Evidence-Calibrated Reanalysis of an Otosclerosis Locus Generates a Testable Myeloid State Hypothesis

Background: Otosclerosis is a focal disorder of otic capsule bone remodeling, but variant-to-cell-state mechanisms remain unresolved. Methods: We performed an entirely secondary hypothesis-generating analysis of otosclerosis GWAS, osteoclast cis-eQTL, epigenomic, pooled Micro-C, and human single-cell RNA-sequencing datasets. Results: At a data-rich chromosome 13 locus selected for cross-layer tractability rather than prospective genome-wide superiority, colocalization was compatible with a shared regional signal under the conventional prior but was strongly prior-sensitive and did not resolve COL4A2-AS2, COL4A2, or RAB20 as a unique effector transcript. Seven credible variants overlapped one mature osteoclast ATAC element, and merged osteoclast loop calls connected the risk/COL4A2-AS2 interval with RAB20; related PBMC contacts and the absence of donor-resolved matrices precluded an osteoclast-specific regulatory claim. In a separate 12-donor bone metastasis dataset lacking chr13 genotypes, RAB20 marked an AP1/CTNNB1-associated myeloid state, while a four-donor non-tumor femoral head dataset provided only directional cross-context prioritization of a CXCL8-CXCR2 candidate axis. A simplified comparison across all 27 reported GWAS loci showed that the chr13 locus was among loci with credible variants in mature osteoclast open chromatin but was not uniquely strongest across the examined annotations. Conclusions: No analyzed dataset jointly measured the risk haplotype and the RAB20-associated state, and no raw dataset sampled an otosclerosis lesion. Thus, the genetic/topological and transcriptomic observations remain separate evidence blocks that generate a falsifiable myeloid state hypothesis rather than establish a mechanistic or causal pathway.