Some aspects of the syndrome are progressive. Facial coarsening and skeletal involvement become more pronounced with age. Some motor and coordination neurological problems do not express themselves until later in childhood and may result in decreased mobility. Bone degeneration may occur starting in the late teen years which can lead to a higher incidence of broken bones. This is especially problematic for those who also have drop episodes as they are prone to spine and neck injuries from the repeated falls.  Depression or behavior problems may develop. Life expectancy may be reduced in individuals who have severe cardiac problems, respiratory complications, or severe progressive kyphoscoliosis.