• At-home genetic testing

DNA Home Test Kits: A Genetic Counselor’s Perspective

By |2019-01-04T14:57:06+00:00December 10th, 2018|

The rise in popular at-home DNA tests such as 23andMe and Ancestry.com has skyrocketed. In the next few years, demand is expected to more than quadruple. Individuals can buy genetic testing kits from local retailers, send away samples of saliva, discover their ancestry, and learn their predisposition to many diseases and health conditions. They get it all for around $200.

Direct to Consumer Testing Limitations

mouth swab for genetic testWhat consumers may not realize is these “health reports” are actually fairly limited in their clinical clarity. The Food and Drug Administration regulates all clinical genetic testing in the United States, but this regulation is specific to clinical testing with a direct diagnostic application. This can leave confident DTC buyers with incomplete analyses.

For example, the DTC analysis of the most common genes associated with inherited breast cancers (BRCA1 and BRCA2, which are sometimes called BRACA) only covers the three most common genetic variants known to cause disease in the Ashkenazi Jewish community. These are three variants out of around 6,000 known to be disease causing in BRCA1 and BRCA2. This is not well advertised by the laboratories selling the tests.

There are also many third-party companies offering to analyze the “raw data” from ancestry-testing laboratories. They claim this raw data also can reveal serious health conditions, including inherited cancer syndromes. The problem is that the testing techniques and data analyses are not always accurate. Individuals can receive erroneous results. This can be a terrifying experience.

Accurate Genetic Testing

We know that the majority of breast, ovarian and colon cancers (about 85%) are random events. This means that about 10-15% of cancers are caused by a gene (technically a mutation in a gene) that can be passed down the family. This can have a dramatic effect. For example, some genetic variants raise the risk of breast cancer from 12.5% (average for a woman) to 75-80%.

We estimate that approximately one in 250 people carry one of these genetic variations, and that about 90% of people carrying disease-causing variants are unaware of it.

Just think of those numbers next time you are at a ballgame, and you look around the crowd.

The sad thing is that for those who carry the genetic variants and are at higher risk, these cancers can be, for the most part, prevented or caught at very early stages.

No Referral Needed

There are a lot of myths and false information buzzing around about genetics. These include the cost, referrals and privacy. Most clinical testing costs less than $250 to the patient. Patients do not need referrals to see most genetic counselors. Genetic testing is protected by GINA, the Genetic Information Nondiscrimination Act (2008). This means patients cannot be discriminated against by health insurance companies on the basis of a genetic test.

Informed Decisions

As genetic counselors, we seek to help patients understand their risk factors for hereditary cancers so they may make informed healthcare decisions. In a typical consult, we will:

  • Review up to three generations of the patient’s family history
  • Discuss the patient’s and his or her children’s cancer risk factors
  • Provide information on cost of testing/insurance coverage
  • Test comprehensive panels of genes associated with inherited cancer syndromes
  • Follow up with the patient and his or her physician about the results

By examining three generations of family history, patients gain an understanding of their likelihood of breast, colon, ovarian, prostate and uterine cancer. We’re interested in helping people who may have cancer caused by a change in a gene in an inherited syndrome, but we also counsel and test people who are concerned about their future health. It is important to note if an individual has no information about their family history whatsoever, this does not exclude them from genetic testing.

Prevention and Control

With each patient, we explain cancer genetics and what we’re looking to find. If we have a positive result, we discuss their and their family members’ health implications. These are important considerations for the patient to make informed decisions about whether to pursue testing.

Some patients will opt out of testing. If a patient doesn’t want to get tested, I’m completely supportive of that. We want to provide good service to our patients. Call 913.574.1050 to schedule your genetic counseling appointment.

About the Author:

Alisdair Philp, PhD, MS, CGC
Dr. Philp, a board-certified genetic counselor with The University of Kansas Cancer Center, provides genetic counseling services at North Kansas City Hospital. He earned doctoral degree in biological sciences and genetics from Imperial College of Science, Technology and Medicine at the University of London. He also was the Henry M. Jackson Foundation Research Fellow at the Uniformed Services University of Health Sciences, Bethesda, Maryland. He spent four years as a Howard Hughes research scientist at the University of Iowa and four years as a faculty member at Des Moines University, conducting research and teaching genetics to medical students. He completed his master’s degree genetic counseling at Northwestern University before moving to the Kansas City area.

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