- Design
- Retrospective analysis of a variant-classification framework across its versions
- Population
- 2.6 million variants from 5.5 million individuals referred for genetic testing
- Primary outcome
- Change in variant-of-uncertain-significance rate and reclassification
- Effect
- 73% of tracked reclassifications used post-baseline criteria; score predicted reclassification direction (r-squared 0.95)
Variants of uncertain significance are the bane of clinical genetic testing, and how classification rules evolve directly changes how many a laboratory issues. This analysis evaluated a decade of a points-based refinement of the 2015 ACMG/AMP guidelines, applied to 2.6 million variants across 5.5 million people referred for testing.
Tracking a set of 32,241 variants first classified under an early version, 3,834 uncertain variants were later reclassified; 73% of those reclassifications relied on evidence criteria added after that early version — showing that the framework updates, not just new data, drove the gains. In a simulation removing later artificial-intelligence-related criteria, 21% of recent classifications changed, and the numerical score predicted the direction of reclassification well.
The lesson for a reporting laboratory is that structured, points-based classification systems materially reduce uncertain calls over time, and that a variant's score carries quantitative information about how likely it is to be reclassified. This is one commercial framework's experience, so the specific numbers are not a universal benchmark.
- Points-based refinement of the 2015 ACMG/AMP guidelines applied to 2.6 million variants across 5.5 million people.
- Of 32,241 tracked variants, 3,834 uncertain ones were reclassified; 73% relied on criteria added after the early version.
- Removing later AI-related criteria changed 21% of recent classifications in simulation.
- The numerical score predicted the direction of reclassification well.
- Structured scoring reduces uncertain calls, but these figures are one framework's experience.
Why it matters
It shows that how a laboratory structures its classification rules, not only the evidence it gathers, changes how many uncertain results patients receive.
Don't overread it
This reflects one commercial classification framework; the specific reclassification rates are not a universal benchmark for other laboratories.
The statistics, in plain English
These are operational metrics from one laboratory's framework, not a trial; they show the direction and scale of change in classification, but the exact percentages depend on that system and its caseload.
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