Beta-propeller Protein-Associated Neurodegeneration, the most common NBIA disorder, is caused by mutations in the WDR45 gene, located on the X chromosome. It is characterized by developmental delays and epileptic seizures in children, with movement problems in adulthood, including dystonia, disorders very similar to Parkinson’s.

To date, all affected individuals reported have been simple cases (i.e., only one occurrence in a family). The majority are females, indicating that the mutations are new, or de novo, and suggest that the mutations are fatal in most males. Affected people have an overall developmental delay during childhood with slow motor and cognitive gains. However, in adolescence or adulthood, they experience a relatively sudden onset of progressive dystonia such as parkinson’s and dementia.