RÉSUMÉ
Objective:To study the clinical and genetic features of neonatal Schaaf-Yang Syndrome (SYS).Methods:The clinical data of a newborn with SYS admitted to our hospital in October 2022 were retrospectively analyzed. Using "Schaaf-Yang syndrome", "newborn", "preterm", "neonate" as keywords, we searched the CNKI, Wanfang Database, VIP database, Chinese Medical Journal Full Text Database, PubMed, Embase, Web of Science and the Cochrane Library for literature published during the date of establishment to March 24th, 2023. The clinical and genetic features of neonatal SYS from published literature were summarized.Results:The patient in this case was a female preterm infant with a gestational age of 33 +3 weeks, characterized by epiglottic collapse, hypotonia, poor response, weak sucking and swallowing, respiratory failure, and abnormalities such as bilateral low ear position and short limbs. The patient received symptomatic treatment, often failed to withdraw the ventilator, and had difficulty intubating. Meanwhile, whole exome sequencing identified a de novo truncated variant c.2892del (p.Trp965Glyfs*3) in the MAGEL2 gene of the patient. At 30 d after birth, the patient died after giving up treatment by her family. A total of 11 retrieved literatures had neonatal records, including 17 cases. The clinical features involved joint contracture (15/17), hypotonia (14/17), respiratory failure (12/17), and feeding difficulties (12/17). Most of the gene variation was truncated mutation, and only 1 heterozygote deletion mutation was found. These gene variation included c.1996dupC(p.Gln-666Profs*47) variation in 7 cases, c.1912C>T(p.Q638X) variation in 3 cases, c.1996C>T(p.Q666*) in 1 case, c.2847-2883del37 in 1 case, c.2118delT(p.Leu708Trpfs*7) in 1 case, c.1850G>A(p.RP617*) in 1 case, c.2167delG (p.Ala723Profs*4) in 1 case, c.2005C>T(p.Gln669) in 1 case, c.2892del(p.Trp965Glyfs*3) in 1 case, respectively. Conclusions:The main manifestations of neonatal SYS included hypotonia, feeding difficulties, respiratory failure and joint contracture. Most of the mutations were truncated mutations of c.1996dupC (p.Gln-666Profs*47).