We describe the clinical phenotype, diagnostic features, and management of a pediatric CN case caused by a <i>de novo</i> ELANE mutation, to improve clinical recognition and care.<h4>Methods</h4>We retrospectively analyzed clinical, laboratory, and genetic data from a 7-year-old girl with CN, combined with bioinformatics and literature review to explore genotype-phenotype correlations and optimal therapy.<h4>Results</h4>The patient presented with classic 21-day cyclic episodes of fever, oral ulcers, and lymphadenopathy. This evidence concerns the gene ELANE and cyclic hematopoiesis.