Types of neurofibromatosis and related disorders

Legius syndrome is also called neurofibromatosis type 1-like syndrome because its symptoms are similar to NF1. Individuals with Legius syndrome have skin differences including brown birthmarks (cafe-au-lait spots) and freckling, as well as mild learning problems and a larger head. Other NF1 symptoms, such as tumors, are typically not seen in Legius syndrome.

Legius syndrome can be inherited from a parent or result from a new genetic change, so the individual may be the first person in the family to have the condition. If a person has Legius syndrome, there is a 50% chance for each of their children to also have Legius syndrome. This is called autosomal dominant inheritance.

LZTR1- and SMARCB1-related schwannomatosis are characterized by noncancerous growths or tumors, called schwannomas. The most common early signs in affected individuals are pain or physical problems related to nerve dysfunction.

Schwannomatosis can be inherited from a parent; however, some people have schwannomatosis as a result of a new genetic change, so they will have no family history of the condition. If an individual has schwannomatosis, there is a 50% chance for each of their children to inherit the condition.

Neurofibromatosis type 1 (NF1)
The most recognized signs of NF1 are brown-colored birthmarks, called cafe-au-lait spots. Individuals with NF1 typically have 6 or more of these spots, generally larger than 5 millimeters in childhood and larger than 15 millimeters after puberty. Some babies are born with cafe-au-lait spots, but most develop them within the first few years of life. Other symptoms of NF1 vary, even within the same family, and may be mild or more complex. Individuals with NF1 develop growths, or tumors, and the most common types are called neurofibromas. These typically are noncancerous growths but may cause medical, functional or cosmetic concerns. Individuals with NF1 sometimes have eye problems, so an eye exam is important. About 50% of individuals with NF1 have a learning disability. Intellectual disabilities are uncommon.

NF1 can be inherited from a parent; however, about 50% of people with NF1 have the condition as a result of a new genetic change, so they will have no family history of NF1. If an individual has NF1, there is a 50% chance for each of their children to also have NF1. This is called autosomal dominant inheritance.

NF2-related schwannomatosis (formerly neurofibromatosis type 2) (NF2) is a condition that causes different types of noncancerous growths or tumors. These tumors most often appear during late childhood or early adulthood, but in some cases, may be recognized earlier. NF2 tumors are most commonly located along the hearing and balance nerves. These tumors, called vestibular schwannomas, lead to hearing loss and may lead to deafness. NF2-related tumors may also appear in other areas of the body. Individuals with NF2 may have eye problems, so an eye exam is important.

NF2 can be inherited from a parent; however, about 50% of people with NF2 have the condition because of a new genetic change, so they will have no family history of NF2. If an individual has NF2, there is a 50% chance for each of their children to also have NF2. This is called autosomal dominant inheritance.

Learn more about the Neurofibromatosis and RASophathy program at Children’s Wisconsin.