Introduction
Beta-propeller protein-associated neurodegeneration (BPAN) is a rare form of neurodegeneration with brain iron accumulation (NBIA). It was first described by Haack et al. in 2012, initially termed static encephalopathy of childhood with neurodegeneration in adulthood (SENDA) . BPAN is characterized by static psychomotor retardation in childhood followed by progressive deterioration in adolescence or young adulthood, featuring progressive dystonia, parkinsonism, and dementia. Pathogenic mutations in the WDR45 gene are responsible for BPAN, which constitutes about 7% of NBIA disorders .
Clinical Spectrum
BPAN presents with delayed psychomotor development and intellectual disability from infancy or early childhood. A significant proportion (74.6%) of patients develop progressive cognitive decline in adolescence or early adulthood. Epileptic seizures occur in 67.7% of patients and range from focal to generalized seizures, often improving with age . Movement disorders, including dystonia (73.3%) and parkinsonism (60.3%), typically emerge during adolescence or early adulthood, leading to severe motor disability .
Rett-like Features
Rett-like features are observed in 28% of patients, characterized by developmental regression, loss of purposeful hand skills, stereotypic hand movements, and bruxism. Most cases do not meet all diagnostic criteria for Rett syndrome .