NF1 and memory impairment: NF1, one of the RasGAPs encoding neurofibromin, is the causative gene of neurofibromatosis type I. Previous studies have reported learning disabilities in 30–65% of children with neurofibromatosis type I (North, 2000) and memory impairment in neurofibromatosis type I model mice (Costa et al., 2002).