For centuries, the fierce independence
of the Basque people kept them largely isolated, linguistically
and genetically, from the rest of Europe. So while they
may be a thorn in the side of the Spanish government,
they're a boon to genetic research — finding an isolated
community is like hitting the jackpot in this field. Studying
a group of mainly Basque families with a predisposition
to Parkinson's, a team of European and American researchers
has uncovered a genetic mutation linked to the disease.
The research, published in the November 18 edition of
Neuron, will ultimately "help in the development
of targeted interventions that could actually alter the
course of this disabling disease," according to Dr Elias
Zerhouni, director of the US National Institute of Health
(NIH).
The culprit gene PARK8 was first
discovered in 2002, but its location remained unknown.
The gene's position was finally pinpointed on chromosome
12 when researchers studied samples obtained from members
of one English family and four Basque families with
a history of Parkinson's.
The cluster of Basque families
"helped us to narrow the genetic region [of chromosome
12] we were interested in," said project coordinator
Dr Andrew Singleton of the NIH Institute on Aging.
A
TALE OF TWO MUTATIONS
Two mutations were identified in the gene. One was linked
to Parkinson's in the Basque families and the other
was associated with the disease in the English family.
However, in both cases, chromosomes from healthy controls
or family members without Parkinson's did not contain
the mutation.
Similar mutations have since been
found in families around the world, and in 8% of 137
apparently unrelated Basques. This has made Dr Jordi
Perez-Tur, leader of the Spanish research team, confident
that "the gene we found might turn out to be one of
the major players in familial Parkinson's disease."
PARK8 codes for the manufacture
of a protein dubbed dardarin from the Basque word dardara,
meaning tremor. Dardarin's function is a mystery, however,
the researchers wrote that it is "particularly tempting
to hypothesize a role for dardarin in the phosphorylation
of proteins central to [Parkinson's disease]." Deciphering
this protein's true function will be the next step.
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