Abstract: Objective  To improve the understanding and diagnosis of congenital neutropenia(CN)  in children and explore the procedures by the use of gene mutation.Methods  Direct DNA sequencing of PCR were applied to analyze the whole genome.  The database were screened to conduct relevant sequence alignment.  The mutations were confirmed by reverse sequencing. Results  Propositus 1 had double heterozygous mutations, IVS3+1 G> T and c.915(E6):, while was in lack of G. Propositus 2 had heterozygous mutations: c.1004(exon1)c.1005(exon1) ,while in lack of  AA.Conclusion  Both of the two children with congenital neutropenia had abnormal gene mutation.  Gene diagnosis is of great significance to define congenital neutropenia and  provide the background for further clinical research as well as therapy in these patients.

Key words: neutropenia;genes, CXCR4 gene, G6PC3 gene