Noonan syndrome (NS) can affect many different parts of the body and can be inherited in families. It found in 1 in 1,000-2,500 people and LZTR1 mutations account for up to 8% of these. NS affects facial features, such as a large head, widely spaced eyes with drooping eyelids, and low-set ears. It can also cause sunken or protruding chest, and/or curvature of the spine, and learning difficulties.
Schwannomatosis can cause benign, but painful tumours in the brain and nervous system. Mutations in the LZTR1 gene are inherited in a dominant manner and are thought to cause schwannomatosis in about 1 in 421,050 people.