ABSTRACT
@#【Objective】Through summarizing the clinical manifestations and gene mutations of 5 types of RASopathies in childhood including Neurofibromatosis type1（NF1），Noonan syndrome（NS），Noonan syndrome with multiple lentigines（NSML），Costello syndrome（CS）and cardio-facio-cutaneous syndrome（CFC）and analyzing their commonalities and characteristics，to deepen the clinician′s understanding of the RASopathies and improve the domestic doctors′ diagnosis and treatment level of RASopathies.【Methods】The clinical data and gene mutation types of 11 patients of RASopathies who were diagnosed in Sun Yat- Sen Memorial Hospital from January 2015 to May 2018 were retrospectively analyzed. 【Results】The age of onset ranged from 6 months to 12 years and the main clinical manifestations of 11 patients included： short stature，craniofacial features，congenital heart defect，café-au-lait macules，developmental delay，thrombocytopenia， seizures and dystonia，cryptorchidism，etc. Five gene mutations were detected including NF1 gene，PTPN11 gene， RAF1 gene ，BRAF gene and HRAS gene.【Conclusions】The RASopathies are a clinically defined group of medical genetic syndromes caused by germline mutations in genes that encode components or regulators of the Ras/MAPK pathway. The RAS/MAPK pathway plays an important role in regulating growth development，promoting cell proliferation，differentiation，metabolism，and signal transduction of various hormones. Therefore，they share many overlapping characteristics，including craniofacial features，growth retardation，cardiac malformations，cutaneous and musculoskeletal abnormalities，neurocognitive impairment and tumor susceptibility. However ，each RASopathy exhibits different degree phenotypes because of mutations at different points in the pathway. In addition ，tumor susceptibility is one of the typical clinical features of RASopathies. Therefore，tumor monitoring is one of the most important contents in the follow-up process.