Early Phenotypic Features of Beta-Propeller Protein-Associated Neurodegeneration: Insights From a Korean Series.

Beta-propeller protein-associated neurodegeneration (BPAN) is a rare X-linked disorder caused by pathogenic variants in the WDR45 gene. Early diagnosis remains challenging because of nonspecific presentations in childhood. We report six pediatric patients with BPAN identified through genetic testing performed during evaluations of neurodevelopmental disorders. All the participants were female and exhibited early developmental delay, severe language impairment, and varying degrees of motor dysfunction. Seizures occurred in four patients with varying severity. Two patients showed signs of central precocious puberty. Serum neuron-specific enolase levels were elevated in all tested patients. Brain magnetic resonance imaging (MRI) revealed corpus callosum thinning in all the patients. Iron accumulation in the substantia nigra and globus pallidus was observed in only two older patients. WDR45 variants included two nonsense mutations, two splice sites, one in-frame deletion, and one novel frameshift deletion. Our findings highlight early clinical features that may aid in recognizing BPAN prior to the emergence of distinctive MRI abnormalities or degenerative-phase manifestations.