- Autosomal dominant stapes ankylosis with broad thumbs and toes, hyperopia, and skeletal anomalies is caused by heterozygous nonsense and frameshift mutations in NOG, the gene encoding noggin. Brown, D.J., Kim, T.B., Petty, E.M., Downs, C.A., Martin, D.M., Strouse, P.J., Moroi, S.E., Milunsky, J.M., Lesperance, M.M. Am. J. Hum. Genet. (2002)