CJG Blog

Center for Jewish Genetics blog

How much credibility should you give to the results of a single DNA ancestry test?

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Arms 3

By Carol Guzman

With the rise in direct-to-consumer tests like 23andMe or Ancestry DNA, people can seemingly easily discover their biological roots. While many are not fazed by the results, which often confirm with a family’s vague oral history of itself, others see their findings as life-altering news that makes them question who they really are. A recent New York Times Magazine report followed one woman’s experience receiving test results that didn’t match who she believed herself to be.

Sigrid Johnson is one of the more than 7 million people who have taken the popular at-home tests, which promise to reveal ancestry and distill ethnic composition down to a pie chart. Johnson, whose biological father was black and biological mother was white, expected her DNA results to show she was half African and half Italian. When she took the test in 2015, her results showed she was 45 percent Hispanic, 32 percent Middle Eastern, 14 percent European, and 9 percent “other” – which included 2.9 percent African ancestry.

That 2.9 percent figure shocked Johnson. She told the Times the results made her afraid others in her community would think she was a fraud. “How can I not be black?” she said. “I lived black. I was black.” Johnson is not alone in this experience.

Earlier this year, Sen. Elizabeth Warren released her DNA results confirming that she has Native American ancestry after facing criticism from political rivals for listing herself as a minority in professional directories while working at Harvard Law School. Rather than relying on a direct-to-consumer test, Warren solicited help from Dr. Carlos Bustamante, a renown genetics specialist and advisor to Ancestry.com. He concluded that there was strong evidence of Warren having a Native American ancestor 6 – 10 generations ago. The Cherokee Nation disapproved of Warren’s course of action, claiming her use of ancestry testing as inappropriate and undermining tribal interests. The criticism and uproar were so intense that many on the left and right questioned whether her decision would impact her potential 2020 presidential campaign.

In August 2018, House Speaker Paul Ryan discovered he had Jewish roots while filming PBS’ “Finding Your Roots with Henry Louis Gates Jr.” While Ryan never knew of his Jewish ancestry prior to the show many Jewish people criticized him for not upholding Jewish values. Unlike Warren, Ryan wasn’t denounced for claiming a Jewish heritage but for not being Jewish enough.

During Hanukah Sen.- elect Alexandra Ocasio-Cortez revealed that after investigating her family history she learned her ancestors consisted of Sephardic Jews. She further explained that Puerto Ricans are descendants of Spanish colonizers, indigenous peoples, and Jewish refugees. Anticipating backlash, the incoming senator tweeted, “Before everyone jumps on me – yes, culture isn’t DNA.”

Ocasio-Cortez’s Tweet rings true: Judaism is not defined by specific percentages in our genetic code but rather how we choose to celebrate and honor our Jewish culture and religion. But it also raises a larger question: what is the relationship between our genes, our culture, and our identity? Consider individuals of Jewish ancestry, who have a higher risk of being carriers of genetic disorders whether they chose to identify as Jewish or not. And yet a convert considers Judaism a core part of their identity without having any Jewish ancestry. 

Sigrid’s core identity should not change just because her DNA test results do not align with the way she chooses to live her life. Ancestral testing is limiting and does not determine whether an individual has the authority to claim a heritage or culture.

Ancestry testing can be fun but does not provide a comprehensive picture of our identity and certainly is no substitute for health risk testing. For questions about carrier screening, cancer risk testing or other clinical genetic tests, please contact that Sarnoff Center.

Why I’m Thankful for Three Thanksgivings

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By Sarah Goldberg

Growing up with divorced parents, the Thanksgiving holiday was always a little complicated. When you’re Jewish, almost every holiday you celebrate has two (or more) nights – one for each parent. But Thanksgiving is just a single day and night. One particularly memorable year in college, my sister and I celebrated three Thanksgivings: holiday lunch with mom’s side, turkey dinner with dad’s family, and then pumpkin pie with a cousin who was hosting her in-laws.

As hectic as it was, three Thanksgiving celebrations meant more chances to reflect on what I felt thankful for, and more of what I consider the best meal of the year (I can’t get enough sweet potato casserole with marshmallows on top). More importantly, I spent the holiday enjoying time with pretty much my entire family – parents, grandparents, aunts, uncles and cousins on both sides. It was a perfect day to piece together my family health history.

Like many Jewish families, when my relatives and I get together, we share stories and eat traditional meals cooked from recipes that have been passed down for generations. But we don’t talk nearly enough about another piece of our family history: health conditions that may be inherited, too. I might know that my uncle has one health affliction and my grandma passed away from another, but different family members have other knowledge and together we hold more pieces to the puzzle. Putting it all together can help us protect our health and the health of our loved ones.

The Thanksgiving holiday brings families together – whether you have three celebrations, like me, or it’s a simpler affair – to pause and reflect. This year, take the time to reflect on your family health history as well. Discuss your own information, ask questions of other family members, compare notes, and, ultimately, share this knowledge with your healthcare provider and encourage your relatives to do the same. Hopefully, these conversations will help to keep us thankful for our health for years to come.

Happy Thanksgiving!

Not sure how to get started? Learn more about family health history and find tools and worksheets to help you collect key information on our family health history page.


Moving Forward: Using Our Community Needs Assessment to Inform Our Work

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By Becca Bakal, MPH

Welcome to the final installment of our blog post series about the Norton & Elaine Sarnoff Center for Jewish Genetics Community Needs Assessment! In the past, we’ve shared:

On the agenda this time: how we’ll move forward with what we learned from the Community Needs Assessment. We’re refining how we raise awareness about Jewish genetic health topics in both Jewish and secular settings. Our vision is to empower the Jewish community, starting in Chicagoland and moving outward, to take ownership over their health. We hope to:

  • Equip folks with greater knowledge of their genetic health risks
  • Provide resources and support to help people start conversations about family health history
  • Ultimately lower barriers to seeking genetic counseling and medical screenings if warranted

As we look forward, the community needs assessment will serve as a guide for the development of educational resources and supports. The Sarnoff Center has already been an educational resource for Jewish communities for almost 20 years, and we’re expanding our educational offerings and tools.  Based on our findings, we developed best practice recommendations that cover four dimensions: Messaging, outreach, programming, and assessment. 


