Genetic aspects of Rett syndrome.

To date over 1,000 cases of Rett syndrome have been described in females exclusively. Some of these cases, less than 2 in 100, are familial. The inheritance through maternal lines in the familial cases suggests that Rett syndrome is an X-linked disorder lethal in males. Hypotheses about the genetic mechanisms involved in this syndrome along with suggestions to approach the molecular basis of this disorder are presented.