v2 CN: real-data validation vs NYGC 30x SVs (interim), noise gate on normalised LRR (K-027)

GSE165845 360 arrays: constitutional DEL/DUP calls 77/74 % in the NYGC SV truth, LOH
reproduced across replicates 74 %; mosaic calls are mostly false positives (12-23 %),
sensitivity for 25 kb-1 Mb events 7-13 % at QUAL >= 20. All samples had been flagged
SampleQuality by the summary logr_dev (cluster-file mismatch); the gate now uses the SD
of the LRR after the batch reference. Validation script: --ignore-filter.

docs/known_unknowns.md

@@ -4,6 +4,7 @@ Plan §20 lists the open questions; this file records what the implementation ha
 
 | ID | Date | Topic | Finding | Status |
 |---|---|---|---|---|
+| K-027 | 2026-09-29 | CN/LOH (v2) | CYTO-014 noise gate: the summary `logr_dev` also measures cluster-file mismatch (GSE165845: 0.246, all samples `SampleQuality`) while the LRR used after the batch reference has SD ≈ 0.1; the gate now uses the SD of the normalised LRR (the JSON still reports the summary value). Spec: built-in mask/cytobands from UCSC; the annotation bundle uses UCSC ncbiRefSeq instead of RefSeq GFF + Ensembl GTF + HGNC. Real-data result: constitutional DEL/DUP calls 74–77 % in NYGC truth, mosaic calls mostly false positives. | Open: mosaic calling needs rework (`docs/validation/V2_cn.md`). |
 | K-026 | 2026-09-29 | Methylation QC (v2) | Spec deviations: vendor EPIC manifests put a 5th field on some control lines (≥ 4 fields accepted); detection p follows sesame's pOOBAH (1 − max(F(M), F(U))) rather than the ambiguous "1 − ECDF(M + U)"; minfi-style `Sentrix_ID`/`Sentrix_Position` sheet keys accepted. Against sesame 1.28.1 on minfiDataEPIC: β r = 0.99998 (max \|Δβ\| 0.011), detection calls 99.1 % identical, noob signals within 0.5 % (median) / 5 % (max). The systematic remainder is unexplained; it is not the negative controls (sesame did not attach the supplied control table). | Open; `docs/validation/V2_methylation.md`. Next step: dump sesame's background vectors and noob parameters to find the difference. |
 | K-025 | 2026-09-28 | Scaling limits (P9) | With the Rust kernels a Graviton3 core genotypes 78–80 GSA samples/min. At > 8 workers a 125 MB/s gp3 volume caps the run at ~620 samples/min (GTC ≈ 13 MB each); on a RAM disk efficiency is 0.77 at 16 and 0.48 at 32 workers for 360 samples, explained by a fixed start-up cost (≈ 2.5 s + 0.2 s per worker). Linear scaling for large batches is inferred from that model, not measured. | `docs/validation/P9.md`; measure a ≥ 5000-sample batch when one is at hand. |
 | K-024 | 2026-09-28 | GSE165845 (P8) | GSA-MD v1 chips have no public cluster file; the GSA v1 C1 EGT with the C2 build-38 BPM covers 99.996 % of bead addresses and gives median LogR deviation 0.246 (cluster mismatch, not noise). GSM5051309 (NA20362 rep 2) is a failed array (call rate 0.762, concordance 0.336 with its own replicates). 27 510 array records have no NYGC 30x record and are scored as hom-ref; 1444 of them are systematically called alt. | Recorded in `docs/validation/P8.md`; results reported with and without these. |