COL12A1 and Stickler syndrome: By contrast, Stickler syndrome has the most collagens (six) linked to this syndrome (COL2A1, COL9A1, COL9A2, COL9A3, COL11A1, and COL11A2; Supplementary Table S6), followed by Ullrich congenital muscular dystrophy, with four collagens associated (COL6A1, COL6A2, COL6A3, and COL12A1; Supplementary Table S6).