684ad73a17eebb717fba52f0aa25f3d9d7adb2de
max
  Thu Sep 3 12:03:37 2026 -0700
New Imprinting track collection on hg38, first subtrack is MethBase2 ASM

Adds the "Imprinting" superTrack to the Regulation group and its first
subtrack, the allele-specific methylation summary from the MethBase2 hub
(http://smithlab.usc.edu/trackdata/methylation/hub.txt). The bigWig gives,
for each of 29,401,795 CpG sites, the fraction of MethBase2 human methylomes
in which the site fell inside an allelically methylated region called by
dnmtools amrfinder. Taken from upstream unchanged.

Alpha only for now, refs #37599

diff --git src/hg/makeDb/trackDb/human/hg38/imprinting.html src/hg/makeDb/trackDb/human/hg38/imprinting.html
new file mode 100644
index 00000000000..24323e1c11a
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+++ src/hg/makeDb/trackDb/human/hg38/imprinting.html
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+<h2>Description</h2>
+
+<p>
+Genomic imprinting is the small set of exceptions to the rule that both copies
+of a gene are expressed. At an imprinted locus only the maternal or only the
+paternal copy is active, and which one it is was decided in the germline of the
+parent that passed it on. The instruction is carried by DNA methylation: one
+allele has methylated CpG sites and the other does not, so the two copies look
+different to the transcription machinery even though their sequence is the same.
+The regions that hold this asymmetry are called imprinting control regions, and
+a single one can govern the expression of a whole cluster of neighboring genes.
+Losing or gaining methylation at these regions is the cause of several
+developmental syndromes.
+</p>
+
+<p>
+This collection brings together annotations that mark imprinted loci and the
+allele-specific methylation that defines them.
+</p>
+
+<h2>Subtracks</h2>
+
+<ul>
+<li>
+<a href="hgTrackUi?g=methBaseAsm">MethBase2 ASM</a> &mdash; for every CpG site,
+the fraction of MethBase2 human methylomes in which the site was part of an
+allelically methylated region. Peaks mark candidate imprinting control regions.
+</li>
+</ul>
+
+<h2>Data Access</h2>
+
+<p>
+Each subtrack has its own description page with the details on how the data was
+made and how to download and intersect the annotations. Use the links above.
+</p>