Helix DNA testing uses clinical-grade exome sequencing, a method that reads the protein-coding regions of your genome with high accuracy for detecting single-letter DNA changes. The platform has received FDA authorization for specific health-related reports, which means it has passed federal performance benchmarks. But “accurate” depends on what you’re asking: whether the machine reads your DNA correctly is a different question from whether the results are meaningful for your health.
How Helix’s Technology Differs From Most DNA Kits
Most consumer DNA tests from companies like 23andMe and AncestryDNA use SNP microarray chips. These chips check a fixed list of roughly 600,000 to 700,000 known genetic positions, essentially scanning for specific variants scientists have already cataloged. Helix takes a fundamentally different approach. Its Exome+ platform sequences the exome, the roughly 20,000 protein-coding genes that make up about 1.5% of your total genome. Instead of checking a preset list of positions, it reads the actual DNA letters in those regions.
This distinction matters for accuracy in a practical sense. SNP chips are very reliable at detecting the specific variants they’re designed to find, but they can only find what they’re looking for. Exome sequencing can detect novel variants, small insertions and deletions, and single-letter changes that a chip might miss entirely because they weren’t included on its panel. For identifying rare genetic mutations linked to health conditions, exome sequencing generally captures more clinically relevant information.
The tradeoff is that exome sequencing is not ideal for detecting larger structural changes in your DNA, such as big deletions, duplications, or chromosomal rearrangements. SNP-based arrays are actually better at picking up those kinds of copy number variations. Exome sequencing also struggles with trinucleotide repeat expansions (the type of mutation behind conditions like Huntington’s disease) and methylation patterns. No single method catches everything.
Analytical Accuracy: Reading the DNA Correctly
Analytical accuracy refers to how well the lab reads what’s actually in your sample. Helix’s Exome+ platform went through FDA review (filed under DEN190035), and the agency evaluated its ability to correctly identify genetic variants from both cell line samples and saliva samples. The platform requires a minimum read depth of 20X, meaning each position in the exome is read at least 20 times over to reduce errors. Higher read depth generally means higher confidence that a detected variant is real and not a sequencing artifact.
The FDA review assessed “callability,” which is the percentage of targeted positions that met that 20X coverage threshold. Different subsets of the genome, including high-priority disease genes, broader disease-associated gene panels, and all coding regions, each had their own quality thresholds. The specific pass rates were redacted from the public review document, which is standard for proprietary performance data. What we do know is that the platform met the FDA’s standards for authorization, meaning it demonstrated sufficient sensitivity (catching real variants) and specificity (not reporting false ones) across those regions.
For perspective, clinical exome sequencing platforms in general achieve analytical sensitivity above 99% for single nucleotide variants when coverage depth is adequate. The 20X minimum is considered a reasonable floor for clinical-grade work, though many positions will be covered at much higher depth.
FDA-Cleared Health Reports
Helix has obtained FDA 510(k) clearance for specific health risk reports built on its sequencing platform. One notable example is its Genetic Health Risk App for late-onset Alzheimer’s disease, cleared in December 2020 under submission K192073. FDA clearance means the company submitted validation data showing the test performs comparably to an existing approved test for that specific condition.
This is an important distinction. The underlying sequencing platform has its own FDA authorization, and individual health reports built on that platform go through separate clearance processes. A cleared report for Alzheimer’s risk has been specifically validated for that purpose. Other reports on the Helix marketplace, particularly those from third-party partners, may not have individual FDA clearance and instead fall under the category of laboratory-developed tests with different regulatory oversight.
Where Accuracy Gets Complicated
The biggest accuracy concern with exome sequencing isn’t the machine making errors. It’s interpretation. Because exome sequencing reads so much genetic territory, it generates far more data than a SNP chip, and that means a higher chance of finding variants of uncertain significance (VUS). These are genetic changes where scientists don’t yet have enough evidence to say whether they increase disease risk or are completely harmless. On a scale of interpretive complexity, exome sequencing produces substantially more VUS findings than microarray testing.
Researchers have noted that while exome sequencing achieves high sensitivity for detecting variants, it can have poor specificity for certain types of changes, particularly small copy number variants. This means the platform might flag something that looks like a deletion or duplication but turns out to be a sequencing artifact. For these types of findings, confirmatory testing with a second method is sometimes necessary to verify the result is real.
There’s also the question of coverage gaps. Not every position in the exome gets read at the same depth. Some regions are technically difficult to sequence due to repetitive DNA or high similarity to other parts of the genome. If a disease-causing variant sits in a low-coverage region, it could be missed. Helix addresses this by setting minimum coverage thresholds for different gene categories, prioritizing the most medically important genes for the deepest coverage.
What This Means for Your Results
If you’re considering Helix specifically for health-related genetic testing, the sequencing itself is accurate by clinical standards. The platform reads your DNA reliably, and FDA-cleared reports have been validated for their specific claims. Where you should be more cautious is with results that fall outside those cleared reports, ancestry estimates, carrier screening from third-party apps, or any finding labeled as a variant of uncertain significance.
A positive result on a health risk report, especially for a serious condition, should be confirmed with an independent clinical test before making any medical decisions. This isn’t unique to Helix; it’s standard guidance for all consumer genetic testing. The reason is that even a test with 99% accuracy will produce some false positives when applied to millions of people, and the consequences of acting on an incorrect result can be significant.
For carrier status and pharmacogenomic reports (how you metabolize certain medications), exome sequencing has a genuine advantage over chip-based tests because it can catch rare variants that wouldn’t appear on a standard SNP panel. If you carry an uncommon mutation in a gene related to drug metabolism or a hereditary condition, Helix is more likely to find it than a typical consumer DNA kit. That broader detection capability is the main reason to choose exome-based testing over cheaper microarray alternatives.