The Genome Becomes Part of the Diagnostic Workup
Mayo Clinic’s Tapestry Study has demonstrated that next generation genetic analysis can have a significant impact on patient care.

By John Halamka, M.D., President, Mayo Clinic Platform and Paul Cerrato, MA, senior research analyst and communications specialist, Mayo Clinic Platform
On April 14, 2003, the world learned that the Human Genome Project had been completed. As the National Institutes of Health pointed out, it was one of the greatest scientific accomplishments in history and the first completed sequence of the human genome, the DNA that determines not only the color of our eyes, but our susceptibility to many diseases. Unfortunately, many clinicians were disappointed when they realized the data didn’t have an immediate effect on routine patient care. Why not?
As it turns out, most human diseases are not caused by mutations in a single gene, but by the interaction of many genes, as well as an individual’s lifestyle and the environment they are exposed to. Similarly, diseases that have a genetic component that includes a specific mutation that greatly increases the risk of disease are often overlooked until they become symptomatic. With that in mind, Mayo Clinic conducted a large-scale, decentralized, clinical study—the Tapestry Study—to determine to what extent genetic variants actually influence patients’ risk of disease, and to find out what actionable mutations might arise when a large group of patients undergo whole exome sequencing of the genome. The genome refers to the complete genetic information in a person’s cells while the exome is that portion of the genome that codes for the proteins that the body makes; it makes up only about 1.5% of the genome.
The Tapestry Study examined the exome of over 98,000 Mayo Clinic patients by extracting DNA from their saliva. In addition to whole exome sequencing, the researchers tested the samples for about 300,000 single nucleotide polymorphisms (SNPs). SNPs are genomic variants located as a single base position in the DNA.
The investigators analyzed the genes that have been linked to certain diseases, including hereditary breast, ovarian cancer syndrome (BRCA1/2), Lynch syndrome, a hereditary form of colorectal cancer, and familial hypercholesterolemia. They identified over 1,800 patients (1.9%) who had actionable pathogenic or likely pathogenic variants. About half of this group had BRCA 1/2 mutations, 28.4% had genes associated with familial hypercholesterolemia, a condition that greatly increases the likelihood of early onset heart disease, and 22.2% had the genes for Lynch syndrome.
To put these statistics into perspective, the CDC says about 2 million persons in the US are at increased risk from pathologic or likely pathologic genetic variants related to hereditary breast and ovarian cancer, Lynch syndrome, and familial hypercholesterolemia. Since these diseases rarely show themselves with signs and symptoms until they are at an advanced stage, screening large populations may be the best way to spot those in need of intervention and genetic counseling to help them decide how to manage that risk. In the Tapestry Study, patients who received the news about their disease-related mutations were given detailed advice from certified genetic counselors and relevant educational materials.
Lorelei Bandel and her associates point out that the data from the Tapestry Study will not only improve patient outcomes. It will also be made available to researchers across an array of diseases for studies and scientific discoveries. And finally, the Tapestry team is collaborating with Mayo Clinic Platform to make the Exome + data available to its partners as de-identified data. That includes healthcare providers, solution developers, and healthcare delivery organizations around the world.
In 2025, Mayo Clinic Platform is ushering in a new era of precision medicine, utilizing unparalleled computing power, global curated multimodal data that includes exomes, and the next generation of discovery tools.
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