Optic nerve changes in PTPN11-related Noonan syndrome.

Characteristic features of Noonan syndrome include dysmorphic facies, short stature, and congenital cardiac defects. Pathogenic variants in PTPN11 are one of the common causes and may result in optic nerve head anomalies. We describe the optic nerve findings in two families with Noonan syndrome due to pathogenic variants in PTPN11. Optic nerve anomalies, including an enlarged cup/disc ratio, are a feature of Noonan syndrome due to pathogenic variants in PTPN11. This optic nerve anomaly could potentially lead to the misdiagnosis of glaucoma. PTPN11 is important for functional fibroblast growth factor signaling, which, if interrupted, may lead to optic nerve dysgenesis and ocular coloboma.