Types of neurofibromatosis and related disorders

Legius syndrome is a newly identified condition. Legius syndrome also is called a neurofibromatosis 1-like syndrome because its symptoms are similar to NF1. Individuals with Legius syndrome have skin problems including brown birthmarks, called cafe-au-lait spots, and freckling, as well as mild learning problems and a larger head. Other NF1 symptoms, such as tumors, typically are not seen in this condition. If an individual has Legius syndrome, there is a 50 percent chance of having a child with Legius syndrome. This is called autosomal dominant inheritance.

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 percent of individuals with NF1 have a learning disability. Intellectual disabilities are uncommon.

Although NF1 and NF2 share a name, they are separate conditions related to different genetic causes. NF1 can be inherited from a parent, however, about 50 percent 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 percent chance of having a child with NF1. This is called autosomal dominant inheritance.

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, called vestibular schwannomas. These tumors lead to hearing loss and may lead to deafness. NF2-related tumors also may appear in other areas of the body. Individuals with NF2 may have eye problems, so an eye exam is important.

Although NF1 and NF2 share a name, they are separate conditions related to different genetic causes. NF2 can be inherited from a parent, however, many people with NF2 have the condition as a result of a new genetic change, so they will have no family history of NF2. If an individual has NF2, there is a 50 percent chance of having a child with NF2. This is called autosomal dominant inheritance.

Schwannomatosis is a condition that is related to many noncancerous growths or tumors, called schwannomas. The most common early signs are pain or physical problems related to nerve dysfunction. Although there is some relationship between schwannomatosis and neurofibromatosis type2, the main difference is that individuals with schwannomatosis do not have tumors along their hearing and balance nerves. Schwannomatosis can be inherited from a parent, however some people with schwannomatosis have the condition as a result of a new genetic change, so they will have no family history of the disease. If an individual has schwannomatosis, there is a 50 percent chance of having a child with it. This is called autosomal dominant inheritance.

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