78cdae7249c8609dcbc743e996ea7e5eec33d75a
max
  Mon Aug 17 08:15:39 2026 -0700
lrSv: fix off-by-one anchor base in deletion coordinates across converters, refs #38099

VCF/pangenome deletions carry a non-deleted anchor (padding) base at POS.
Several lrSv converters set chromStart = pos-1, which includes that anchor, so
each deletion was 1 bp too wide on the left and svLen was 1 too big. Callsets
handled this inconsistently, so the same deletion appeared at offset coordinates
and failed to merge in lrSvAll.

For deletions only (INS/INV/CPX unchanged), advance chromStart past the anchor
so the interval covers exactly the deleted bases (svLen == |SVLEN|). Verified
against the hg38 reference: the old left base is present in both REF and ALT
(i.e. retained by the sample), so it should not be inside the deletion.

Fixed 11 converters: lrSv1kLin1218VcfToBed, lrSv1kgOntVcfToBed,
lrSvGustafsonVcfToBed, lrSvGa4kSvVcfToBed, lrSvDecodeVcfToBed,
lrSvAou1kCsvToBed, lrSvColorsDbSvVcfToBed, lrSvCardBbToBed, lrSvAprVcfToBed,
lrSvCpc1VcfToBed, lrSvVcfToBed (generic, used by han945).

Left unchanged, verified already anchor-correct: hgsvc3 and hgsvc2 (0-based
source), hprc2v21 (Ro converter prefix-trims), noyvert/tommoJp (POS is the
first deleted base), chirmade101 (1-based-closed source).

Rebuilt all affected bigBeds (hg38 + hs1 where present) and the lrSvAll merge:
3,111,026 -> 2,963,093 rows as ~148k duplicate deletions now merge.

diff --git src/hg/makeDb/scripts/lrSv/lrSv1kLin1218VcfToBed.py src/hg/makeDb/scripts/lrSv/lrSv1kLin1218VcfToBed.py
index 631841cb88b..d58656e4dcb 100644
--- src/hg/makeDb/scripts/lrSv/lrSv1kLin1218VcfToBed.py
+++ src/hg/makeDb/scripts/lrSv/lrSv1kLin1218VcfToBed.py
@@ -64,30 +64,37 @@
         for line in fIn:
             if line.startswith("#"):
                 continue
 
             fields = line.rstrip("\n").split("\t")
             chrom = fields[0]
             pos = int(fields[1])
             info = parseInfo(fields[7])
 
             svType = normalizeSvType(info.get("SVTYPE", "."))
             svLenRaw = toInt(info.get("SVLEN", "0"))
             end = toInt(info.get("END", str(pos)))
 
             chromStart = pos - 1
             chromEnd = end
+            # VCF POS is the anchor base (present in both REF and ALT); it is not
+            # part of a deletion, so the deleted region starts one base to the
+            # right. Drop the anchor from the left of DEL intervals so svLen ==
+            # |SVLEN| and coordinates match anchor-excluded callsets (e.g.
+            # HGSVC3). INS keeps the anchor-based position.
+            if svType == "DEL":
+                chromStart += 1
             if chromEnd <= chromStart:
                 chromEnd = chromStart + 1
 
             svLen = chromEnd - chromStart
             insLen = abs(svLenRaw) if svType in ("INS", "MEI") else 0
 
             ac = toInt(info.get("AC", "0"))
             an = toInt(info.get("AN", "0"))
             af = toFloat(info.get("AF", "0"))
             afAfr = toFloat(info.get("AF_AFR", "0"))
             afAmr = toFloat(info.get("AF_AMR", "0"))
             afEas = toFloat(info.get("AF_EAS", "0"))
             afEur = toFloat(info.get("AF_EUR", "0"))
             afSas = toFloat(info.get("AF_SAS", "0"))
             ns = toInt(info.get("NS", "0"))