From clinical findings to the pathomechanism of poikiloderma with neutropenia.

The clinical problem of a non‐healing fistula in ano in a child affected with poikiloderma with neutropenia (PN) was the stimulus for an innovative study by Parajuli et al. that sheds light on the pathological mechanisms in this disease. Multiparametric analyses of the patient's blood mononuclear cells by cell culture, flow cytometry and multiplex cytokine assay suggested a block of monocyte differentiation. Monocyte transcriptome profiling revealed a signature consistent with the haematological picture and the clinical presentation. Commentary on: Parajuli et al. Defective monocyte plasticity and altered cAMP pathway characterize USB1‐mutated poikiloderma with neutropenia Clericuzio type. Br J Haematol 2024;204:683‐693. [ABSTRACT FROM AUTHOR]