SGBS is characterized by prenatal and postnatal macrosomia, typical craniofacial changes (with macrocephaly, coarse facial features, macrostomia, macroglossia, palate abnormalities), and frequently a mild to severe intellectual disorder with or without structural brain changes. Other variable characteristics include an excessive number of nipples, rectal diastasis / umbilical hernia, diaphragmatic hernia, congenital heart defects, urogenital malformations, and gastrointestinal (GI) abnormalities. Moreover, there may also be skeletal abnormalities (vertebral fusion, rib abnormalities, hip dysplasia), hand abnormalities (large hands and postaxial polydactyly).
The following tumors have been described for patients with SGBS: Wilms tumors and nephroblastomatosis, hepatic tumors, and neuroblastoma. One child with SGBS and medulloblastoma has been described.