• The oITspring of an afTected individual have a 50% risk of inheriting the altered NF1 gene, but thc discase manifestations are extrcmcly yariable, even within a fam iły. Penetrance is almost 100%, so a child who inhcrits an NF1 mutation will almost certainly develop features ofNFl.
* Prenatal diagnosis is often possible but is of limited prognostic value.