tokens: In these patients , 18 pathogenic variants were found in 13 genes ( COL2A1 , MYH3 , COMP , MATN3 , CTSK , EBP , CLCN7 , COL1A2 , EXT1 , TGFBR1 , SMAD3 , FIG4 , and ARID1B ) , of which , four were novel variants .