Fanconi Anemia Neuroinflammatory Syndrome (FANS): Brain Lesions and Neurologic Injury in Fanconi Anemia.

Fanconi anemia (FA) is a complex inherited bone marrow failure syndrome characterized by chromosomal instability and defective DNA repair causing sensitivity to DNA interstrand cross-linking agents. Our understanding of the full adult phenotype of the disease continues to evolve, as most patients with Fanconi Anemia died of marrow failure in the first decade of life prior to more recent advances in allogeneic hematopoietic cell transplantation. Herein, we report a previously undescribed, clinically concerning, progressive neurologic syndrome in patients with FA. Nine non-immunosuppressed pediatric patients and young adults with FA presented with acute and chronic neurological signs and symptoms associated with distinct neuroradiological findings. Symptoms included, but were not limited to, limb weakness, papilledema, gait abnormalities, headaches, dysphagia, visual changes, and seizures. Brain imaging demonstrated a characteristic radiographic appearance of numerous cerebral and cerebellar lesions with associated calcifications and often a dominant ring enhancing lesion. Tissue from the dominant brain lesions in 4 patients showed non-specific atypical glial proliferation, and a small number of polyomavirus infected microglial cells identified by immunohistochemistry in 2 patients. Numerous interventions were pursued across this cohort, in general with no improvement. Overall, these patients demonstrated significant progressive neurologic decline. This cohort highlights the importance of recognizing Fanconi Anemia Neuroinflammatory Syndrome (FANS), which is distinct from malignancy and warrants careful ongoing evaluation by clinicians.