- Splicing mutations of 54-bp exons in the COL11A1 gene cause Marshall syndrome, but other mutations cause overlapping Marshall/Stickler phenotypes. Annunen, S., Körkkö, J., Czarny, M., Warman, M.L., Brunner, H.G., Kääriäinen, H., Mulliken, J.B., Tranebjaerg, L., Brooks, D.G., Cox, G.F., Cruysberg, J.R., Curtis, M.A., Davenport, S.L., Friedrich, C.A., Kaitila, I., Krawczynski, M.R., Latos-Bielenska, A., Mukai, S., Olsen, B.R., Shinno, N., Somer, M., Vikkula, M., Zlotogora, J., Prockop, D.J., Ala-Kokko, L. Am. J. Hum. Genet. (1999)