Rare case of myelodysplastic syndrome with excess blasts 2 developing after adjuvant chemoradiotherapy for triple-negative breast cancer in a patient with Bloom syndrome

Bloom syndrome (BS) is a rare autosomal recessive disorder caused by a loss-of-function mutation in the BLM gene encoding an RecQ helicase involved in DNA repair and maintenance of chromosomal stability. In patients with BS, significant sensitivity to both DNA-damaging chemotherapy (CT) and ionizing radiation complicates the management of neoplasms by exacerbating comorbidities and predisposing to toxicities and poor outcomes.