Causes of Neurocutaneous Syndromes in Children
Tuberous sclerosis (TS) is an autosomal dominant disorder. Autosomal means that both boys and girls are affected. Dominant means that only 1 copy of the gene is needed to have the condition. A parent with TD or the gene for TD has a 50% chance to pass the gene on to each child. Many children born with TS are the first cases in a family. This is because most cases of TS are caused by a new gene change (mutation), and are not inherited. But the parents of a child with TS may have very mild symptoms of the disorder. The parents are believed to have a slightly increased risk of having another child with TS.                                                                           

Neurofibromatosis Type 1 (NF1) occurs in about 1 in 3,000 to 4,000 babies in the U.S. NF1 is an autosomal dominant disorder. It’s caused by changes in a gene on chromosome 17. In 50% of cases, this is inherited from a parent with the disease.

Neurofibromatosis Type 2 (NF2) is less common. It affects about 1 in 25,000 babies in the U.S. The gene change that causes NF2 is on chromosome 22.

A parent with NF has a 50% chance of passing on the genetic mutation and disease to each child.  

NF may also be the result of a new gene change. From 3 in 10 to 1 in 2cases of NF are caused by a new mutation and not inherited. Boy and girls are equally affected.

Schwannomatosis is a form of NF. It is rare, and only 3 in 20 cases are inherited. There are 2 genetic forms of schwannomatosis:

Schwannomatosis 1. This is caused by mutations in a gene called SWNTS1. This condition is also known as congenital cutaneous neurilemmomatosis.

Scwannomatosis 2. This condition starts in adulthood. It causes schwannomas to grow throughout the body. But it has no other symptoms.