关键词: Langer-Giedion综合征, Cornelia de Lange综合征4型, 基因突变

Abstract: Objective To report and analyze the clinical characteristics of a child with Langer-Giedion syndrome (LGS) combined with Cornelia de Lange syndrome type 4 (CdLS4), and to review the literature in order to improve understanding of the clinical phenotypes and differential diagnosis of contiguous gene deletion syndromes. Methods A retrospective analysis was conducted on the clinical data of one patient with LGS co-occurring with CdLS4 who was admitted to the Department of Pediatrics, Peking Union Medical College Hospital in October 2024. Relevant literature was also reviewed. Results The patient was an 8-year-old boy whose main clinical features included characteristic facial appearance (thick eyebrows, mild synophrys, long eyelashes, prominent ears, broad nasal bridge, bulbous nasal tip, long philtrum, and thin upper lip), language developmental delay, intellectual disability, multiple osteochondromas, and skeletal abnormalities. Genetic testing revealed a heterozygous copy number deletion of approximately 2.2 Mb in chromosome 8q23.3-q24.12, involving the RAD21, EXT1, and TRPS1 genes, which was classified as pathogenic. He was diagnosed with Langer-Giedion syndrome combined with Cornelia de Lange syndrome type 4. Literature review showed that when deletions involve multiple genes in this region, patients may present overlapping phenotypes of both syndromes. In the early stages, reliance solely on clinical manifestations makes differentiation difficult, leading to a risk of misdiagnosis or delayed diagnosis. Conclusions LGS and CdLS4 share partially overlapping clinical phenotypes, and contiguous gene deletions can result in combined manifestations of multiple syndromes. Genetic testing enables definitive diagnosis and helps avoid misdiagnosis. This case highlights the importance of comprehensive genetic evaluation in children with developmental delay and multiple congenital anomalies, and the need for individualized long-term management plans under multidisciplinary collaboration.

Key words: Langer-Giedion syndrome, Cornelia de Lange syndrome type 4, gene mutation