ABSTRACT
Objective:To investigate the clinical and genetic characteristics of Simpson-Golabi-Behmel syndrome (SGBS) type Ⅰ caused by glypican-3 ( GPC3) gene mutations. Methods:Data of one neonate with SGBS type Ⅰ from Shenzhen Maternity and Child Healthcare Hospital Affiliated to Southern Medical University was reviewed retrospectively. Literature was retrieved to summarize the clinical and genetic characteristics of SGBS type Ⅰ caused by GPC3 mutations, using terms of "Simpson-Golabi-Behmel type Ⅰ", "GPC3" and "glypican-3" from China National Knowledge Infrastructure, VIP database, Wanfang database, and PubMed from January 2010 till April 2021. Results:The male infant was admitted to the hospital at 4 h after birth due to "abdominal distension for 1 h", presenting with dysmorphic facial features, including macrocephaly, coarse face, broad nasal bridge, macrostomia, tongue with a groove in the middle, as well as macrosomatia, supernumerary nipples, and hypospadias. Whole exome sequencing revealed a novel frameshift mutation (c.720delC) in GPC3 gene of the patient and his mother for hemizygous and heterozygous variation, respectively, based on which SGBS type Ⅰwas confirmed. During the follow-up, overgrowth, neuroblastoma, and motor development retardation were found in the boy. In addition to the index patient, 92 cases of SGBS type Ⅰ reported in 31 articles were analyzed, including 89(95.7%) males and 4(4.3%) females. The main clinical features were craniofacial dysmorphism, pre/postnatal overgrowth with multiple congenital anomalies. Most patients were combined with language disorders, motor retardation, and various degrees of dysnoesia, and were more likely to develop embryonic tumors. Among the 93 cases, 11(11.8%) suffered from tumors. Apart from 21 cases of termination, 63 cases were born alive and nine cases died after birth. Pathogenic variants in GPC3 gene were reported in 80 cases, which were nonsense mutation in 25 cases (31.2%), DNA fragment deletion in 21 cases (26.2%), frameshift mutation in 16 cases (20.0%), large duplications in eight cases (10.0%), missense mutation in five cases(6.2%), and splice site mutation in five cases(6.2%). Conclusions:SGBS type Ⅰ is an X-linked recessive genetic disease with various phenotypes. Patients with postnatal craniofacial dysmorphism, overgrowth, and multiple congenital anomalies should be highly suspected of SGBS type Ⅰ. Genetic testing is conducive to its early diagnosis. Treatment requires multidisciplinary cooperation and long-term follow-up, especially for those with tumors.