For example, LEOPARD syndrome and Noonan syndrome, belonging to RASopathies, share several phenotypic features: characteristic facies, congenital heart defects, delayed development, and cryptorchidism for which the molecular causes are heterozygous mutations in various exons of RAF1 and PTPN11 (26, 40, 49). Here, PTPN11 is linked to Noonan syndrome.