DNA Research and Dog Breeding
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By Amy Fernandez
Among other things, breakthroughs in genetic research have revolutionized dog breeding. It’s removed the guesswork from many aspects of the job, thus allowing us to focus on our real task of creating a living work of art. Since the first canine disease mutation was identified back in 1989, researchers have documented hundreds of mutated alleles that can signal a hereditary predisposition to various health issues.
The pace of these innovations and technological advances kicked into overdrive following the completion of the $30 million canine genome map in 2005. It’s led to the identification of DNA markers for countless traits and an avalanche of tests to facilitate the identification and management of genetic disorders. The rapid, multifaceted evolution of this field makes it difficult to pin down the scope of screening procedures now available. Currently, 43 laboratories worldwide offer almost a hundred different tests for conditions affecting approximately 120 breeds.
Because predictive genetic testing has been such a game changer, one crucial factor of this situation is frequently overlooked. So far, this fledgling industry has been largely unregulated. Along with the steady flow of innovations there have been growing concerns about the potential for misapplication and misuse of this technology.
In reality, the speed of technical transformation overtaking biomedical research has made it nearly impossible to effectively regulate any aspect of this brave new world. Arguably, the lack of restriction has encouraged scientific insight and entrepreneurial genius. It’s also led to a mess of inconsistent testing procedures with variable accuracy and no definitive guidelines to determine which mutated alleles genuinely merit consideration as predictive indicators.
Although many genetic hallmarks have been linked to various conditions, they are not equally significant predictors of disease. For instance, affected individuals don’t invariably develop any or all aspects of an associated condition. Equally often, a genetic predisposition represents just one of several contributing factors that ultimately tip the balance into disease. This is one of those gray areas where science and ethics collide.
However, most current worries stem from the growing number of agencies providing an expanding repertoire of testing services to analyze blood and tissue samples. Discrepancies in their equipment and methodology can and does lead to conflicting results and scientific confusion. And this need for industry standardization is looming larger as mainstream medicine increasingly relies on DNA markers to diagnose disease and tailor treatments based on personal genetic profiles. In that respect, the big mess could become a lot messier.
But we may be making some headway to untangle this formidable ball of confusion. Recently The National Institute of Standards and Technology announced that it now has a stake in the game. Since 1901, this non-regulatory federal agency has been developing and defining quality control benchmarks euphemistically known as SRMs (Standard Reference Materials). A mind-boggling array of public and private industries and agencies utilize NIST SRMs as a baseline of standardization and quality control. Genomic researchers can now access the newest addition to the extensive NIST database of quality control benchmarks, their brand new database of Short Tandem Repeat (STR) DNA markers to gauge the consistency and accuracy of gene sequencing and testing.
Developments in canine genomics frequently parallel innovations in human genetic research and NIST has published a partial list of canine STR markers documented in scientific literature to date. The International Society of Animal Genetics has also developed a set of validated canine genetic markers that labs can use for comparison and standardization purposes. However, the value of the ISAG Profile is dependant on its reciprocal use by testing labs, which is voluntary rather than mandatory.
Obviously, cohesive universal standards and practices are the key to mainstream utilization of this technology. But even without it, the biomedical industry is churning out a growing mountain of genetic data and consumer dollars are the rocket fuel propelling this business to new heights.
Today, DNA heritage testing ranks as the largest, and possibly most notorious, sector of the genetic screening industry. Marketed directly to consumers, the fallibility of these tests began making news back in 2009 when the FDA provided a reality check aimed at curbing overblown marketing claims and customer expectations about these tests. Federal intervention has encouraged tighter standards and more realistic product descriptions, and certainly didn’t deter the demand for home test kits that run about $100-$250.
Canine versions first hit the shelves around 2007 and were originally marketed to consumers as a way to satisfy their curiosity about their dog’s ancestry. Priced comparably to the human versions, they often yielded conflicting, sometimes laughable results. Most of the problems stemmed from the typical industry issues. Each lab compiled its own database of genetic markers and used its own methods to assess samples and interpret results. Those additional variables compounded the already substantial challenges of unraveling randomly bred, undocumented canine family trees.
Despite their hefty price tag and questionable accuracy, demand for this product has remained consistently strong. Over 12 companies now offer canine heritage testing from $100-$200, making a multimillion dollar business out of this most popular canine genetic test.
Perhaps it’s controversial and ethically questionable but marketing has become an accepted feature of American health care. It also underlies the aggressive efforts to expand the market for this particular expensive novelty product which is now being promoted as a predictive health screening tool and more. Armed with this information, owners can supposedly tailor their dog’s environment, training, and veterinary care.
That claim is based on research which acknowledges a link between certain mitochondrial mutations and markers for genetic disorders. But that’s the extent of scientific evidence to support these promotional efforts. The debatable accuracy or diagnostic value of these tests really doesn’t matter because the average consumer views DNA testing as the cutting edge of scientific precision. Americans spent 48 billion dollars on their pets last year. That rather staggering figure certainly suggests that owners want the best for their pets and they are more than willing to pay for it. And that definitely includes canine heritage tests to screen randomly bred dogs for breed specific health disorders, medication sensitivities, and predict a pup’s adult size, activity level, and behavioral propensities.
It’s true that these tests have improved and are now promoted as being 85-90 percent accurate. Even so, utilizing this information to proactively manage veterinary care amounts to a purely speculative exercise simply because it is based on unproven assumptions about the heritage and genetic makeup of undocumented ancestors with inferred medical and behavioral predispositions. It also seems rather counterintuitive when you consider that these genetically jumbled designer dogs have been consistently promoted as the healthy, temperamentally balanced alternative to “genetically defective, mentally unstable” purebreds. Of course, consumers can always resort to that old school, low-tech method to predict a dog’s physical appearance, health, and behavior parameters – choose a documented purebred.
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