Girls with Rett Syndrome appear to develop normally until 6 to 18 months of age. They then enter a period of regression, losing speech and hand skills they had acquired. Most girls develop seizures, repetitive hand movements, irregular breathing and motor-control problems. A slowing of the rate of head growth also
becomes apparent. Most researchers agree that RS is a developmental disorder rather than a progressive, degenerative disorder. The girls can live to adulthood, but most never regain the ability to use their hands or to speak.


All of the following: (a) apparently normal prenatal and perinatal development
(b) apparently normal psychomotor development through the first 5_months after birth
(c) normal head circumference at birth

Onset of all of the following after the period of normal development: (a) deceleration of head growth between ages 5 and 48 months
(b) 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)
(c) loss of social engagement early in the course (although often social interaction develops later)
(d) appearance of poorly coordinated gait or trunk movements
(e) severely impaired expressive and receptive language development with severe psychomotor retardation


Symptoms not required for the diagnosis, but which also may be seen. These features may not be observed in the young girl but may evolve with age.
Breathing dysfunctions which include breath holding or apnea, hyperventilation and air swallowing which may result in abdominal bloating and distention
EEG abnormalities -- slowing of normal electrical patterns, the appearance of epileptiform patterns and loss of normal sleep characteristics
Muscle rigidity/spasticity/joint contractures which increase with age
Scoliosis (curvature of the spine)
Teeth grinding (bruxism)
Small feet ( in relationship to stature)
Growth retardation
Decreased body fat and muscle mass (but tendency toward obesity in some adults)
Abnormal sleep patterns and irritability or agitation
Chewing and/or swallowing difficulties
Poor circulation of the lower extremities, cold and bluish-red feet and legs
Decreased mobility with age

All girls and women with RS do not display all of these symptoms, and individual symptoms may vary in severity. A pediatric neurologist or developmental pediatrician should be consulted to confirm the clinical diagnosis.

NINDS Rett Syndrome Information Page
Manitoba Rett Syndrome Association
Rett Syndrome Fact Sheet
General Health Encyclopedia: Rett Syndrome
Rett Disorder/Syndrome
Family Village
Link Between Autism and Rett Disorder Found
Rett Disorder and the Developing Brain
Club Rett: Yahoo! Group for adults 


Childhood Disintegrative Disorder (also known as Heller's Syndrome) is a condition in which a child develops normally for 2 years, then begins to lose ground. Previous gains in language and social skills, motor abilities, play, and even in continence are eroded.  For more information, click here.

Diagnostic criteria for 299.10 Childhood Disintegrative Disorder

 A.    Apparently normal development for at least the first 2 years after birth 
           as manifested by the presence of age- appropriate verbal and nonverbal 
           communication, social relationships, play, and adaptive behavior.

 B.   Clinically significant loss of previously acquired skills (before age 10 years) 
           in at least two of the following areas:

          (1) expressive or receptive language
          (2) social skills or adaptive behavior
          (3) bowel or bladder control
          (4) play
          (5) motor skills

C.   Abnormalities of functioning in at least two of the following areas:

         (1)  Qualitative impairment in social interaction 
              (e.g., impairment in nonverbal behaviors, failure to develop peer 
               relationships, lack of social or emotional reciprocity)
         (2)  qualitative impairments in communication (e.g. delay or lack of spoken 
               language, inability to initiate or sustain a conversation, stereotyped and 
               repetitive use of language, lack of varied make-believe play).
         (3)  restricted, repetitive, and stereotyped patterns of behavior, interests, and 
               activities, including motor stereotypes and mannerisms.

D.    The disturbance is not better accounted for by another specific 
           Pervasive Developmental Disorder or by Schizophrenia.

When Autism Strikes: Families Cope With Childhood Disintegrative Disorder By: Editor Catalano, Robert A.
General Health Encyclopedia
Yale Child Study Center
Yahoo! Groups: CDD


Landau-Kleffner syndrome (LKS), also called acquired epileptiform aphasia, is a rare, childhood neurological disorder characterized by the sudden or gradual development of aphasia (loss of language) and an abnormal electro-encephalogram (EEG). LKS affects the parts of the brain that control speech and comprehension. The disorder usually occurs in children between the ages of 3 and 7. Typically, these children develop normally and then, for no apparent reason, they lose the ability to understand others and to speak. While many of the affected individuals have seizures, some do not. The disorder is difficult to diagnose and may be misdiagnosed as autism, pervasive developmental disorder, hearing impairment, learning disability, auditory/verbal processing disorder, attention deficit disorder, mental retardation, childhood schizophrenia, or emotional/behavioral problems. For more links, click here.

What are the main symptoms?

All children with LKS have abnormal electrical activity in one, sometimes both temporal lobes, the area of the brain responsible among other functions for processing language. This epileptiform activity shows up in an EEG test particularly when the child is asleep.

About two-thirds of LKS children have seizures. Seizures during the night are common. Many children have very few seizures and these are readily controlled by anti-epileptic drugs. Some children never have obvious seizures: it is not necessary to have a seizure to have LKS. A few children have many seizures which are harder to control.

The language disorder in most children affects comprehension or understanding. Many LKS children become unable to understand their own name. They are also likely to have difficulty recognizing environmental sounds such as the telephone ringing. These children may appear to be deaf.

Expressive language - the ability to speak is often seriously affected; some children lose their speech completely. Rarely, a child may be able to understand language, but have difficulty with speaking.

Behavioural problems are common, especially hyper-activity, poor attention, depression and irritability.

Some children have episodes of very abnormal "autistic type behaviour" with symptoms such as avoidance of contact with family and friends (avoidance of eye contact is common) extreme pickiness over food, very disturbed sleep, attacks of rage and aggression, insensitivity to pain, bizarre and inappropriate and repetitive play.

There may be temporary other neurological problems such as loss of bladder and bowel control, episodes of visual disturbances may occur, the child can see but does not understand what he sees. He may have difficulty recognizing family and friends or common objects, such as food and clothes.

Landau-Kleffner Syndrome
FOLKS - Friends of Landau-Kleffner Syndrome
Epilepsy Ontario
Center for the Study of Autism (LKS)
NIDCD Health Information
QEEG in Landau-Kleffner Syndrome
Family Village
Yahoo! Groups: Rare Epilepsy Syndromes

23: July 24, 2002