Rett's Disorder
First described by Andreas Rett between 1964 and 1966, Rett's Disorder was not widely recognized until 1983, when Dr. Bengt Hagberg and colleagues published a seminal paper on the illness. Rett's disorder is a rare pervasive developmental disorder that primarily affects females. It is usually fatal to males; most male babies who have Rett's disorder are stillborn, or die shortly after birth. Children with Rett's disorder appear to develop normally at first. Symptoms appear between five months and two years old, at which point affected children regress, losing previously mastered skills such as language and hand coordination. Normal coordinated movements and hand gestures are replaced with the stereotyped gestured associated with autism. The criteria for a Rett's Disorder diagnosis are (as quoted from the DSM-IV-TR):
A. All of the following:
(1) apparently normal prenatal and perinatal development
(2) apparently normal psychomotor development through the first 5 months after birth
(3) normal head circumference at birth
B. Onset of all of the following after the period of normal development:
(1) deceleration of head growth between ages 5 and 48 months
(2) loss of previously acquired purposeful hand skills between ages 5 and 30 months with the subsequent development of stereotyped hand movements (i.e., hand-wringing or hand washing)
(3) loss of social engagement early in the course (although often social interaction develops later)
(4) appearance of poorly coordinated gait or trunk movements
(5) severely impaired expressive and receptive language development with severe psychomotor retardation
