Simpson-Golabi-Behmel Syndrome (SGBS) is an X-linked disorder characterized by pre- and postnatal overgrowth and distinctive facial features. Macrosomia and macrocephaly are typically noted on prenatal ultrasound or at birth and continue throughout development. The facial features are described as “coarse” and may include hypertelorism, downslanting palpebral fissures, epicanthal folds, macrostomia, macroglossia, a wide nasal bridge, ear pits or tags, and a central groove of lower lip and/or tongue. The risk for congenital anomalies is increased, including cleft lip/palate, congenital heart disease, diaphragmatic hernia, umbilical hernia, cystic hygroma, renal dysplasia, cryptorchidism, and hypospadias. Other common findings may include hypotonia, fingernail hypoplasia, interdigital webbing, polydactyly, supernumerary nipples, pectus excavatum, and skeletal anomalies. As with other overgrowth syndromes, hypoglycemia may occur in the neonatal period, and hepatomegaly has been described (Neri et al., 1998). The risk for embryonal tumors is increased but is not well established. Previous cases of Wilms tumor, hepatoblastoma, adrenal neuroblastoma, gonadoblastoma, and hepatocellular carcinoma have been published (Lapunzina 2005). Some individuals with SGBS have normal intelligence, while others exhibit mental retardation that may range from mild to severe. Even among individuals with normal intelligence, speech delay occurs frequently and may be secondary to macroglossia and malocclusion (Rodriguez-Criado et al., 2005).