A series of 44 unrelated patients in whom COL2A1 screening demonstrated normal results but whose phenotype was nevertheless highly suggestive of either Stickler syndrome (with ocular involvement) or Marshall syndrome were investigated for mutations in the COL11A1 gene.
Several mutations causing Stickler syndrome have been found in the COL2A1 gene, and one mutation causing Stickler syndrome and one causing Marshall syndrome have been detected in the COL11A1 gene.
A family with Stickler syndrome type 2 has a mutation in the COL11A1 gene resulting in the substitution of glycine 97 by valine in alpha 1 (XI) collagen.