Interestingly, several groups have reported EDS‐like phenotypes caused by classical OI genes such as COL1A1. 40, 41 Variants contributing to the EDS‐like phenotypes in atypical OI patients encompass a mosaic in‐frame deletion, frame‐shift deletion, or missense mutation in COL1A1. It is suspected that these mutations generate a hypomorphic protein, as opposed to the dominant negative form identified in dominant OI diseases. This evidence concerns the gene COL1A1 and Ehlers-Danlos syndrome.