PTPN11 and Noonan syndrome: Missense mutations of PTPN11 are the cause of 50% of cases of Noonan syndrome (NS; OMIM 163950) and 95% of cases of LEOPARD syndrome (LS; OMIM 151100) (Tartaglia et al., 2001; Digilio et al., 2002; Legius et al., 2002; Tartaglia et al., 2002; Zenker et al., 2004; Jongmans et al., 2005; Tartaglia et al., 2010; Martinez-Quintana and Rodriguez-González, 2012).