥� she explains. 鈥淧eople of Polynesian descent tend to
run a high level of cardiovascular disease, while their English background, I
felt, might contribute to additional cardiovascular disease. Their eating habits
are decidedly old English with high cholesterol in the diet. Many are keen on
fried foods and additional cream.鈥�
An added benefit of studying the Norfolk islanders, Griffiths says, is that
there are fewer environmental differences that could blur genetic studies. They
have all eaten a largely similar diet, drunk from the same water supply and been
exposed to similar levels of pollution. 鈥淢any of the diseases I am interested
in,鈥� she says, 鈥渁re a combination of several genes and environmental triggers.
Here, the population is so isolated you can reduce environmental differences so
you concentrate on genetic factors.鈥�
Griffiths hopes to use the genetic information she acquires to pinpoint genes
which predispose people to high blood pressure or to migraines. 鈥淲e have been
working on these conditions for some time,鈥� she says, adding that she has a very
strong candidate gene for high blood pressure. 鈥淲e need more evidence which this
will hopefully provide.鈥�
The islanders will get something out of the research too. At present they
have only a small hospital, limited access to doctors and poor health records.
Griffiths鈥檚 team will provide the local administration with crucial information
for planning a health strategy for the island. The researchers have also signed
an intellectual property agreement with the islanders, who will share in any
profits from the research.
