Von Hippel-Lindau syndrome (vHL) is a hereditary cancer syndrome that predisposes to developing tumours in multiple organs. Initiating tumour surveillance before tumours are likely to occur is critical for optimal patient outcomes. In our study, we found significantly earlier ages of tumour onset in children with vHL compared to their vHL parents, indicating vHL may exhibit genetic anticipation (where symptoms present at younger ages in subsequent generations). Unlike dyskeratosis congenita, another cancer syndrome, anticipation in vHL was not associated with telomere shortening. Our observations support modifying surveillance guidelines to account for earlier ages of onset in younger generations with vHL. (By Kalene van Engelen, http://jmg.bmj.com/content/early/2018/02/06/jmedgenet-2017-104882 )