Noonan syndrome (NS)-associated LZTR1 variants may be inherited in a dominant manner (caused by inheriting a mutated copy of the gene from one parent) or a recessive manner (caused by inheriting mutated copies of the same gene from both parents) and there is overlap between the type of mutation identified in people with NS or schwannomatosis, although schwannomas are not a feature of Noonan syndrome. NS is caused by disruption to a cell signalling pathway, called RAS-MAPK. Several other genes have been associated with the condition, including PTPN11, KRAS, SOS1, RAF1, SHOC2, NRAS, CBL, BRAF, MAP2K1, RIT1, RASA2 and SOS2.
Schwannomatosis-related LZTR1 mutations are inherited in a dominant manner (one mutated copy of the gene from on parent). However, not everyone who has an LZTR1 mutation that would be expected to cause schwannomatosis will actually develop tumours.
LZTR1