Paternally Inherited Noonan Syndrome Caused by a PTPN11 Variant May Exhibit Mild Symptoms: A Case Report and Literature Review.

p.Arg498Trp variant, including our cases, may exhibit relatively lower frequencies of abnormal features and mild symptoms. This could be ascribed to potential gene-gene interactions, gene-environment interactions, the gender and phenotype of the transmitting parent, or ethnic differences that influence the clinical phenotype.