A case report of de novo ELANE c.416C>T mutation causing cyclic neutropenia in a 7-year-old girl

Objective: ELANE mutation, to improve clinical recognition and care. Methods: 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. Results: heterozygous ELANE c.416C>T (p.Pro139Leu) variant. The Pro139 residue is highly conserved across species, and substitution is predicted to impair neutrophil elastase structure and function. The patient responded well to recombinant human granulocyte colony-stimulating factor (rhG-CSF) plus infection control and supportive care and is currently awaiting hematopoietic stem cell transplantation (HSCT). Conclusion: c.416C>T variant broadens the genotypic spectrum of ELANE-related CN. Early and accurate diagnosis, individualized treatment, and long-term follow-up are critical to improve outcomes.