Abstract: 【Abstract】 Objective To analyze gene mutation characteristics of a child with DNA ligase Ⅳ syndrome. Methods Clinical data were collected from a child with DNA ligase Ⅳ syndrome. Whole-exome sequencing was performed to detect gene mutations in the patient, and Sanger sequencing to verify the candidate variants in family members. Results Three heterozygous mutations c.467C>T（p.A156V）, c.833G>T（p.R278L）, c.1271-c.1275del （p.K424fs*20） were identified in the DNA ligase Ⅳ gene of the patient, and the mutation c.467C>T（p.A156V） was confirmed as a novel mutation. Conclusion The complex heterozygous mutations in the DNA ligase Ⅳ gene may contribute to DNA ligase Ⅳ syndrome in the child.

Key words: DNA ligases, Genetic testing, DNA ligase Ⅳ syndrome, Severe combined, immunodeficiency, DNA ligase Ⅳ gene