NF1 and plexiform neurofibroma: Few clear correlations have been established other than a whole-NF1 deletion associated with severe clinical phenotypes, such as cognitive defects, body or facial dysmorphisms, an early onset of cutaneous neurofibromas10, 11, and a 3-bp in-frame deletion (c.2970_2972delAAT) linked to a relatively milder phenotype (with an absence of neurofibromas)12.