- Tumor development in the Beckwith-Wiedemann syndrome is associated with a variety of constitutional molecular 11p15 alterations including imprinting defects of KCNQ1OT1. Weksberg, R., Nishikawa, J., Caluseriu, O., Fei, Y.L., Shuman, C., Wei, C., Steele, L., Cameron, J., Smith, A., Ambus, I., Li, M., Ray, P.N., Sadowski, P., Squire, J. Hum. Mol. Genet. (2001)