Expanding the Phenotype: Four New Cases and Hope for Treatment in Bachmann-Bupp Syndrome

Bachmann-Bupp syndrome (BABS) is a rare condition caused by gain-of-function variants in the ODC1 gene, leading to developmental delay, macrocephaly, macrosomia, and non-congenital alopecia. The diagnosis of four new patients expanded the known phenotype to include late-onset seizures, observed in a 23-year-old patient. Neuroimaging abnormalities remained inconsistent, possibly due to unknown effects of ODC/polyamine dysregulation on brain development. Variants clustered around elevated ODC protein and enzyme activity, suggesting a universal biochemical mechanism. Recommendations for medical management and potential targeted molecular or metabolic testing were proposed. The natural history of BABS might evolve with DFMO therapy, prompting further research.