DNA Testing: Considerations Before You Test


If you’ve seen a television commercial about DNA testing and thought about ordering a kit for yourself, you aren’t alone. DNA tests, once confined to paternity courts, forensics labs, and medical clinics, are now available for purchase at the drug store or online. The number of tests climbs by the year along with the uses.


With the growth of tests like those from Ancestry and 23andMe, questions naturally arise. These tests promise to connect people to unknown genetic relatives, reveal ethnic background, and possibly uncover latent health factors. Most of the time, no huge discoveries are made from an at-home test. But there is a lot to consider before diving in, as some sticky situations are arising for a minority of testers.


Many of the points to consider are tucked away in the terms of service you agree to when you order a kit. But how many of us read all the fine print or can read between the lines to fully comprehend a companies’ warnings? Here are some of them, converted into language we all can understand:


  • Some companies plan to sell your de-identified genetic data and health survey results for profit or will turn it over to researchers or pharma. Are you okay with this?
  • Some people discover family secrets as a result DNA testing, like a hidden adoption in the family or somebody not matching a parent as a biological child. How would you and family react to this type of surprise?
  • Some people have discovered that family lore or suspected ethnicity differs from what the DNA shows. How might you feel if a DNA result raises questions about the genealogical truths that have been passed down through your family?
  • The majority of DNA testing evaluates only a tiny fraction of a person’s entire genome (sometimes as little as 0.02% of it, in fact). Do you know what type of genetic technology is being used by the company you’re ordering a kit from, or how much of your DNA sequence is being taken into account?
  • DNA results in the medical setting undergo intense scrutiny and must meet rigorous standards of accuracy and usefulness. At-home tests don’t have to meet these same standards, and recurrent issues with at-home DNA results have come to light. Do you understand the extent of limitations for the test you are ordering?
  • Impact of DNA results on the ability get different types of insurance in the future is a common concern, and the legal protections and potential risks are moving targets. How will you know if the benefits will outweigh the risks for you?

Many people find tremendous value in the results they receive and say that DNA testing has filled in a piece of the puzzle that couldn’t have been filled any other way. The promised benefits outweigh the possible risks for many. Consider speaking with me or another genetic counselor as you explore your options and are making a decision. Genetic counselors are specially trained professionals who can help you think through and understand the terms of service you’re agreeing to when you hand over your DNA sample, whether to a consumer testing company or in the medical clinic. Whether the testing you consider has implications for health, family, or ancestry, there’s no better time to think ahead about the results to come than the moment you swab your cheek or spit in a tube. 

This article was originally published in the November 2017 Trail Living Magazine and is published with consent of the editor.

When your friend becomes your own Genetic Counselor: the Base Pair series continues with Lola and Stephanie

With the Base Pair series on my blog, I aim to put faces to the professional title of "Genetic Counselor" and share the stories of my fellow genetic counselors, especially for those who perhaps have never met or spoken with one of us. There are thousands of masters-trained genetic counselors in the United States and worldwide, and our stories and the work we do are as diverse as the DNA we carry. The newest Base Pair, Stephanie Cohen and Lola Cook Shukla, have been friends and coworkers for years and once stepped into the roles of patient and care provider. I asked the two to share their story, and what makes their relationship unique.

How did you get interested in genetic counseling?

Stephanie:  I was working in a genetics laboratory doing basic research during a college summer, and I HATED it…..I was a little freaked out about what I would do with my biology degree because I knew I didn’t want to go to medical school and wasn’t cut out for bench-side research.  I passed by a poster every day  in the hallway of the biology department at CWRU – “What can you do with a biology degree?”, so I ordered a copy for my dorm room.  I stared at it every night, and the two careers that stuck out to me were “mushroom farm worker” (really??) and “genetic counselor” (interesting!). I was intrigued because I had always like genetics, and I like the idea of working with people.  I contacted our guidance office, they helped me track down a genetic counselor at University Hospitals.  After speaking with her for 15 minutes, I knew that was what I wanted to do!

Lola: In my high school biology class. I had a very progressive teacher who was already aware in 1982 of the potential role of genetic counselors. Over a model of a human skeleton, where I was reciting bones, he told me I really needed to do more with myself!

