Rett’s Disorder

Rett's Disorder is a childhood disorder characterized by multiple developmental deficits following a period of normal functioning after birth.

Symptoms include:

All of the following:

• Apparently normal prenatal and perinatal development.

• Apparently normal psychomotor development through the first 5 months after birth.

• Normal head circumference at birth.

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 the subsequent development of stereotyped hand movements (e.g., hand-wringing or hand washing).

• Loss of social engagement early in the course (although often social interaction develops later.

• Appearance of poorly coordinated gait or trunk movements.

• Severely impaired expressive and receptive language development with severe psychomotor retardation.

Associated Features and Disorders

Rett's Disorder is typically associated with Severe or Profound Mental Retardation, which, if present, should be coded on Axis II. There are no specific laboratory findings associated with the disorder. There may be an increased frequency of EEG abnormalities and seizure disorder in individuals with Rett's Disorder. Nonspecific abnormalities on brain imaging have been reported. Preliminary data suggest that a genetic mutation is the cause of some cases of Rett's Disorder.

Course

The pattern of developmental regression is highly distinctive. Rett's Disorder has its onset prior to age 4 years, usually in the first or second year of life. The duration of the disorder is lifelong, and the loss of skills is generally persistent and progressive. In most instances, recovery is quite limited, although some very modest developmental gains may be made and interest in social interaction may be observed as individuals enter later childhood or adolescence. The communicative and behavioral difficulties usually remain relatively constant throughout life.

Diagnostic criteria summarized from:

American Psychiatric Association. (1994). Diagnostic and statistical manual of mental disorders, fourth edition. Washington, DC: American Psychiatric Association.