A Novel Homozygous HAX1 Mutation in a Child With Cyclic Neutropenia: A Case Report and Review.

BACKGROUND Cyclic neutropenia is a rare genetic disorder causing the arrest of neutrophil function and is characterized by periodic neutropenia and recurrent infections. Patients with cyclic neutropenia with autosomal dominant, sporadic, and X-linked may have mutations in the ELANE gene, and autosomal recessive cases have homozygous/compound heterozygous variants in the HAX1 gene primarily. OBSERVATION The authors describe a novel variant in the HAX1 gene, which was detected by next-generation sequencing in an 8-year-old male child who presented with recurrent infections and neutropenia. CONCLUSION The patient extends the clinical variability associated with HAX1 variants and highlights the importance of genetic investigations in patients with suspected cyclic neutropenia.