Game of clones: A case of ELANE gene mutation-related neutropenia

Abstract

Mutations in the ELANE gene, which encodes the neutrophil elastase (NE) protein in neutrophils, result in ELANE-related neutropenia. ELANE-related neutropenia encompasses both cyclic neutropenia (CN) and severe congenital neutropenia (SCN), with ELANE mutations seen in a majority of SCN and almost all of CN patients. Clinical history in affected individuals typically reveals recurrent episodes of fever, oral ulcerations and bacterial as well as fungal infections, correlating with periodic oscillations or chronically low levels in the absolute neutrophil count (ANC). ELANE-related neutropenia is characterised by severely low neutrophil counts where ANCs may drop as low as zero. A two-year-old child presented at our hospital with a longstanding history of recurrent bacterial infections and previous admissions at another centre during some of these infectious episodes. Her full blood count demonstrated a markedly low ANC, which was chronic on assessment of her previous results. Decreased granulopoiesis with maturation arrest was seen on her bone marrow and genetic testing for the ELANE gene demonstrated a pathogenic variant of the mutation. Treatment with granulocyte colony-stimulating factor (G-CSF) was initiated.