- TCOF1 gene encodes a putative nucleolar phosphoprotein that exhibits mutations in Treacher Collins Syndrome throughout its coding region. Wise, C.A., Chiang, L.C., Paznekas, W.A., Sharma, M., Musy, M.M., Ashley, J.A., Lovett, M., Jabs, E.W. Proc. Natl. Acad. Sci. U.S.A. (1997)