Most genes linked to inherited diseases follow either a dominant or recessive pattern, but some genes can cause disease through both modes. This study investigated these unusual “dual-inheritance” genes. The researchers compiled a list of 562 such genes and identified key features that set them apart, and other features that were intermediate between the two classical groups. The researchers also found new genes that might belong to this category, which had previously been classified as dominant only. Understanding these genes is important because genetic variants that don’t fit expected inheritance patterns can be missed or misinterpreted. This work could improve genetic diagnoses and deepen our understanding of how inherited diseases develop. (By Dr Tamar Harel, https://jmg.bmj.com/content/early/2025/08/06/jmg-2025-110872 )