WHAT IS BPAN?
Beta-propeller protein-associated neurodegeneration (BPAN) is a disorder that damages the nervous system and is progressive, which means that it gradually gets worse. Affected individuals develop a buildup of iron in the brain that can be seen with medical imaging. For this reason, BPAN is classified as a type of disorder called neurodegeneration with brain iron accumulation (NBIA), although the iron accumulation may not occur until late in the disease.
This damage leads to delayed development and recurrent seizures (epilepsy) beginning in infancy or early childhood, movement problems that get worse over time, and a gradual loss of intellectual functioning in adulthood. Affected individuals eventually have a buildup of iron in the brain that can be seen with medical imaging; for this reason, BPAN is classified as a type of disorder called neurodegeneration with brain iron accumulation (NBIA).
Children with BPAN also have intellectual disability, delayed development including significant problems with vocabulary and producing speech (expressive language), and difficulty coordinating movements (ataxia). Ataxia can affect the ability to walk and perform fine motor skills such as using utensils. Affected individuals can have behavioral changes that are often compared to features of a disorder called Rett syndrome. These features include repeated hand wringing or clasping (stereotypic hand movements); teeth grinding (bruxism); sleep disturbances; and problems with communication and social interaction characteristic of autism spectrum disorder.
In late adolescence or early adulthood, individuals with BPAN may begin to experience a gradual loss of intellectual functioning (cognitive decline) that can lead to a severe loss of thinking and reasoning abilities (dementia). Worsening problems with movement also occur, including dystonia and parkinsonism. Dystonia is a condition characterized by involuntary, sustained muscle contractions. In BPAN, the dystonia often starts in the arms. Parkinsonism can include unusually slow movement (bradykinesia), rigidity, tremors, an inability to hold the body upright and balanced (postural instability), and a shuffling walk that can cause recurrent falls.
The lifespan of people with BPAN varies. With proper management of their signs and symptoms, affected individuals can live into middle age. Death may result from complications of dementia or movement problems, such as injuries from falls or swallowing difficulties (dysphagia) that can lead to a bacterial lung infection called aspiration pneumonia.