Rett's syndrome is one disorder in the autism spectrum. It is almost exclusively seen in girls and is due to a genetic mutation on the X chromosome. Since boys have only one X chromosome, this disorder is fatal and most boys are stillborn or die soon after birth. Girls with Rett's begin showing symptoms first in infancy when their head stops growing. This happens slowly which sometimes is missed. These children's disabilities do not get better with age but some will live to be middle-aged. However, they will need constant care throughout their lives and will never have any kind of independence.
Many parents are now raising the question of what will happen to their children once they are no longer able to care for them. For the milder forms of ASD such as Asperger's syndrome, they may have limited independence. In the long term, if there is no family member that can take care of them, they may end up in a group home or worse, residential care. Generally, federal aid for services ends in early adulthood and the families are left to rely on families and friends.
Out of all the caretaking the parents do, probably the one thing that they could change would be the social isolation. Parents who have children with autism over time stop going to social engagements because of the criticisms they receive for their children's 'acting out'. There are support groups available, but many are unable to attend due to not having an appropriate babysitter.
For more resources and support, contact the Autism Society. They have many resouces and contact information for local chapters/support groups.