It is caused by mutations in the NF1 gene, which encodes neurofibromin, a protein involved in the Ras signalling pathway.
Patients have tumours of neural origin and many have learning difficulties.
Previous attempts to knock out the NF1 gene have been unsuccessful because the mutant mice die as embryos. Now, a team of researchers led by Luis Parada of the University of Texas Southwestern Medical Center have generated mice in which an NF1 gene mutation is triggered only in neuronal cells. Reporting in the 1 April Genes and Development , Zhu et al inserted loxP sites flanking exons 31 and 32 of the mouse NF1 gene. The NF1 mutant mice had severe learning defects but did not develop tumours. This suggests that the loss of NF1 in mature, differentiated neurons might not be sufficient to induce tumour development.