Did you learn about genetic counseling from someone you knew, or did you influence someone else to attend school for genetic counseling? 

Stephanie:  I hope I have influenced someone!  I have had a lot of students job-shadow me over the years, and I know several eventually went on to become genetic counselors (I can name at least 5). Claire Harwood, a current rock-star co-worker, shadowed me a few times while she was in college, and then volunteered as an intern in our office for a year before being accepted to graduate school. I can’t say that I influenced her to become a genetic counselor because I’m pretty sure that’s what she wanted to do when she first met me, but at least I didn’t drive her away, and she ultimately came back to work with us!!

 Lola: I am constantly urging others to consider the field of genetic counseling or other genetic careers. It is a hot profession and has much potential to do good for others!

What is your special connection to your Base Pair buddy? How did you meet?

Stephanie: When I moved to Indianapolis, Lola was one of the few other genetic counselors in town.  We met at the inaugural meeting of what ultimately became the Indiana Network of Genetic Counselors. A friendship developed over the years, beyond a collegial relationship, that includes regular get-togethers with a few other well-seasoned genetic counselors. Lola covered a maternity leave for me, adding a cancer genetics hat to her experience and taking good care of patients for me during my absence.

Professionally, we’ve worked on many projects together, including the passage of licensure in the state of Indiana and developing resources for the Indiana Network of Genetic Counselors. We’ve been a sounding board for one another over the years throughout career and personal life changes. I admire Lola’s fearless ability to take on new areas of expertise, learning what she needs to know completely and with great dedication. She is a true advocate for patients and our profession.

Lola: I know Stephanie as a good friend and top-notch cancer genetic counselor. I think we met through our overlapping jobs at a local hospital, but I really do not remember well! We go out socially for dinner with three other genetic counselor friends in the area who have bonded over the years. At our genetic counselor dinners, we laugh, talk work and family. Workwise, I know Stephanie from taking a prenatal job in the same maternal-fetal medicine department where she counseled prenatal and cancer patients. Thus, we have a work connection as well. I covered several weeks for her during a maternity leave counseling patients in the familial cancer risk center where she now works. I gained a huge and new respect for what she does as I witnessed the emotions of patients and families who had gone through so much as they dealt with familial cancer and risks to their relatives.

What’s the unique aspect to your relationship beyond being coworkers and friends?

Stephanie: I have had the privilege of providing genetic counseling to Lola for her family history of cancer. She was sweet to consider if I would feel uncomfortable in this role, considering the potential that I may have to give her difficult news. It is courageous to open your private life and past history to any medical professional, and can be even more difficult with a friend and colleague. I was honored and humbled that Lola would feel comfortable doing this with me. We had a frank conversation prior to her appointment about this, reassuring each other that we each felt comfortable in this different relationship.  

Lola: I began thinking more about my risk for cancer after my father developed his 4th primary cancer and my mother was diagnosed with breast cancer. I began asking Stephanie questions informally about my family history of cancer and what she thought.  As the years passed, more knowledge and genetic testing became available and I then made an appointment with her in the familial cancer risk center to formally talk about my cancer risk and testing options. Eventually, I decided to proceed with testing. I was worried about Stephanie potentially having to give me “bad news” from my test results. I did not want her to feel bad as a friend. She was great talking this out with me during our counseling session. It truly was a gift to have such a wise, open, and good friend to handle sensitive information and feel comfortable with it!

We both are lifelong learners and get very excited talking to each other about the changes in genetics and our field. We also enjoy sharing Indian and other exotic foods!

Stephanie and Lola enjoy a quiet dinner out, with kids and spouses back at home!

Stephanie and Lola enjoy a quiet dinner out, with kids and spouses back at home!

More about Lola and Stephanie:

Lola Cook Shukla is a genetic counselor with a broad background who has worked in pediatric, prenatal, and adult genetics. She also has worked in industry as a medical research analyst. Currently, she specializes in the genetics of Parkinson's disease, providing remote genetic counseling to participants who are part of a large Parkinson’s disease research study, sponsored by the Michael J. Fox Foundation. Lola is interested in new and innovative ways to provide genetic counseling services and serves on a working group developing practice  guidelines for telegenetics for the National Society of Genetic Counselors (NSGC) and also will be serving as co-chair of NSGC’s Health Information Technology  Special Interest Group (SIG) this upcoming year.

