By Sharon Gray
Researchers at the Faculty of Medicine are major collaborators
in the discovery of a novel gene relating to peripheral neuropathy.
A study published in the April online edition of the American
Journal of Human Genetics reports the discovery of the
gene linked to hereditary sensory and autonomic neuropathy
type II (HSAN II), a condition which causes loss of nerve
sensation in the hands and feet.
Drs. William Pryse-Phillips, Banfield Younghusband and Roger
Green from Memorial University and Dr. Bernard Brais of the
Centre de Recherche du Centre Hospitalier de l’Université
de Montréal identified several families with this rare
condition in Eastern Canada. Researchers at Xenon Genetics
Inc., a privately-owned drug discovery and development company
based in Vancouver cloned and validated the gene – called
HSN2 – underlying the disease in these families.
“The most important part of work is that we are finally
in a position to help families with this disease,” said
Dr. Ban Younghusband, chair of the Discipline of Genetics.
“HSAN II has an early onset and can lead to severe disability.
These findings will lead to our ability to offer DNA-based
diagnostic testing and genetic counselling to those family
members of who are at risk of developing the disease or of
having children with the condition.”
Identification of the molecular basis of HSAN II is an important
step in the diagnosis and future management of this and other
peripheral neuropathies. This gene may play a role in the
development or maintenance of peripheral sensory neurons or
their supporting cells. It is also possible that a drug based
on the action of HSN2 could be used to prevent or treat features
of peripheral neuropathy, including that resulting from diabetes.
Neurologist Dr. William Pryse-Phillips began
working with patients with hereditary neuropathy in 1972,
when he first came to Newfoundland. Using information gathered
by neurologist Dr. Max House, he began to gather further information
on families, mainly in the Notre Dame Bay area, with the disease.
Passing information over to colleagues Drs. Younghusband and
Green and well as Dr. Sharon Buehler, now honorary research
professor, Dr. Pryse-Phillips’ role was to make a final
diagnosis of the type of hereditary neuropathy the patient
had, as well as to treat the patient. Treatment involves counselling
on the need to constantly inspect and protect feet, treating
pain, and promptly treating complications such as cuts.
Dr. Pryse-Phillips, recently retired, said he was delighted
with the identification of the HSAN II gene and credited the
work of all those involved for its “obsessive precision.”
He said his ability to be clinically certain of the type of
hereditary neuropathy each patient had was instrumental in
Xenon’s skilful detection of the gene.
In November 2000, Xenon and Memorial University signed an
agreement to collaborate on three genetic diseases that are
prevalent in Newfoundland and Labrador. The agreement with
Memorial was negotiated through the university’s commercialization
organization, the Genesis Group. “This agreement, which
involved Xenon collaborating with university researchers in
St. John’s and Montreal, was a blueprint for how things
should be done in Canada” said David King, president
of the Genesis Group. “This collaboration was possible
because Memorial had access to the unique founder population
in this province and because the Faculty of Medicine had the
foresight in 1999 to set up a dedicated Discipline of Genetics.
But this is just the beginning, genetic research carried out
in Canada and at Memorial will bring great benefit to society
over the next decade.”