Anne has Ashkenazi Jewish Ancestry. She is aware of genetic studies of Ashkenazi Jews that have examined their relationships and migrations, and she is also aware of genetic studies that reveal increased prevalence of certain genetic diseases among Ashkenazi Jews. Anne was excited to learn of a first-year seminar that provided an opportunity to obtain genetic test results from 23andMe. Anne didn’t hesitate when it was time to spit into the tube and send off for a DNA test. She thought it would be interesting to see what proportion of her ancestry traced to the Ashkenazi Jews of Europe. After a month when Anne’s test results were available on the 23andMe website, she wasn’t too surprised with the Ancestry Composition report estimating 32% Ashkenazi ancestry. Over the fall break Anne was discussing her 23andMe results with her parents and they asked if the report included medically relevant information. She informed them about the FDA ban on 23andMe reporting this information. “That’s too bad” her dad said, because I had a cousin with Tay-Sachs disease and it would be beneficial to know whether you’re a carrier. By the end of the semester, Anne had learned to navigate her genome and look at individual genotypes. She decided to look at the SNP in the HEXA gene commonly associated with Tay-Sachs disease, and sure enough her genotype was reported as GC – she is a carrier of the disease-causing allele. Fortunately, the disease appears only in individuals that have the disease-causing C allele on both chromosomes.
Are you aware of the FDA action against 23andMe, and do think that a company should be allowed to provide information directly to customers about health risks?
Why is it that Anne’s Ashkenazi Jewish ancestry prompted her to investigate whether she was a carrier of Tay-Sachs?
What other genetic diseases are more prevalent in some populations compared with others?
In her senior year of college Anne started dating Ben, who also had Ashkenazi Jewish ancestry. After dating a few years they married and started planning to have children. Anne thought back to learning that she was a Tay-Sachs carrier in her first-year seminar and asked Ben whether he had ever done a genetic test. He had not.
Does Anne’s carrier status indicate that children she and Ben have are at risk of developing Tay-Sachs disease?
What actions could Anne and Ben take as part of their family planning?