The authors have investigated the deleterious impact of interlocus gene conversion (IGC) — that is, non-reciprocal recombination between paralogous sequences — in inherited human disease. A genome-wide computational approach carried out on >60,000 known disease mutations in >3,000 genes showed that ~1% of these genes contained pathological mutations resulting from ICG. Thousands of putatively deleterious mutations were also detected, which is unsurprising, given the high number of paralogous sequences that can act as donors in ICG events.