SOS1 and Noonan syndrome: Other known gene variations that lead to NS are NS3 (609942), KRAS (190070); NS4 (610733), SOS1 (182530); NS5 (611553), RAF1 (164760); NS6 (613224), NRAS (164790); NS7 (613706), BRAF (164757); NS8 (615355), RIT1 (609591); NS9 (616559), SOS2 (601247); NS10 (616564), LZTR1 (600574); NS11 (618499), MRAS (608435), NS12 (618624), RRAS2 (600098), NS13 (619087) and MAPK1 (176948), while the autosomal recessive form of Noonan syndrome is caused by NS2 (605275), LZTR1 (600574), NS14 (619745) and SPRED2 (609292) [5,6,7].