Severe congenital neutropenia type 1 (SCN1) is a rare hereditary disorder caused by a maturation arrest in granulocyte development, most frequently associated with mutations in the ELANE gene, which encodes neutrophil elastase.
Female patient, 3 years and 5 months old, with a history of recurrent perianal infections and necrotizing fasciitis secondary to complicated appendicitis with septic shock. She required laparotomy, appendectomy, ileostomy, debridement, and vasopressor support. During hospitalization, persistent severe neutropenia, lymphopenia, and eosinophilia were identified. Bone marrow aspiration showed a maturation arrest in the myeloid lineage with absence of neutrophils. Infectious isolates included Pseudomonas aeruginosa, Stenotrophomonas maltophilia, and rhinovirus/enterovirus. Absolute neutrophil counts remained persistently low (100–530/μL), with a response to the administration of G-CSF (granulocyte colony stimulating factor: 5 mcg/kg/dose). Genetic sequencing revealed a heterozygous nonsense mutation in ELANE (c.684C>G, p.Tyr228Ter).
The diagnosis of SCN1 was clinically supported by severe infections, persistent neutropenia, absence of mature granulocytes in the bone marrow, and genetic confirmation. This mutation generates a premature stop codon. Other relevant variants include GFI1, HAX1, VPS45, JAGN1, CSF3R, and WAS.
SCN1 should be suspected in pediatric patients with recurrent severe infections and persistent neutropenia. Early identification and treatment with G-CSF may improve clinical outcomes and reduce infectious complications.
