PTPN11 and Noonan syndrome: The Src homology region 2 domain-containing phosphatase-2 (SHP2) encoded by PTPN11, is a non-receptor protein tyrosine phosphatases (PTPs) required for MAPK signaling pathway.365–367 Germline heterozygous mutations in PTPN11 gene are closely associated to various diseases, Noonan syndrome (NS), and Noonan syndrome with multiple lentigines (NS-ML).