目的 探讨切-希二氏综合征（Chediak-Higashi综合征）的临床特点和遗传学特征。方法 采用家系全外显子组测序（trio-WES）鉴定致病基因，总结患儿临床资料，分析临床及遗传学特征。结果 患儿，男，1岁7个月，以“面部、四肢远端色素沉着，伴灰发1年余”为主诉就诊于复旦大学附属儿童医院皮肤科。Trio-WES检测发现LYST基因存在复合杂合变异，为c.2962C>T，c.10564+1dupG，其中剪接位点变异为新发(de novo) 变异，符合常染色体隐性遗传模式，最终诊断为LYST基因变异导致的切-希二氏综合征。结论 LYST基因变异案例目前报道较少，本案例鉴定的变异是未见报道的，扩充了LYST基因缺陷的基因型-表型谱，也为进一步了解切-希二氏综合征提供数据。精确诊断依赖分子遗传学检测，需积累更多病例进一步分析基因型-表型关系和预后评估。

Objective To explore the clinical characteristics and genetic features of Chediak-Higashi syndrome. Methods Trio whole-exome sequencing (trio-WES) was performed to identify the pathogenic gene variant. The clinical data of the child were summarized, and the clinical and genetic characteristics were analyzed. Results The patient, a 1-year and 7-month-old boy, presented to the dermatology department of the Children's Hospital of Fudan University with the chief complaints of pigmentation on the face and distal limbs, accompanied by gray hair for over one year. Trio-WES revealed compound heterozygous mutations in the LYST gene (c.2962C>T, c.10564+1dupG). The splicing site mutation (c.10564+1dupG) was a de novo variant. The inheritance pattern was consistent with autosomal recessive inheritance. A final diagnosis of Chediak-Higashi syndrome caused by LYST gene mutations was made. Conclusion Cases of Chediak-Higashi syndrome caused by LYST gene mutations are rarely reported. The variant combination identified in this case is previously unreported, which expands the genotype-phenotype spectrum of LYST gene defects and provides further data for understanding Chediak-Higashi syndrome. Precise diagnosis relies on molecular genetic testing. More cases need to be accumulated to further analyze the genotype-phenotype correlation and prognostic evaluation.