目的 探讨CHD1基因新发变异导致1例全面发育落后患儿的临床特征及基因突变的特点，研究其与Pilarowski-Bjornsson综合征(PILBOS，OMIM#617682)关系。方法 采用家系全外显子组测序(trio whole-exome sequencing，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，8月龄，以“发现发育落后6月余”为主诉就诊于我院小儿神经内科。Trio-WES检测发现染色体5q15-q21的CHD1基因1号外显子存在c.13A>G(p.Ser5Gly) 错义变异(转录本号NM_001270)，为新发(de novo)变异，符合常染色体显性遗传模式，最终诊断为“CHD1基因缺陷导致的全面性发育落后”。结论 CHD1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CHD1基因缺陷的基因型-表型谱，也为进一步了解PILBOS疾病提供数据。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 features and genetic mutation characteristics of a case of global developmental delay caused by a novel variant in the CHD1 gene, and to investigate its relationship with Pilarowski- Bjornsson syndrome (PILBOS, OMIM# 617682). Method Trio whole-exome sequencing (trio-WES) was performed to identify the pathogenic gene within the pedigree, and the clinical data of the patient were summarized to analyze both clinical and genetic characteristics. Result The patient was an 8-month-old male and presented to the Department of Pediatric Neurology at our hospital with the main complaint of " developmental delay for more than six months". Trio-WES detection revealed a missense mutation in exon 1 of the CHD1 gene on chromosome 5q15-q21, with a c.13A>G (p.Ser5Gly) mutation (transcript number NM_001270), which represented a novel (de novo) variation consistent with an autosomal dominant inheritance pattern. The final diagnosis was" Comprehensive developmental delay caused by CHD1 gene deficiency". Conclusion There are currently few reports on cases of CHD1 gene mutations, and the identified mutations in this case has not been previously documented. Expanding the genotype phenotype spectrum of CHD1 gene defects also provides data for further understanding of PILBOS disease. Accurate diagnosis relies on molecular genetic testing, and additional cases need to be accumulated for further analysis of genotype phenotype relationships and prognosis evaluation.