Verified Memory for Knowledge Reuse in Variant-to-Gene Agents

Agents that prioritise causal genes at genome-wide association (GWAS) loci are typically stateless: every locus is re-analysed from scratch, even when the same gene–trait relationship was already established in an earlier study. We present EviMem+CAVE, a memory layer for such agents that stores verified gene–trait claims in a four-state contract (CAVE) and retrieves prior loci by a numeric Evidence Fingerprint (EviMem). On a frozen benchmark of 844 loci (296 held-out test loci), the memory short-circuits 31.7% of within-ancestry test loci and 79.1% of cross-ancestry replication loci, answering them without an LLM call (top-1 precision 0.925 and 0.977), and on the within-ancestry test loci raises GPT-5.2 top-1 accuracy over the same agent without memory by +0.118 (95% CI +0.077 to +0.159). A mechanistic decomposition shows that the gain comes from verified reuse of recurrent gene–trait knowledge through the CAVE store rather than from fingerprint similarity, and that on novel gene–trait pairs we detect no improvement. We also show that a supervised baseline’s apparent lead is an artefact of how gold genes are inserted into candidate sets, and we report the evaluation protocol under which reuse can be measured separately from such artefacts