Table 6 compares the features of recessive SS with dominant SS. In cases of clinically likely Stickler Syndrome but without COL2A1 or COL11A1 pathogenic variants detected, recessive SS must be considered, particularly in de novo cases and, again, highlighting the importance of the functional analysis of apparently benign variants inherited in tandem with known pathogenic variants on the other allele. This evidence concerns the gene COL2A1 and synovial sarcoma.