Human Molecular Genetics14, R19–R26 (2005)

The authors would like to apologise for the following error that appeared in this paper. On page R22, in the section entitled ‘TOO MUCH OF A GOOD THING’, second paragraph, first sentence, they incorrectly stated the following ‘The other group developed a mouse model in which MeCP2(308/Y) mice were made transgenic for the human MECP2 gene’.

In fact this mouse model was developed in wild-type mice, so this sentence should read

‘The other group developed a mouse model in which mice were made transgenic for the human MECP2 gene’.

This correction does not alter the conclusions of this review in any way.