COL9A2 and connective tissue disorder: These three genes are considered to cause Stickler’s syndrome, a connective tissue disorder caused by mutations in collagen genes, which can be inherited as an autosomal dominant disorder if COL2A1, COL11A1 or COL11A2 (OMIM:120290) are affected, or as autosomal recessive if COL9A1, COL9A2 (OMIM:120260) and COL9A3 (OMIM:120270) are affected [55].