Corrigendum

The authors would like to apologise for the incorrect spelling of two of the authors' names. In the original article published online on the 27th March 2018, Peter Humaidan was listed as 'Peter Huamidan' and Christophe Blockeel was listed as 'Cristophe Blockeel'. The electronic version of this article has been updated at https:// doi.org/10.1093/humrep/dey061. The authors would like to assure readers that this does not affect any content of the letter.