They begin to worry as their child starts to lag behind their friend's children in development and they may feel they are being blamed for the child's overactive and difficult behavior. The diagnosis is often made very late as some children do not look abnormal and their symptoms are among the most common seen in all children. The doctor has to be perceptive enough to recognize thatr something serious is wrong and to ask for urine and blood tests to help reach a diagnosis. It is not unusual for families to have one or more affected children before the diagnosis is established. The second phase of the disorder is characterized by extremely active, restless and often very difficult behavior.
Some children sleep very little at night.
Many will be into everything. Sadly, language and understanding will gradually be lost and parents may find it hard not being able to have a conversation with their child. Many will find other ways of communicating. Some children never become toilet trained and those who do will eventually lose the ability. In the third phase of the disorder children with Sanfilippo Syndrome begin to slow down.