Stephanie Cohen is a genetic counselor who provides in-person and remote genetic counseling via telemedicine for hereditary cancer risk at St. Vincent Health in Indianapolis. Stephanie is interested in improving access to cancer genetic services, and serves as the chair of the National Society of Genetic Counselor’s Service Delivery Model subcommittee. She is active in training genetic counseling students as an Adjunct Assistant Professor at Indiana University as a clinical supervisor and co-instructor for a Cancer Genetics course. She has multiple publications in the field of cancer genetics and genetic counseling service delivery.


Like reading the Base Pair series? Read about my first two couples - a husband/wife couple of genetic counselors who met in graduate school and sisters-in-law who earned their degrees at different times.

Know a pair of genetic counselors who share a unique relationship? Perhaps two GCs who job-share or who work as a pair to cover the needs for an institution or geographic region? Send your recommendations to me, and maybe you'll see them highlighted in a future post!  

From the National Society of Genetic Counselors: Answers to Six Important Questions about Genetic Counseling

“Many people are confused about what a genetic counselor does, and many who might benefit from seeing a genetic counselor may not know we exist,” said Mary Freivogel, president of the National Society of Genetic Counselors (NSGC).

DNA Testing After a Stem Cell Transplant: a Fascinating Case

When you have an allogeneic bone marrow or stem cell transplant, the blood-producing cells in your bone marrow are killed off by radiation or chemotherapy and then replaced with functioning cells from another person. The technical term for this process is allogeneic hematopoietic cell transplantation

In allogeneic transplants, DNA from your “donor” (the person donating the replacement cells to you) travels along inside the cells that get transplanted, and you become a chimera at that point. (A transplant with your own cells is called an autologous ["self proportion"] transplant and does not affect your DNA makeup). After a donor’s cell take root in your body, you now have two separate sets of DNA represented in your tissues. Which results come back when you have a DNA test after your transplant depends on which cells get tested. The complexity of this situation makes it easy to understand how this has become the storyline of more than one crime scene investigation show on TV!

This type of acquired chimerism is distinct from the rare form chimerism present at birth -- congenital chimerism. Congenital chimerism happens when someone is born already having two distinct sets of DNA. It is thought to be caused by fraternal twin embryos joining early on in pregnancy to form one person. In a way, it is the inverse of identical twinning, when one egg splits into two. Congenital chimerism has only been documented in a few cases including the well-publicized case of Lydia Fairchild and one case I was involved in professionally just a few years ago, described in this Time magazine article here.

Acquired chimerism is growing more and more common with stem cell transplants being an available treatment for a number of conditions like lymphoma, leukemia, and sickle cell disease. Some hypothesize that the rise in fertility treatments for pregnancy conception might also be increasing the number of individuals born with congenital chimerism (due to increased twinning rates at conception); however, this theory has yet to be studied and tested.

Doing DNA testing on people who have already had a stem cell or bone marrow transplant can get tricky. Because there is interaction between the blood stream and types of cells lining the cheeks and because cells from your blood stream can get into your saliva, we actually can find both sets of DNA when we do a test on saliva or a cheek swab. Per multiple testing companies, this often causes the test to result in “failure” for many people who have been through a transplant. 

Here's what 23andMe wrote in response to a customer question on the topic:

"If you have received a bone marrow transplant, we cannot recommend that you use the 23andMe® Personal Genetic Service (Ancestry Service or Health & Ancestry Service).
The saliva sample required to receive the 23andMe Personal Genetic Service includes DNA from multiple cell sources, including epithelial cells from your cheeks and mouth and white blood cells from your saliva. As a bone marrow recipient, your blood cells will contain the DNA from your marrow donor, while your epithelial cells contain your own DNA. The combination of DNA sources frequently results in analysis failure. In the event that the analysis was successful, it still would be unclear whether the results were based on DNA from you or from your donor."

What I recently learned is that in some cases, the sample doesn’t fail! I had a gentleman ("Tom") reach out to me who had tested both prior to and after his stem cell transplant. When he took the raw data from his pre- and post-transplant DNA tests to the website GEDmatch.com and ran analysis of his DNA against other people in his family, the results were surprising. And yet, knowing the history of his transplant and who in his family was his donor, the results were not surprising. They actually made a lot of sense!

