- Keratosis Follicularis Spinulosa Decalvans is caused by mutations in MBTPS2. Aten, E., Brasz, L.C., Bornholdt, D., Hooijkaas, I.B., Porteous, M.E., Sybert, V.P., Vermeer, M.H., Vossen, R.H., van der Wielen, M.J., Bakker, E., Breuning, M.H., Grzeschik, K.H., Oosterwijk, J.C., den Dunnen, J.T. Hum. Mutat. (2010)