ABSTRACT Poikiloderma with neutropenia (PN) is a rare autosomal recessive disorder characterized by poikiloderma, neutropenia, and recurrent infections. We present a patient with PN carrying a novel homozygous pathogenic variant in the USB1 gene (c.547delC, p.Leu183Trpfs82*), and reviewed 90 PN cases reported since 1991 (including one new case) in order to assess genotype–phenotype correlations. Early symptoms included erythematous rash and recurrent infections (44% and 27% at 6 months, respectively), poikiloderma (88% at 12 months), and hepatosplenomegaly or elevated liver enzymes (22% at 12 months). Photosensitivity (21%) had a median onset at 21 months. Nail dystrophy and palmoplantar hyperkeratosis emerged later (36–48 months). Growth delay occurred in 53%, and 54% showed dental anomalies such as caries, hypodontia, or peg‐shaped teeth. Notably, 17% developed malignancies—four non‐melanoma skin cancers and 11 hematologic malignancies (AML, MDS, or pre‐MDS), highlighting a significant oncogenic risk. Genetic analysis revealed 34 different pathogenic variants in the USB1 gene. Our findings underscore the importance of early recognition and long‐term cancer surveillance in PN patients and provide a foundation for further research into USB1 's role and the disorder's progression.
Becker et al. (Wed,) studied this question.