目的 总结儿童肥厚型心肌病（HCM）中Noonan综合征的基因变异与临床特征。方法 对123例儿童肥厚型心肌病先证者进行96个遗传性心肌病相关基因的二代测序及生物信息学分析，确定变异位点;筛选出11例Noonan综合征患儿，收集其临床资料及超声心动图结果。结果 11例患儿均因心肌肥厚就诊，男5例、女6例，肥厚型心肌病诊断中位年龄2岁7个月（5个月~10岁），Noonan综合征诊断中位年龄6岁9个月（7个月~16岁）。11例患儿中10例为3号染色体RAF1基因型，1例为12号染色体PTPN11基因型;7例为新发变异，其中1例RAF1基因患儿检测出同时携带与肥厚型心肌病相关的变异基因MYBPC3。11例患儿中9例具有典型Noonan综合征面部特征。11例患儿均为肥厚型心肌病，9例为梗阻性肥厚型心肌病，合并右室流出道梗阻2例，合并先天性心脏病7例。结论 以肥厚型心肌病为表型的儿童Noonan综合征多为RFA1基因型，易发生左心室流出道梗阻且多合并先天性心脏病。

Objective To retrospectively summarize the genetic variants and clinical characteristics of Noonan syndrome in children with hypertrophic cardiomyopathy (HCM). Methods A total of 123 children with HCM were enrolled in this study. Second generation sequencing and bioinformatic analysis of 96 genes associated with hypertrophic cardiomyopathy were performed in 123 probands. Eleven patients with diagnosed with Noonan syndrome, and their clinical data and echocardiographic findings were collected. Results The median age of diagnosis of HCM was 2 years and 7 months (5 months to 10 years), and the median age of diagnosis of Noonan syndrome was 6 years and 9 months (7 months to 16 years). 10 of 11 children had variants in RAF1 gene on chromosome 3, one had variant in PTPN11 gene on chromosome 12, and 7 had other novel variants. One of the patients with RAF1 was also found carrying variant in MYBPC3 which is associated with HCM. Nine out of 11 patients with HCM had typical facial features of Noonan syndrome. All 11 children had hypertrophic cardiomyopathy, 9 with obstructive hypertrophic cardiomyopathy, 2 with right ventricular outflow tract obstruction, and 7 with congenital heart disease. Conclusion RFA1 mutation is commonly seen in children with HCM in Noonan syndrome. Those patients carried with RFA1 mutation are more likely to have left ventricular outflow track obstruction and congenital heart diseases.