Among the above described genes, EXT2 is related to SD, the mutation of which leads to multiple exostoses type II (EXT2; #133701) (Fusco et al. 2019); while ALX4 mutation leads to parietal foramina‐2 (PFM2; #609597) (Altunoglu et al. 2014). This evidence concerns the gene EXT2 and exostoses, multiple, type 2.