Abstract: Objective　To investigate the clinical phenotype and molecular diagnosis of Noonan syndrome (NS) caused by mutations in SHOC2 gene. Methods　The clinical data and gene testing results of one child with NS were analyzed retrospectively. Results　This is an 8-month-old infant. Since birth, the boy had feeding and sleeping difficulties, irritability, and growth retardation. The boy had large head circumference, sparse, thin and yellow hair, broad and prominent forehead, flat nose, slightly wide eye distance, and slightly bilateral eye fissure outward tilt, no eyelid ptosis. Echocardiography showed patent foramen ovale, ventricular septum and left ventricular hypertrophy. A novel mutation (De novo) was found in the SHOC2 gene, heterozygous missense mutation c.4A>G, p.Ser2Gly His parents were normal genotypes. According to the clinical characteristics, relevant literature was reviewed. The clinical manifestation of sleep difficulty has not been reported in the NS patients with SHOC2 mutation. Conclusions　This is the first domestic reported NS case with SHOC2 mutation. The phenotype is consistent with the foreign reports. Sleep difficulty may be a new phenotype of NS with SHOC2 mutation.