NF1 and plexiform neurofibroma: Patients with NF1 caused by large deletions such as whole-gene deletions (termed NF1 microdeletions) present with somatic overgrowth, dysmorphism, an earlier and heavier burden of cutaneous and plexiform neurofibromas, an increased risk of malignant peripheral nerve sheath tumour development, and more severe neurocognitive delay compared to individuals with single nucleotide variants (Cnossen et al., 1997; Mautner et al., 2010).