NF2-related-schwannomatosis is characterised by the development of benign tumours of nerve sheaths (schwannomas) and lining of the brain (meningiomas). Around 50—60% of affected people are the first in their family and half of these have genetic faults that change an amino acid to an instruction to stop making protein (nonsense). Although there are 60 positions in the NF2 code where nonsense variants have occurred, only six, all at ‘C’ letters that change CGA to TGA, account for half of all nonsense variations. These are far more common in NF2 than in APC which causes a similar tumour condition. (By Prof. Evans Gareth, https://jmg.bmj.com/content/early/2023/01/03/jmg-2022-108960 )