Decoded Dog DNA May Aid Epilepsy Research

Special to EpilepsyUSA
Posted: February 15, 2006

The results of a two-year-long scientific study gave the epilepsy community one more reason to dub canines "man's best friend." Scientists recently announced they had successfully mapped a dog's entire genetic makeup, a major accomplishment in the sense it has already begun providing some insight on genetic diseases in humans -- including epilepsy.

According to Eric Lander, Ph.D., director of the Broad Institute of Harvard and the Massachusetts Institute of Technology, "The genetic structure of dog breeds is so much clearer than in the human population that it will make genetic analysis much simpler."

Certain breeds of dogs are at higher risks for developing specific ailments. In the case of epilepsy, springer spaniels are most at risk. By studying the genetic makeup of individual dog breeds that contain the same disease -- for example, a group of springer spaniels with epilepsy -- scientists can hone in on the genes responsible. Because the blocks are so large, researchers can narrow locations of potential "disease genes" down to only a few possibilities.

Although the recently decoded DNA came from a boxer breed, the team of 250 scientists who performed this study says that won't really matter. According to their research, at the DNA level, two randomly chosen dogs differ only about as much as two randomly chosen people.

The researchers also estimated dogs have 19,300 genes, almost all of them canine versions of genes found in human beings. Previous studies indicated people have approximately 3,000 more genes, but Lander said dog analysis "is leading us to question whether those are in fact real human genes."

The dog joins the human being, the chimpanzee, the mouse and the rat on the list of mammals whose DNA has been read and transcribed. A much less detailed, less complete version of the canine's genetic makeup was published in 2003. The genomes of the fruit fly, a microscopic worm, yeast and several bacteria have also been decoded.