DIAGNOSIS & SYMPTOMS
Many years and detours often occur before an accurate diagnosis is obtained.
The symptoms for each type NBIA are different and can occur in different timeframes. Even within BPAN there is a wide range of symptoms, they can appear early or in adolescence/adulthood and there are differences between male and female symptoms. Sometimes in childhood developmental delay or seizures are the 1st significant symptoms. In some individuals, they develop normally and lose the ability to walk, talk and eat. The diagnosis is by identifying a pathogenic variant in the WDR45 gene by molecular genetic testing.
The symptoms of BPAN change significiantly from childhood to adolescence. During childhood there is developmental delay with slow motor and cognitive gains. Intellectual disability is marked and most children attain on a few spoken words. Some experience seizures and sleep disorders. During adolescence or early adulthood, signs of parkinsonism emerge, sometimes very suddenly. If the child was able to learn to walk, now those skills are lost and the posture becomes slooped, movements slow, and the gait changes with periodic freezing. These symptoms may be briefly relieved by medication but they have to be discontinued due to serious side effects. Additionally, there is progressive cognitive decline and previously learned skills are lost. Eventually all patients lose ambulatory ability and experience an onset of dementia.