Man's best friend recruited in the hunt for disease genes

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Man's best friend recruited in the hunt for disease genes

http://www.eurekalert.org/pub_releases/2008-10/esf-mbf101608.php

For centuries man has had a uniquely close relationship with dogs –

as a working animal, for security and, perhaps most importantly, for

companionship. Now, dogs are taking on a new role – they are helping

in the hunt for genetic mutations that lead to diseases in humans.

" Dogs get very similar diseases to humans, " said Kerstin Lindblad-Toh

of Uppsala University in Sweden and the Broad Institute of MIT and

Harvard, Cambridge, Massachusetts. " If you ask a dog owner what sort

of conditions their pets get, they will say cancer, allergies, eye

diseases. "

Lindblad-Toh was speaking at the European Science Foundation's 3rd

Functional Genomics Conference, held in Innsbruck, Austria, on 1-4

October. Functional genomics describes the way in which genes and

their products, proteins, interact together in complex networks in

living cells. If these interactions are abnormal, diseases can

result. The Innsbruck meeting brought together more than 450

scientists from across Europe to discuss recent advances in the role

of functional genomics in disease.

Many canine diseases could share the same genetic basis in humans and

dogs, Lindblad-Toh told the conference, and because dogs have been

bred into clear isolated populations – the different breeds – it is

often easier to detect a genetic flaw that leads to a disease than it

is in humans. Once the rogue gene has been found in the dog, it could

make it easier look for mutations in the same gene in man.

" For example we have found genetic mutation that results in a

condition called day blindness that can affect dachshunds, " Lindblad-

Toh said. A similar condition can arise in humans, and analysis of

the mutated protein in the dog is providing new information about the

disease in man. The team is also looking at genes associated with

cancer of the blood vessels to which golden retrievers are prone.

A new European consortium has been set up called LUPA, where twenty

veterinary schools from 12 countries spread across Europe will work

together to collect 10,000 DNA samples from purebred dogs, comparing

healthy animals with those affected by similar diseases as human. The

analysis of the genome of affected dogs compared to healthy ones of

the same breed will lead to the identification of genes implied in

the mechanisms of these diseases. The four-year project aims

initially to pinpoint genetic markers for dog diseases and help to

reduce the high level of inherited disease in purebred dogs. The

identification of these genes implied in disease development will

help to understand the mechanisms and pathways of the pathology.

For example in Sweden, more than one-third of English Springer

Spaniels are diagnosed with mammary tumours, analogous to breast

cancers in humans. An increased risk for malignant mammary tumours

has been reported also in other breeds, including Cocker Spaniels,

German Shepherds and Boxers, suggesting that these breeds may carry

genetic risk factors for this type of cancer. If the genes implicated

in the disease can be singled out this could provide a new

opportunity to improve prevention, diagnosis and treatment of human

breast cancer.

" We want to find a lot of risk factors and bring them back to human

patients over the next few years, " Lindblad-Toh said.