Currently, Rett’s Disorder has been diagnosed only in females. The onset of this disorder is prior to age 4 and can begin as early as 5 months. The symptoms of Rett’s disorder are usually visibly noticeable at approximately age five. Individuals with Rett’s disorder are often referred to as “hand washers” because of their abnormal hand movements. These movements usually occur due to the loss of previously acquired hand skills. Other symptoms that occur are head growth deceleration, lack of interest in social environment, lack of coordination of torso movement, and impairment in expressive and receptive language.
The individual had normal prenatal and peri-natal development, as well as normal psychomotor development through the first 5 months after birth. Head circumference was normal at birth.
There is onset of all of the following after the period of normal development:
deceleration of head growth between ages 5 and 48 months
loss of previously acquired purposeful hand skills between ages 5 and 30 months, with subsequent development of stereotyped hand movements (e.g., hand washing or hand wringing)
appearance of poorly coordinated gait or trunk movements
severely impaired expressive and receptive language development with severe psychomotor retardation