ASSESSING YOUR GENE KNOWLEDGE

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The Macula Risk test by Arctic Medical Laboratories is a simple process, done with a cheek swab.
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Illumina’s Hi Seq X Ten genome sequencer can deliver a whole human genome analysis for just $1,000. 
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Adoption of genetic technology can help ECPs differentiate themselves in the marketplace. 

New genetic tests and information can help guide your medical decisions and better serve your patients—you just need to know where to look.

It’s been a decade since the completion of the human genome project and in those years our understanding of how genetics impacts disease and how we can use that knowledge for the benefit of our patients has grown at an exponential rate.

Ever since Angelina Jolie’s controversial and highly publicized decision regarding her BRAC1 genetic profile, this topic has been brought to the forefront of public discussion””and it’s not going away. The key difference is that her medical decisions were made on genetic potential in the absence of clinical disease, triggering a debate of what genetic testing actually can or cannot do. Currently, there are more than 3,000 different tests that can be used to examine the genetic traits of an individual.

Needless to say, all segments of our healthcare system, including optometry, are in a state of transformation. As ECPs, we are constantly inundated with new technology, advanced diagnostic and therapeutic options, as well as legislation that is changing the foundations of what and how we deliver care.

MYTH VS. REALITY
Along with the expansion of testing options, there are growing questions of how and even if genomics and genetic testing can or should be integrated into an optometric practice. With all the hype and misconceptions, it’s common to wonder about the current state of this science and how it can actually help grow one’s optometric practice. Do you fall into one of these categories of false impressions? Read below for a reality check.

Misconception: Genetic testing is only for rare diseases.

Reality: While it’s true that many of our most debilitating ocular diseases are thankfully  atypical, there are multiple research groups looking at the genetic contributions to conditions that ECPs deal with on a daily basis, namely age-related macular degeneration (AMD), glaucoma, and refractive error.

Misconception: Many believe that genetic testing is too expensive to be cost effective for routine use.

Reality: The truth is, the costs for conducting a karyotype or routine chromosome analysis are actually less than an MRI or a CT scan. Private insurance and Medicaid coverage of more customary genetic tests have noticeably improved and many of the clinically significant tests for eyecare are now covered. Costs of genetic testing have dropped dramatically in the last decade with the development of new genomic analysis technology. Ten years ago the cost for the first whole genome analysis was in excess of $100 million. In January, San Diego, CA-based Illumina Inc. announced its Hi Seq X Ten genome sequencer that is reported to be able to deliver a whole human genome analysis for just $1,000.

Misconception: Having a genetic analysis only provides a label and will not help in the final clinical treatment and management plan.

Reality: This is where much of the current debate arises. In November 2012, The American Academy of Ophthalmology Task Force on Genetic Testing released a statement saying: “Avoid routine genetic testing for genetically complex disorders like age-related macular degeneration…until specific treatment or surveillance strategies have been shown in one or more published clinical trials to be of benefit to individuals with specific disease-associated genotypes. In the meantime, confine the genotyping of such patients to research studies.” This author agrees that the current state of genetic testing is not at the level of specificity and sensitivity to use a genetic test to differentially diagnose dry from wet AMD. However, combining your skills of a clinical evaluation with the potential risk factors provided by genetic testing can dramatically alter the treatment and management plan for a patient.

TESTS TO KNOW
One company providing macular degeneration risk analysis is Macula Risk, a division of Grand Rapids, MI-based Artic Medical Laboratories. The test is reimbursed by managed care plans and all billing for the test is done directly from Arctic Medical Laboratories.

The process is simple and streamlined. All the sampling supplies are provided, including shipping labels and transport media. You give the patient’s demographics including diagnosis, extent of disease progression from drusen presentation, BMI, smoking status, and age. Arctic Medical Laboratories then conducts a detailed analysis looking specifically at 15 gene markers from 12 AMD associated genes.

This information is summarized in a report that calculates the patient’s genetic risk factors for progression to advanced macular degeneration. Further, the Vita Riskâ„¢ pharmacogenetic result (within the Macula Risk test), supports the genotype-directed selection of appropriate eye vitamin formulations. Specific eye vitamin formulation (i.e., AREDS, antioxidants, or zinc) shown to result in
the greatest reduction in the risk of progression to advanced AMD for the patient’s genotype is recommended.

So how does an ECP in the trenches figure out what tests are available, which ones have the evidence-based data to support their use, and where to send patients to have them done? The Centers for Disease Control has an established site where ECPs can keep up with the latest developments within genomic research and clinical applications. One dedicated page, in particular, looks at recommended tests based upon evidence-based standards (cdc.gov/genomics/gtesting/tier.htm). Though not eyecare specific, it has a vast amount of information on genomic medicine.

THE GENE POOL
In order to better serve our patients, ECPs need readily available information. Key to this is guidance on what test to give, when to test, how to test, and where to have testing done for our specific patient. A top resource is New Jersey-based GeneTests, a clinical, no-fee site with a directory of more than 600 international laboratories offering molecular genetic testing, biochemical genetic testing, and specialized cytogenetic testing for more than 3,000 inherited disorders. The site also features a clinic directory of more than 1,000 U.S. and international clinics providing diagnosis and genetic counseling services to patients and their families with known or suspected inherited disorders.

Genetic testing is here now; it is growing at an amazing rate and is predicted to become the new standard of care for many of the eye conditions we manage daily. Having the tools to understand these new technologies is critical to meeting the needs of our patients. Adoption of this technology allows us to differentiate ourselves in the marketplace, add value to our practice, and provide even better care to our patients.

Ken Eakland is a professor at Pacific University College of Optometry in Forest Grove, OR.

WHERE TO FIND IT:

ArticDx •866-964-5182 •macularisk.com

GeneTests •888-729-1204 •GeneTests.org

Illumina Inc. •858-202-4500 •illumina.com

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