Abstract: Objective　To explore the gene variation and clinical manifestation of Cornelia de Lange syndrome. Method The clinical information and data of whole-genome second-generation sequencing of a suspected Cornelia de Lange syndrome in a child were collected. Results　The 6-month-old boy had growth retardation and distinctive facial features (hairy forehead, synophrys, thick arched eyebrows, long and curved eyelashes, drooping double eyelids, low bridge of the nose, long philtrum, thin lips, and downslanting corners of the mouth). Heterozygous mutation of c.1679dela (p.k566sfs * 48) was detected in exon 9 of NIPBL gene in the child, which was a new mutation and had not been reported in literature. There was no abnormality in this gene locus in both of his parents. According to the guidelines of the American College of Medical Genetics and Genomics, the mutation site is pathogenic variation. Conclusion　A new truncated protein mutation was detected in NIPBL gene in a Cornelia de Lange syndrome patient, which had not been reported in the literature. It enriched the human gene mutation database.

Key words: Cornelia De Lange syndrome;　NIPBL gene;　whole exon sequencing