  • Emphasize empowerment and that people can act to prevent Jewish genetic disorders and hereditary cancers
  • Focus on family health history (FHH): How to take an FHH, the benefits of learning about FHH
  • Make Jewish genetic health personal: Share how it is relevant to my life
  • Address and dispel misconceptions about Jewish genetic health


  • Reach people where they are: Go to Jewish events, emphasize peer education and education through family members
  • Provide resources and support to rabbis, healthcare providers and therapists around Jewish genetic health
  • Strengthen partnerships with Jewish institutions and health institutions to get Jewish genetics on the agenda


  • Develop small-scale educational programs tailored to various audiences
  • Design activity-based education in a variety of media, to be delivered both in-person and virtually


  • Assess educational needs of rabbis and healthcare providers, including therapists
  • Assess the feasibility of developing a peer education program
  • Integrate assessment of pilot educational programs into ongoing program evaluation

As we develop educational supports, we’ll use these recommendations as guideposts.

Thanks again to all who participated in the community needs assessment and for those of you following along. We look forward to your continued partnership as we pilot and refine new educational tools.

Interested in learning more? You can download the needs assessment here.

Genetic Diversity in Genetic Studies

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Genetic Diversity

By Carol Guzman

Advancements and discoveries in genetic research and technologies intentioned to help all humans only benefit few. Since the completion of the Human Genome Project in 2003, researchers have sequenced the genomes of various populations all over the world (see: 1,000 Genomes Project). Yet little population-specific research has been conducted to advance the knowledge of disease and personalized medicine in minority groups.

Genome-wide associate studies (GWAS) allow scientists to study and identify genetic markers that are involved in human disease. GWAS compare one group of healthy individuals against a group of individuals affected by a specific disease. In these studies, scientists look at several small gene changes called single nucleotide polymorphisms (SNPs) in both sample populations. GWAS has been used to study genetic factors that contribute to many common, complex conditions such as diabetes, heart disease, and drug metabolism.  The small genetic differences found in the affected group versus the unaffected group help scientists identify genetic variants that may be associated with an individual’s risk of developing a specific disease. After GWAS are used to pinpoint genetic markers associated with diseases, scientists can use this information to guide drug development that treats the root cause of the disease rather than only treating the diseases’ symptoms.

According to a study conducted by Nature, of 2,511 GWAS involving 35 million participants, 81% of participants were of European descent. Of the 19% of non-European ancestry samples, African and Latin American ancestry, Hispanic people and native or indigenous people represented less than 4% of the participants the GWAS studies. Therefore, researchers are developing drugs and other targeted therapies based on disease-associated genetic markers that are typically found in only European populations. Failure to include minority populations results in undiscovered genetic variants associated to diseases. These exclusions make it impossible to make drugs that could treat the root causes of minority genetic variants.

However, finding genetic markers associated for a disease is not as easy as diversifying the population of those participating in the study. The small genetic differences that would be identified could also be natural genetic variation related to differences in race or ethnicity, as opposed to variants associated with a disease. Therefore, we must have global genomic studies to ensure that personalized medicine benefits all human populations. The National Institutes of Health is making a historic effort to gather data from more than one million people in the United States. Their All of Us Research Program will enable researchers to conduct genetic studies on various minority populations in the United States. Still, similar initiatives have yet to be seen on a global scale.

Genetic diversity also plays an important role in better understanding genes that are known to causes certain diseases, such as genes related to hereditary cancer risk. The Jewish population has an increased risk of having a gene mutation that leads to higher breast cancer risk. Knowledge of specific Jewish genetic variants has helped widespread hereditary cancer screening efforts within the Jewish community. African women are also more likely to develop breast cancer compared to the general population. However, it was only this year that University of Chicago conducted the first study focused on understanding genetic variants for breast cancer in African populations. Among African women, breast cancer is diagnosed at later stages, is more frequently a triple-negative disease, and is far more frequently fatal compared to women of other of other ethnicities.

While in some ways the Jewish population remains at the forefront of genetic screening we too suffer from the marginalization instituted from lack of diversity in genetic research. A clear example is the W1282X nonsense mutation of cystic fibrosis, a variant of CF that is highly prevalent among Ashkenazi Jews. This CF genetic variant affects 5-10% of CF cases worldwide. Researchers have created drugs that help 90-95% of CF patients with the most common CF mutations, but none have been made to help those suffering from CF by way of this particular nonsense mutation.

Modern day Jews come from various ethnic Jewish origins resulting in several Jews having different genetic variants of various diseases. By integrating minority populations in genetic studies to improve screening and genetic medicine, the scientific community benefits Jews and the world.


Affordable, Accessible Genetic Screening in Illinois

Our affordable, accessible carrier screening program uses advanced technology to provide comprehensive screening for Jewish and interfaith couples. Visit our Get Screened page to learn more and register.


Do You Know What's In Your Genes?

What is the most valuable gift you can give to your family? The gift of good health! There are many health conditions that run in families. Knowing your family health history can alert you to the potential risk for a variety of genetic disorders . Talk to your relatives for warning signs and assess your risk for hereditary cancers.

Did you know: Ashkenazi Jews are 10 TIMES more likely to have BRCA mutations, which significantly increases lifetime risks for hereditary cancers, so what does this heightened risk mean for you? Click here to learn more .