Two studies find actionable variants in 4 to 6 percent of whole genome sequences
When most people order a whole genome sequencing kit, they have a specific question in mind -- ancestry composition, pharmacogenomics, carrier status for conditions running in the family. What the test also does, by design, is read all 3.2 billion base pairs, including the genes the American College of Medical Genetics and Genomics considers actionable enough to warrant reporting even when nobody asked about them. Two recent population studies have put a clearer number on how often a genome scan turns up one of these unexpected findings. For a consumer considering a WGS kit in 2026, the number is higher than most people assume.
ACMG's Secondary Findings v3.2 gene list, published in 2023 and available on acmg.net, covers 81 genes where a pathogenic variant meets the bar for clinical reporting: evidence that knowing about the variant changes medical management in meaningful ways. The list spans three main disease areas. Cardiovascular conditions account for the largest cluster, including genes tied to hypertrophic cardiomyopathy, arrhythmia syndromes, familial hypercholesterolemia, and aortic aneurysm. Cancer predisposition makes up the second cluster: BRCA1, BRCA2, the Lynch syndrome mismatch repair genes, and about a dozen others. Metabolic and miscellaneous disorders account for the remainder. The criteria for inclusion are deliberately conservative -- a variant in one of these genes is considered actionable because intervening can plausibly prevent early death or serious morbidity, not merely because the variant correlates with a condition.
A 2025 study published in PubMed Central (PMC12027037) applied ACMG v3.2 criteria to whole-exome sequencing data from 3,972 individuals in Portugal and found medically actionable secondary findings in 6.2 percent of the cohort. Cardiovascular disorders accounted for the largest share at 3.0 percent, cancer predisposition for 2.0 percent, and metabolic or miscellaneous conditions for the remaining 1.2 percent. A second study in a smaller Greek cohort (PMC12025642), also published in 2025, applied the same criteria to 280 unrelated individuals and found pathogenic or likely pathogenic variants in 4.3 percent of participants, with a high proportion of LDLR variants -- the gene most commonly implicated in familial hypercholesterolemia. Both studies used diagnostic laboratory cohorts, not random population samples, and that distinction matters: people presenting for clinical genetic testing carry disease variants at a higher rate than the general unselected population. Estimates for apparently healthy adults drawn from large biobank studies tend to land somewhat lower, in the range of 2 to 3 percent, depending on the gene list applied and the ancestry composition of the cohort.
For a consumer buying a WGS kit, the practical question is whether the product they are considering will surface these findings at all. ACMG's secondary findings guidelines technically apply to clinical laboratories running diagnostic tests, and consumer WGS products occupy a wide range of positions relative to clinical reporting standards. Veritas Genetics describes its myGenome product as a physician-supervised clinical WGS with secondary findings reporting, per the company's product documentation. At the other end of the spectrum, Sequencing.com describes its primary deliverable as raw sequencing files -- FASTQ, BAM, and VCF formats -- that customers can upload to third-party analysis tools of their choosing, per the company's product page; whether a given third-party tool applies ACMG v3.2 criteria depends on which tool the customer selects. Nucleus Genomics, SelfDecode, and Dante Labs each describe health-related reporting capabilities, but the specific gene lists, clinical validation standards, and physician-review workflows behind each product differ enough that a prospective buyer should read the reporting documentation for the specific kit before ordering.
What 4 to 6 percent means in practical terms: a family of four ordering WGS kits should expect roughly even odds that at least one of them will receive a secondary finding flag, assuming a healthy-adult rate somewhere in that range. Most such flags will be cardiovascular -- particularly LDLR variants, which cause familial hypercholesterolemia in roughly 1 in 250 people according to population estimates cited in European Atherosclerosis Society consensus documents. A secondary finding on one of the 81 ACMG genes is not a diagnosis; it is a variant classification that changes the conversation a person should be having with a clinician. A BRCA2 flag does not indicate a cancer is present; it means that elevated-surveillance protocols and risk-reduction options become relevant discussions to have with a physician. An LDLR flag may surface a lipid management conversation that standard bloodwork has been missing for years. The population data suggests these conversations will be relevant for a meaningful fraction of WGS kit buyers -- which makes understanding the secondary-findings reporting policy of any kit under consideration considerably less optional than it might initially appear.