Dr. Elizabeth Thiele: When we make the diagnosis of tuberous sclerosis in an individual, we then wonder if they have it as a result of a spontaneous mutation, meaning that when their DNA was replicating, a mutation was made causing them to have tuberous sclerosis complex. And in that situation, no one else in the family, including the parents would be affected. Other times, it's passed on through a family. So, if an individual has tuberous sclerosis, and they go on to have children, each child they have will have 50 percent chance of inheriting the mutation, and also inheriting this disorder of tuberous sclerosis complex. So that's called an autosomal dominant transmission. So, when we do make the diagnosis in an individual, it's very important to look not only at that individual, but their family members, their parents, their siblings, their children, to see if, perhaps, other people in the family may also have the disorder. And what we do know is that, within families, TS even resulting from the same mutation, can look very different in different individuals. So we have some families where some of the affected individuals are very mildly affected. It's often very difficult to tell they have tuberous sclerosis complex. Whereas their sisters or brothers may be severely affected and may be nonverbal, have very intractable seizure disorders and other significant problems.
© 2006 The General Hospital Corporation.