weighted sequence of a magnetic resonance imaging examination of the brain. These UBOs are typically found in the Cerebral peduncle, pons, midbrain, globus pallidus, thalamus, and optic radiations. Their exact identity remains a bit of a mystery since they disappear over time (usually, by age 16), and they are not typically biopsied or resected. They may represent a focally degenerative bit of myelin. Dural ectasia Within the CNS, NF-1 manifests as a weakness of the dura, which is the tough covering of the brain and spine. Weakness of the dura leads to focal enlargement due to chronic exposure to the pressures of CSF pulsation, and typically presents as paraesthesia or loss of motor or sensory function. It has been shown that dural ectasia occur near plexiform neurofibromas which may be infiltrative leading to weakening of the dura. Acetazolamide has shown promise as a treatment for this condition, and in very few cases do dural ectasia require surgery. Mental disorder Children and adults with NF-1 can experience social problems, attention problems, social anxiety, depression, withdrawal, thought problems, somatic complaints, learning disabilities and aggressive behavior. Treatments include psychotherapy, antidepressants and cognitive behavioral therapy. Puberty and height Children diagnosed with NF-1 may experience delayed or precocious puberty. Recent studies have correlated precocious puberty in individuals with NF-1 with the presence of optic pathway tumors. Furthermore, the heights of children affected by NF-1 have been shown to increase normally until puberty, after which increases in height lessen when compared to healthy counterparts. This eventually causes a shorter stature than expected in individuals with NF-1. Cancer Cancer can arise in the form of malignant peripheral nerve sheath tumor resulting from malignant degeneration of a plexiform neurofibroma. Frequency. A plexiform neurofibroma has a lifetime risk of 8–12% of transformation into a malignant tumor. Diagnosis. MRI. Treatment. Surgery (primary), radiation therapy. Mortality. Malignant nerve sheath tumor was the main cause of death (60%) in a study of 1895 patients with NF-1 from France in the time period 1980–2006 indicated excess mortality in NF-1 patients compared to the general population. The cause of death was available for 58 (86.6%) patients. The study found excess mortality occurred among patients aged 10 to 40 years. Significant excess mortality was found in both males and females. Cause Neurofibromin 1 gene NF-1 is a microdeletion syndrome caused by a mutation of a gene located on chromosomal segment 17q11.2 on the long arm