PROKR2 and Noonan syndrome: Syndromes with the highest number of associated genes are Kallmann (ANOS1, CHD7, DUSP6, FEZF1, FGF17, FGF8, FGFR1, FLRT3, FSHB, GNRH1, GNRHR, HS6ST1, IL17RD, KISS1, KISS1R, LHB, NDNF, NSMF, PROK2, PROKR2, SEMA3A, SPRY4, TAC3, TACR3, WDR11) and Noonan syndrome (PTPN11, KRAS, SOS1, RAF1, NRAS, BRAF, LZTR1, SOS2, and RIT1).