People in their 20s and 30s may lack self-care skills and independence. Common signs and symptoms during this time include:

• Seizures
• Acceleration of cognitive decline
• Sleep disturbance
• Continued regression of previously mastered skills to the point of loss of ability
• Gait (walking) disturbance
• AGU-specific facial features become more apparent for example: widely-spaced eyes, small ears, full lips, large tongue, broad nose