Rett Syndrome Diagnostic Criteria
Rett syndrome is a pervasive developmental disorder such as Asperger’s disorder, childhood disintegrative disorder and autism. Pervasive developmental disorders are characterized by impairment in reciprocal social interaction skills, communication skills, or the presence of stereotyped behavior, interests, and activities (American Psychiatric Association, 2000). There are distinguishing characteristics that lead to the specific diagnosis of Rett syndrome.
The essential criteria identified in the American Psychiatric Association Diagnostic and Statistical Manual of Mental Disorders includes the development of multiple deficits following a period of seemingly normal functioning after birth. These normalities include an apparently normal prenatal and perinatal period with normal psychomotor development through the first five months of life with a normal head circumference at birth.
Rett syndrome diagnostic criteria include deceleration of head growth between the ages of five months and forty-eight months. Previously acquired hand movements are replaced with stereotyped gestures similar to wringing or washing of hands; this occurs between the ages of five months and thirty months. Additionally, there is a loss of social engagement early in the course of the syndrome.
People with Rett syndrome also appear to have a poorly coordinated gait or trunk movements. The final criterion for a Rett syndrome diagnosis is severely impaired expressive and receptive language development in combination with psychomotor retardation.
What the Criteria Look Like In Every Day Life
The National Institute of Child Health & Human Development (NICHD) highlights the loss of previously developed skills and abilities including speech, balance and coordination, purposeful hand movements and respiratory functioning (2006). Children stop talking even though they have spoken words before and may replace vocal outputs with sounds that do not have an obvious meaning. Breathing difficulties may include hyperventilation, breath-holding or apnea and air swallowing (Corcoran & Walsh, 2006).
It is important to note that problematic breathing associated with Rett syndrome only occurs while the person is awake, not asleep (NICHD, 2006). The ability to walk is often challenging and children with Rett syndrome appear to be clumsy. According to Kerr and colleagues (2003), 60% of those with the syndrome are able to walk later in life while others become unable to sit up or walk and may become immobile. Hands no longer function to grab or point and facial expressions or capabilities are hindered. Smiles fade and eyes no longer follow motion or others in the environment.
Common Symptoms Also Associated with Rett Syndrome
The National Institute of Child Health & Human Development has identified the following additional symptomology often associated with the diagnosis of Retts (2006). Seizures are a common problem which may involve whole body convulsions or staring spells without movement. Constipation, gastro-esophageal reflux or gall bladder problems including gallstones may be experienced. Some individuals have cardiac or heart problems such as irregular heart beats. Troublesome swallowing and inability to chew food properly may increase the challenge of receiving proper nourishment.
Problematic sleeping patterns may include disrupted sleeping at night during childhood and an increase in total and day time sleep after age five. NICHD claim that some researchers say problems with sleep is one of the earliest symptoms and it can appear as early as between one to two months of age (2006).
The impairments that Retts causes in daily life are often debilitating. Kerr and authors (2003), said that 80% of girls with Rett syndrome have scoliosis, some so severely that they require surgery. These symptoms are not required for diagnosis, but understanding the possible relation or cause may be a supportive finding for the individual and their family.
Distinguishing Rett Syndrome from other Pervasive Development Disorders
Defining characteristics of Retts according to the American Psychiatric Association include it typically being associated with severe or profound mental retardation; and the pattern of developmental regression is highly distinctive with its onset commonly in the first or second year of life.
Developmental regression may occur during normal development but it is not prolonged. Regression in functioning due to childhood disintegrative disorder occurs after a period of at least two years, while regression can occur as early as five months with Rett syndrome.
Common symptomology can make the diagnostic process confusing. Corcoran and Walsh (2006) said that there is the potential for confusion with autism during preschool years because of stereotyped movements and deteriorating language, social and motor skills but that by school age these features are less prominent in individuals with Retts.
Other autistic like symptoms sometimes experienced by those with Rett syndrome include a lack of interest in their surroundings, anxiety in new environments, problematic social behaviors and a lack of eye contact. The timing and longevity of symptoms is important to document in order to properly diagnose.
American Psychiatric Association (2000). Diagnostic and statistical manual of mental disorders, 4th edition, (DSM-IV-TR). Washington, DC: American Psychiatric Association.
Corcoran, J. & Walsh, J. (2006). Clinical assessment and diagnosis in social work practice. New York: Oxford University Press.
Kerr, A. M., Webb, P., Prescott, R.J., & Milne, Y. (2003). Results of surgery for scoliosis in Rett syndrome. Journal of Child Neurology, 18, 703-708.
National Institute of Child Health & Human Development (NICHD). (2006). Rett syndrome.