Neurobehavioral profiles of children with neurofibromatosis 1 referred for learning disabilities are sex-specific.

We compared neurobehavioral profiles of 10 children with neurofibromatosis 1 (NF-1) referred for evaluation of learning disabilities (NF/LD) to those to learning disabled children without known genetic disease (LD), matched for age, sex, and estimated IQ. It was hypothesized that the NF/LD children would exhibit a neurobehavioral profile diagnostic of compromise of frontal/subcortical brain systems while those of the case controls would be heterogeneous. Records from a clinical data base were reviewed retrospectively for the neurological and neuropsychological components of an interdisciplinary learning disabilities evaluation. Neurological abnormalities were more frequent in the NF/LD group, involving gross and fine motor coordination, praxis, and megencephaly. As predicted, clinical neuropsychological diagnostic ratings and composite neurobehavioral observation scores were consistent with compromise of frontal systems in the NF/LD group. An unanticipated finding was that outcomes in the NF/LD group were sex dependent: Megencephaly was observed in females only; and the frontal/subcortical neurobehavioral profile was more consistently observed in females. Females with NF-1 with megencephaly may be at increased risk for a neurobehavioral syndrome contributing to LD that is consistent with compromise of frontal/subcortical brain systems.