Gene-related Chinese NS facial features were described using artificial intelligence (AI).NGS identified pathogenic variants in 103 Chinese patients in eight NS-related genes: PTPN11 (48.5%), SOS1 (12.6%), SHOC2 (11.7%), KRAS (9.71%), RAF1 (7.77%), RIT1 (6.8%), CBL (0.97%), NRAS (0.97%), and LZTR1 (0.97%).
Affected individuals exhibited features fitting Noonan syndrome, and the observed germline variants differed from the typical oncogenic NRAS changes occurring as somatic events in tumours.
While the underlying pathophysiologic mechanism of PIG is unclear, we suggest that the mitogen-activated protein kinase signal transduction pathway members (PTPN11, KRAS, SOS1, RAF1, SHOC2, NRAS) involved in cellular growth factor signaling, which are affected in NS, can provide clues.
RASopathies (Noonan syndrome (NS) and Noonan-related syndromes) are neurodevelopmental syndromes resulting from germline mutations in genes that participate in the rat sarcoma/mitogen-activated protein kinases (RAS/MAPK) pathway (PTPN11, SOS1, RAF, KRAS or NRAS, and SHOC2).
We report on the mutational analysis of NRAS in a cohort of 125 French patients with NS and no known mutation for PTPN11, KRAS, SOS1, MEK1, MEK2, RAF1, BRAF, and SHOC2.
In conclusion, mutations in NRAS from individuals with Noonan syndrome activated N-Ras signaling and induced developmental defects in zebrafish embryos, indicating that activating mutations in NRAS cause Noonan syndrome.
In conclusion, mutations in NRAS from individuals with Noonan syndrome activated N-Ras signaling and induced developmental defects in zebrafish embryos, indicating that activating mutations in NRAS cause Noonan syndrome.
In conclusion, mutations in NRAS from individuals with Noonan syndrome activated N-Ras signaling and induced developmental defects in zebrafish embryos, indicating that activating mutations in NRAS cause Noonan syndrome.
Germline mutations in genes encoding small GTPases of the RAS family (KRAS and NRAS), modulators of RAS function (PTPN11, SOS1 and SHOC2) or downstream signal transducers (RAF1) are causative for NS.