Why it is difficult to distinguish the Silver-Russell syndrome (SRS) and 3M syndrome in clinical practice

Abstract

Background: To analyze why 3M syndrome can be regarded as a SRS-like syndrome by examining the patients with 3M syndrome and research the connection between 3M syndrome and SRS.Methods: The term “3M syndrome” was retrieved by Web of Science and the 3M patients were screened by NH-CSS to determine whether it was consist with the diagnosis of clinical SRS, and to analyze the relationship between the two diseases by exploring literature.Results: ① Among patients with 3M syndrome, 60/70 (83%) were in accordance with clinical SRS, and the coincidence rates of CUL7, OBSL1, CCDC8 gene mutations were: 30 (42%), 17 (24%) and 4 (6%) respectively; ② The phenotypes of 3M syndrome confirmed as clinical SRS were SGA (90%), short stature (100%), forehead protruding (100%), relative macrocephaly (100%), feeding difficulties/low BMI (33%), body asymmetry (0); ③ Skeletal abnormalities and pathogenesis were previously considered as the key points of differentiation also were overlaps between two diseases; ④ Symptomatic treatment and GH-treatment were carried out.Conclusions: ①. There isn’t reliable clinical points to distinguish the two diseases, especially for the patients with CUL7 mutations whose imaging is not typical, which need to rely on genetic detection; ②. Literature research points out the two diseases may have the same pathogenic pathway; ③. Both of diseases were treated symptomatically and used GH to improve height; ④. 3M syndrome diagnosed “clinical SRS” can incorporate into SRS to facilitate clinical classification and management.