• The risk to the sibs of the proband depends upon the status of the pa ren U. If a pa ren t is aftected, the risk to the sibs is 50%.
* If ncither psi rent uf an indisidual with NF1 mccts the dinical diagnostic critcria for NF1 after carefu! mcdical history, physical ciamination, and ophthalmological ciamination, the risk to the sibs of the afTected individual of having NF1 is Iow. łloweser, gcrmlinc mosaicism for an NFlmutation bas bccn dcmonstratcd in an apparently nonnal man w ho had rwo chiłdrcn with typical NFl'
Offsnriną of a proband. Each chi Id has a 50% ćhance uf inneriting the mutant gcnc.