Schwannomatosis

Schwannomatosis is a broad name for several genetic conditions that cause tumors to form on nerves in your body. These tumors are known as schwannomas. They develop from insulating nerve cells called Schwann cells in your peripheral nervous system (nerve roots, nerves and nerve-muscle junctions). Schwannomatosis usually leads to chronic pain that typically starts in early adulthood.

Schwannomatosis is a type of neurofibromatosis. This is a group of conditions that cause tumors to grow in your nervous system.

What are the types of schwannomatosis?

There are six types of schwannomatosis identified by the genetic variant that causes each one:

• NF2-related schwannomatosis (formerly known as neurofibromatosis type 2).
• SMARCB1-related schwannomatosis.
• LZTR1-related schwannomatosis.
• 22q-related schwannomatosis.
• Schwannomatosis not otherwise specified (NOS).
• Schwannomatosis not elsewhere classified (NEC).

How rare is schwannomatosis?

Schwannomatosis is the rarest type of neurofibromatosis. The exact rate of occurrence varies. Studies estimate that NF2-related schwannomatosis may affect an estimated 1 in 30,000 people and all remaining types affect 1 in 70,000 people.

Schwannomatosis only affects a small number of people who develop schwannoma tumors. It’s more common to have a single schwannoma tumor than multiple schwannomas, as with schwannomatosis.