I am going to show you how this gentleman matched two people in his family along chromosome number 1, and I want you to guess which family member -- his sister or his son -- was his stem cell donor. 

If you are new to learning about GEDmatch, this is going to be more challenging for you! But hang around and give it a try. You might be able to figure it out even if you’ve never used GEDmatch before.

Tom and his sister before the transplant

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Tom and his sister after the transplant

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Tom and his son before the transplant

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Tom and his son after the transplant

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Here's a key to understanding the color coding in GEDmatch:

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Did you figure it out?

Tom’s sister was his donor! So now Tom is a chimera, with some of the DNA he was born with and his own sister’s DNA present in some of his cells. All that we see in his raw data file now, however, is his sister's DNA.

Tom was happy to share his story but has a word of advice:

If I had one thing to tell people going through a transplant, it would be to have a DNA test done prior to the transplant for history’s sake.

If you wait until after a transplant and then try to do a DNA test like 23andMe or AncestryDNA, you might forever lose the opportunity to have a true reflection of the DNA you were born with. This also means you may lose out on the opportunity to explore how your DNA matches other people, including your children, siblings, and future generations. 

Thanks for sharing your story and your images for the benefit of my readers, Tom! I am so glad your transplant was a success and wish you many healthy, happy years ahead.


Resource for Learning about Medical Genetic Testing

If you are a blogger, writer, or speaker who covers the topic of genetic testing, and the topic of medical genetic testing or consumer-based testing with medical implications ever comes up, please stop and read this!

Over the past year, I've been working with a group of genetic counselors on behalf of the National Society of Genetic Counselors to gather, summarize, and explain the various aspects of genetic testing that commonly lead to confusion and concern.

We developed a summary document called the "Genetic Testing Resource" listed in the section of the website aboutgeneticcounselors.com. See the screenshot below for where to find it.

Find the document at http://aboutgeneticcounselors.com/Genetic-Testing, where the orange arrow points. 

Find the document at http://aboutgeneticcounselors.com/Genetic-Testing, where the orange arrow points. 

The aim of the document is to address in everyday language the common questions (and myths) about genetic testing for medical purposes. Some of the many topics addressed in the 16-page document include:

·      Types of DNA that can be tested

·      Different DNA technologies and their usefulness

·      What exactly is “informed consent” for genetic testing?

·      Where do genetic counselors fit in the picture?

If you write about DNA online or in books or speak to audiences, please be extra cautious about the advice you give to others regarding medical information from consumer DNA tests (and especially the raw data to come from them). You are welcome to use quotes from this document as long as you cite it as your source.

Reports produced from raw data files from the consumer testing market and clinical genetic tests are not the same, and it’s critical that if you choose to comment on health topics, you understand how, and why. The “Genetic Testing Resource” will give you a good start.

I’m a consumer of at-home DNA testing many times over. I understand the appeal, and I understand the desire to gather medical information from any test where it’s possible.

I’m also rooted at the intersection medical genetics and consumer testing and see the benefits and limitations from an insider perspective. I don’t discourage people from pursuing information that is important to them, but I encourage everyone to learn as much as possible about the differences between types of testing and the results to come from them.

There is a lot of information that can mislead and confuse. I want you to get accurate and useful medical information, whether you chose a test from the consumer market or opt for a clinical-grade test.

Want to learn more? I've written more about "raw data" topics herehere, and here. Check out those posts if you want to learn more! 


How to enroll in "All of Us"

I received a great question through my website today: "How can I enroll in All of Us?"

If you're interested, visit this site: https://www.joinallofus.org and sign up for more details by clicking the "join now” button.

The project is in "beta testing" with 2,500 participants across 50 sites, to get the system up and running. According to this recent Genome Web article, the project will be opening to additional participants in spring 2018.

If you sign up now, expect to receive update emails that will give you more information over time. The All of Us website and Twitter are how I receive my updates, so I don't have any tips or insider info to share. 

Will signing up now lead to an earlier chance at enrollment? Not sure. But if you like to line up early for the best seat in the house, or generally live your life as the early bird going after the worms, I guess there's no harm in trying!