The symptoms related to NF1 and NF2 are different.
People with NF1 may have some of the following symptoms:
- noncancerous tumours under the skin (or deeper within the body)
- brown patches in the iris (coloured part of the eye) called Lisch nodules
- bowed legs, short stature, or bone abnormalities including scoliosis (an abnormal side-to-side curve in the spine)
- freckles in the groin or underarm area
- growth of a tumour on the optic nerve (an optic glioma)
- light brown flat skin marks called "café au lait" spots
Because it affects the nervous system, NF1 may cause learning disabilities, speech problems, and delays in an individual's development. Seizures, eye tumours, and high blood pressure may also affect people with this condition. Rarely, the tumours may become malignant (cancerous). In some cases, tumours may also affect organs within the body.
People with NF2 develop tumours that appear on the nerve that connects the ear to the brain. These tumours are also called "schwannomas." Because of their association with the ear, tumours on this nerve may cause hearing difficulties. Other complications related to the ear may include dizziness, ringing in the ears (tinnitus), and balance problems. The pressure from the tumours on other nerves may also cause headaches or numbness of the face or weakened facial muscles.
People who have NF2 may also develop tumours in other body areas, such as the brain and spinal cord. Unlike NF1, skin discoloration and freckles are few or nonexistent in people with NF2. Cataracts can develop early in life, which may cause vision difficulties or blindness.