De novo CXCR4 Mutation in WHIM Syndrome: Report of a 4-year- old Case Without Wart and Myelokathexis

WHIM syndrome ( Warts, Hypogammaglobulinemia, Immunodeficiency, and Myelokathexis syndrome), a type of severe congenital neutropenia (SCN), involves Warts, Hypogammaglobulinemia, Infections, and Myelokathexis as its main components of clinical presentation, which results from mutations in the C-X-C chemokine receptor type 4 (CXCR4) gene. Here, we present an Iranian 4-year-old girl with severe congenital neutropenia without warts and normal bone marrow examination, lacking evidence of myelokathexis. Whole Exome Sequencing (WES) was performed for the patient. Subsequently, Sanger segregation/validation was done of the patient and her parents. Whole exam sequencing identified a heterozygous stop variant mutation in CXCR4 (NM_001008540.2:c.1012C>T; p.Arg338Ter) in the patient. Two of the main clinical criteria in WHIM syndrome, including warts and myelokathexis, were not observed in our patient. So, the absence of warts is not deceptive in ruling out the disease. This case report also represents the high importance of genetic analysis as a primary tool for the accurate differential diagnosis of patients with neutropenia.