摘要目的:探讨1例脊椎眼综合征(SOS)患儿的临床特征及遗传学病因，加强对SOS的认识与理解。方法:选取2023年8月10日因"反复骨折2年余，双眼白内障术后"就诊于湖南省儿童医院医学遗传科的1例SOS男性患儿(3.5岁)为研究对象。收集相关临床资料，采集家系成员外周血样、提取基因组DNA并进行全外显子组测序(WES)，用Sanger测序对候选变异进行验证，并对变异位点进行致病性分析。本研究通过了湖南省儿童医院医学伦理委员会的审查(伦理号：KYSQ2022-263)。结果:患儿有反复骨折、双侧股骨弯曲、骨质疏松、白内障、房间隔缺损、发育迟缓等临床表现，产前超声示胎儿水肿、腹腔积液、胸腔积液、羊水多。家系WES及Sanger测序显示患儿 XYLT2基因存在c.1103_1104delAG(p.Gln368Argfs*8)和c.1238_1253delinsA(p.Val413_Pro418delinsGlu)复合杂合变异，分别遗传自临床表型无异常的父亲和母亲。该2个变异既往均未见报道，根据美国医学遗传学与基因组学学会(ACMG)相关指南与临床基因组资源中心(ClinGen)专家组建议，c.1103_1104delAG被判定为致病性变异(PVS1＋PM2_Supporting＋PP4)，c.1238_1253delinsA被判定为可能致病性变异(PM4＋PM3＋PM2_Supporting＋PP4)。 结论:XYLT2基因c.1103_1104delAG和c.1238_1253delinsA复合杂合变异可能为上述SOS患儿的遗传学病因。上述研究成果进一步丰富了SOS的表型谱与变异谱，为该病患者的临床诊疗、预后评估、家系再生育咨询等提供了依据。

abstractsObjective:To explore the clinical characteristics and genetic etiology of a child with Spondyloocular syndrome (SOS) in order to enhance the awareness and understanding of this disease.Methods:A 3.5-year-old boy with SOS who had presented at the Department of Medical Genetics of Hunan Children′s Hospital on August 10, 2023 due to the repeated fractures for over 2 years and after binocular cataract surgery was selected as the study subject. Clinical data of his pedigree were collected, and peripheral venous blood samples were collected for the extraction of genomic DNA and subjected to trio-whole exome sequencing. Candidate variants were verified by Sanger sequencing and analyzed with bioinformatic software. This study was approved by the Medical Ethics Committee of Hunan Children′s Hospital (No. KYSQ2022-263).Results:The child had manifested repeated fractures, bilateral bowed femur, osteoporosis, cataract, atrial septal defect, and developmental delay. Ultrasonography has revealed fetal edema, peritoneal effusion, pleural effusion and polyhydramnios. Trio-whole exome sequencing and Sanger sequencing revealed that he has harbored compound heterozygous variants of the XYLT2 gene, namely c. 1103_1104delAG (p.Gln368Argfs*8) and c. 1238_1253delinsA (p.Val413_Pro418delinsGlu), which were inherited from his phenotypically normal father and mother, respectively. Neither variant was reported previously. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG) and recommendations from the Clinical Genome Resource (ClinGen), the c. 1103_1104delAG was predicted as a pathogenic variant (PVS1+ PM2_Supporting+ PP4), whilst the c.1238_1253delinsA was predicted as a likely pathogenic variant (PM4+ PM3+ PM2_Supporting+ PP4). Conclusion:The c. 1103_1104delAG and c. 1238_1253delinsA compound heterozygous variants of the XYLT2 gene probably underlay the pathogenesis in this child. Above finding has enriched the phenotypic and mutational spectrum of SOS, and provided a basis for the clinical diagnosis, treatment, prognosis assessment and genetic counseling for this pedigree.