摘要目的:探讨1例Schaaf-Yang综合征(SYS)患儿的诊疗过程与遗传学分析。方法:以2020年6月10日就诊于湖南省儿童医院的1例SYS患儿作为研究对象。对患儿及其父母进行全外显子组检测，对候选变异进行Sanger测序家系验证。通过预测野生型与变异型蛋白的结构来分析其危害性。结果:基因检测提示患儿携带 MAGEL2基因杂合移码变异c.1908delG(p.R637Gfs*65)，其父母该位点均为野生型，提示为新发。该变异未被相关公共数据库收录，既往未见文献报道。该变异可造成 MAGEL2蛋白仅保留部分脯氨酸结构域，导致蛋白功能破坏或下调。 结论:MAGEL2基因的c.1908delG(p.R637Gfs*65)新发变异可能是本研究患儿的遗传学病因，结合其临床特征诊断为SYS。上述发现丰富了 MAGEL2基因的变异谱。

abstractsObjective:To explore the diagnosis, treatment and genetic analysis of an infant with Schaaf-Yang syndrome (SYS).Methods:An infant suspected for SYS at the Hunan Provincial Children′s Hospital on June 10, 2022 was subjected to trio-whole exome sequencing, and Sanger sequencing was used to verify the candidate variant. Structure of the wild-type and variant proteins was constructed to analyze the potential hazard.Results:The infant was found to harbor a heterozygous frameshifting variant of c. 1908delG (p.R637Gfs*65) of the MAGEL2 gene, which was found in neither of his parents. The variant has not been recorded by the public databases, and no relevant literature was retrieved. As the result of the variant, the MAGEL2 protein only retained part of its proline domain, which may lead to destruction and/or down-regulation of its function. Conclusion:The c. 1908delG (p.R637Gfs*65) variant of the MAGEL2 gene probably underlay the pathogenesis in this child. Combined with his clinical characteristics, the child was diagnosed with SYS. Above finding has also enriched the mutational spectrum of the MAGEL2 gene.