What is the inheritance pattern of neurofibromatosis type 1? Penetrance?
In half of cases, the disease is inherited as an autosomal dominant condition. In the other 50% of cases the disease is due to a new mutation. There is variable expression but 100% penetrance by 5 years of age.
Very extensive features consistent with neurofibromatosis are demonstrated, involving all imaged regions. These are unchanged when compared to previous imaging.
The largest intraspinal neurofibroma is located in the lumbar spine, posterior to the vertebral body of L2 and L3, where the entire canal is filled, with associated bony remodelling. The thoracic canal is relatively uninvolved without significant distortion of the thoracic cord. The cervical canal is most stenosed at the level of C2/3 were bilateral neurofibromas distorting and compressing the cervical cord.
Bilaterally the brachial plexuses and lumbar plexuses and intercostal nerves are extensively involved with numerous other neurofibromas throughout the soft tissues.