atlageneNote
Reading coverage: why every result says how much the file measured.
Two reports can both say “no findings” in a category and mean very different things. Coverage is how you tell them apart.
What coverage is
Each category has a panel: the positions its variant definitions look at. For a given file, the analysis checks which of those positions the file actually measured. Coverage is that share, the measured positions out of the panel’s positions.
Why it matters
No findings at high coverage tells you something about the positions the panel looks at. The same result at low coverage mostly tells you that the file did not look. Without coverage beside it, both read as reassuring.
Unmeasured is not normal
A position the file did not measure is left out of the result. It is not scored, and it is never shown as a normal finding. That keeps a gap in the data from turning into false reassurance.
How to read a thin result
Read each category’s result together with its coverage. When coverage is low, the right conclusion is “not assessed”, not “low risk”. Coverage describes what this file measured, not what the laboratory could measure with a different test.