PTPN11 and Noonan syndrome: Figure 1 shows an electrocardiogram of a patient with Noonan syndrome. Previous reports indicated that these typical electrocardiogram findings in Noonan syndrome were not associated with PTPN11 mutations and were not related to congenital heart disease [8,9]. However, the exact mechanism underlying the typical electrocardiographic features of Noonan syndrome is not well understood [7].