Dog Genome Project
Genetic malfunction can lead to serious trouble
Genes are the blueprints for life. When a gene doesn't work properly or becomes damaged, serious
problems can result. Dogs and people both suffer from a host of genetic diseases. Like coat color or
body type, genetic diseases are inherited traits. When dogs are inbred (that is, bred to close
relatives), rare genetic defects, from eye disease to joint problems, are more likely to appear in the
puppies.
Genetic testing and pedigree study can help scientists identify problem genes and individuals who
carry defective copies of them. By not breeding dogs that carry faulty genes, fewer puppies are born
with defects.
New research in gene therapy also makes it possible to try replacing defective genes with healthy
copies. Of four successful attempts, three have been in dogs. One case involves a puppy blinded after
an inherited genetic disease destroyed his retinas. Within days after his eyes were injected with
healthy genes, he could see!
Genetics in action: which of these hips has a genetic disease?
Hip dysplasia (dis PLAY zhuh) is a common genetic problem with
purebred dogs. It occurs when the hip socket is too shallow to fit the ball joint of the
thigh bone. This causes pain when the dog moves, and often worsens with age as the
cartilage around the joint breaks down.
One of these illustrations shows a dog's healthy hip socket. The
other shows a dog with hip dysplasia. Can you see the differences? (Move your mouse pointer over the
pictures to see a closer illustration.)
