Clinical Characteristics for Families

Most children with AP-4-associated HSP have:

•    A “floppy” appearance in infancy due to low muscle tone
•    Increasing spasticity and paralysis in the lower limbs starting in early childhood
•    Delayed motor development
•    Poor or absent speech development
•    Moderate to severe intellectual disability
•    Microcephaly
•    Seizures including frequent seizures in the setting of fever

Other known features of AP-4-HSP can include the following (not every child will have these features):
•    Short stature
•    Dystonia (involuntary muscle contractions)
•    Ataxia (impaired balance and coordination)