Background: Isolated myelosarcoma of infancy is a rare presentation of acute myelogenous leukaemia (AML). Because of its rarity and early onset in infancy underlying genetic predisposition is potentially relevant in disease initiation.
Methods and results: We report an oncologic emergency in an infant with thoracic and intraspinal aleukaemic myeloid sarcoma causing acute myelon compression and lower leg palsy. Whole-exome sequencing of the patient's germline DNA identified a rare PALB2 (OMIM 610355) variant (p.A1079S), which is located in a domain critical for the gene's proper function within the homology-directed repair pathway. In line with potential DNA damage repair defects mediated by the PALB2 deregulation, the patient's fibroblasts showed increased sensitivity towards radiation and DNA intercalating agents.
Conclusion: Therefore, we suggest PALB2 p.A1079S as a pathogenic variant potentially contributing to the here observed patient phenotype.
Keywords: PALB2; extramedullary myelogenous leukaemia; myeloid sarcoma; tumour suppressor.
© 2021 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals LLC.