Can Genetic Test Results Vary for the Same Patient?

Insights | 25. 05. 23

Yes—even if the same patient takes the same exome sequencing test, the results can differ depending on several key factors. This might sound surprising, but it’s a reality in clinical genetics that many patients and healthcare providers are not aware of.

Understanding why these differences occur is essential when choosing the best genetic testing lab for accurate, reliable results.

How Choosing the Right Genetic Test Can Change Patient Outcomes – Not All Exome Sequencing Tests Are the Same

Differences in Exome Capture Kits

Even when the raw sequencing data is the same, the interpretation process can lead to different results.

Labs differ in their variant classification criteria, reference databases, and algorithms.
A variant that one lab labels as “uncertain” may be considered “pathogenic” at another based on newer data or clinical experience.

At 3billion, all cases are reviewed by experienced clinical geneticists with deep expertise in rare diseases.

Differences in Timing and Reanalysis

Genetic knowledge is constantly evolving. A variant with no known association today might be linked to a disease tomorrow.

Without regular reanalysis, patients may miss out on new diagnoses.
Most labs don’t reanalyze unless requested—and often charge for it.

3billion performs routine reanalysis, diagnosing 30–40 new patients every month without additional testing or fees.

How to Choose the Right Genetic Testing Lab

When comparing genetic test providers, ask these questions:

What is the exome capture range?: Look for comprehensive coverage, including mitochondrial DNA.
Does the lab have experienced clinical experts?: Check for board-certified geneticists and a proven diagnostic track record.
Is reanalysis included and automated?: Continuous reanalysis increases diagnostic yield without extra effort or cost.

3billion has diagnosed over 75,000 patients across 60+ countries, offering end-to-end interpretation and reanalysis powered by AI and expert review.

How Choosing the Right Genetic Test Can Change Patient Outcomes

Imagine a child undergoing testing and receiving no diagnosis. Months later, as genetic science advances, a reanalysis leads to a definitive diagnosis—enabling proper treatment, support, and relief for the family.

This is why choosing the right testing lab matters. It’s not just about running the test—it’s about interpreting it with care, expertise, and staying up to date.