Developmental Disabilities

Asperger’s disorder is a lifelong developmental condition, characterized by a severe and sustained impairment in social interaction and the development of restricted, repetitive patterns of behaviour, interests and activities. Such characteristics are comparable to those of a child with autism.

In contrast to autism, however, the individual with Asperger’s disorder will experience no significant delays in acquisition of language, adaptive behaviour (other than social interaction), cognitive development, and development of age appropriate self-help skill, or in curiosity about the environment.

An individual with Asperger’s disorder will display a lack of sensitivity, intuition and normal human understanding.The individual will appear to live in the normal world but in a way that is uniquely his/her own. The individual’s speech, for example, is more a proclaiming than a two-way communication.

Asperger’s disorder appears to have a somewhat later onset that autistic disorder, or at least to be recognized somewhat later. Motor delays or motor clumsiness may be noted in the preschool period. Difficulties in empathy and modulation of school interaction may become more apparent in the context of school.

Associated Links

Online Asperger’s Syndrome Information & Support
Asperger’s Disorder Homepage


Autism is a lifelong developmental condition that is treatable in varying degrees with early diagnosis and intervention. Autism is caused by an underlying physical dysfunction within the brain or central nervous system, the exact nature of which is yet unknown.

Autism is four times more common in boys than girls and occurs in all races and social and psychological backgrounds. It is usually diagnosed in preschool years and may be confused with mental disability, deafness, epilepsy and/or other disorders.

The chief difficulty for a child with autism seems to lie with processing information. Abnormal responses to sensations as well as hearing irregularities may trigger unusual behaviours. It may require extreme efforts to make sense of a world that is not understood, to seek structure and routine in the midst of a confusing muddle. If the individual experiences confusion, the result may be withdrawal or an emotional outburst.

There are no current test for autism; diagnosis is based on observation of behavior.

Associated Links

Autism BC
Canucks Autism Network


Down syndrome is a genetic defect causing limitations in physical cognitive development. It is the result of a chromosomal error. One in every 700-800 live births will be effected by Down syndrome.

Recent studies show that, thought all children with Down syndrome have some degree of intellectual disability, other factors such as environment, misinformation and low expectations impact on their learning potential.

Associated Links

National Association for Down Syndrome
National Down Syndrome Society
The Canadian Down Syndrome Society of BC


Mentally Handicapped / Developmental Disabilities

A mental handicap/developmental disabilities usually results from developmental abnormalities of the brain occurring any time from conception to age 18. A mental handicap often occurs because certain brain structures either did not develop, developed improperly, or were injured or damaged.

Having a mental handicap can cause difficulties in areas of:

  • Motor coordination
  • Speech development
  • Social behaviour
  • Habit training
  • Learning ability

There are over 200 causes of an individual to become developmentally delayed: genetic problems such as Down Syndrome, pregnancy difficulties, birth difficulties or problems with the environment after birth.


People with IQ’s ranging from 80 – 130 are considered to have normal intelligence. An IQ of about 70 -80 is regarded as demonstrating a borderline degree of intellectual impairmentChildren and adults with IQ scores below 70 are regarded as having an intellectual disability. Other terms synonymous with this disability are “mentally handicapped”, “mentally retarded”, “developmentally disabled”, and “intellectually challenged”.

The following level are often used to describe the level of competence of such individuals:

  • Mild intellectual disability (IQ range from about 50 to 70). Adults with this degree of disability can usually live independently with little supervision.
  • Moderate intellectual disability (IQ range from about 35 to 50). Adults with this degree of disability will require some supervision with day-to-day activities such as shopping, cooking, and commuting.
  • Severe intellectual disability (IQ range from about 20 to 35). Adults with this degree of disability will require a great deal of supervision.
  • Profound intellectual disability(IQ range below 20).

Associated Links

American Association of Intellectual and Developmental Disabilities


Prader-Willi Syndrome (PWS) is an uncommon, noninherited birth defect, lifelong and life-threatening, affecting all races and both sexes. Prevalence is estimated to be 1:12,000 to 15,000. Its characteristics include hypotonia, insatiable appetite, obesity if food intake is uncontrolled, hypogonadism and incomplete sexual development, developmental delays, variable degrees of mental retardation or functional retardation, short stature (adult), small hands and feet, mild dysmorphology, and behavior problems which can be severe.

The cause of this condition is unclear. Approximately 70% have an interstitial deletion or other abnormal finding on chromosome 15, using high resolution (prometaphase) analysis. The remainder have two maternal chromosome 15s and no paternal 15 (maternal uniparental disomy). Diagnosis of infants with PWS is difficult. Newborns are hypotonic, lethargic, exhibit genital hypoplasia, and often require gavage or other special feeding techniques. Prenatally, fetal movement is decreased. Diagnosis in adults is more certain if classic characteristics are present: short stature, small hands and feet, CNS dysfunction, underdeveloped sexual characteristics, poor large muscle strength.

Motor development is delayed typically one to two years, as are most milestones. For example, walking usually occurs around age two. Poor gross motor performance and balance improve slowly and lag behind normal individuals of the same age. Speech and language problems are common. Cause is unclear, possibly poor muscle tone affecting vocal muscles and/or decreased saliva production. Speech therapy is recommended to relieve frustration associated with non-communication. Though language development is delayed, verbal ability is often a strength. Articulation may remain poor. The average IQ is around 70, with a range from 40 to 105. Typically, functioning is below IQ level. Abstract thinking and concepts are weaknesses. Even with a lower IQ, cleverness in food seeking can exist.

Behavior problems, ranging from stubbornness to violent temper tantrums and increasing with age, usually begin to appear during the preschool years when most are pleasant and cooperative. Intervention therapy can be used to modify severity (e.g., fluexitine serotonin uptake inhibitors have been particularly beneficial in some cases). True depression and psychotic episodes are reported.

Compulsive eating and obsession with food begin usually between the ages of 2 – 4, though they may start later. Some learn to eat at fixed times and may refuse certain foods, but the insatiable drive for food persists. Sneaking or stealing extra food is common. In most situations, all sources of food must be kept under lock and key. Avoidance of temptation is helpful. Obesity occurs in 95% if there are no environmental controls. An increasing number are being diagnosed before onset of obesity. Whether obese at diagnosis or not, more and more have their weight managed within acceptable levels. Calorie utilization is decreased and diets should offer fewer calories than unual (often 1,000-1,200 per day). Exercise is critical to weight control.

Associated Links

Prader-Willi Association (USA)
Prader-Willi Syndrome Association (UK)


Williams syndrome is a rare genetic condition (estimated to occur in 1/20,000 births) that causes medical and developmental problems. It was first recognized as a distinct entity in 1961. It is present at birth, and affects males and females equally. It can occur in all ethnic groups and has been identified in countries throughout the world.

Williams syndrome is not caused by anything the parents did or did not do either before or during pregnancy. We know that most individuals with Williams syndrome are missing genetic material on chromosome #7 including the gene that makes the protein elastin (a protein which provides strength and elasticity to vessel walls.) It is likely that the elastin gene deletion accounts for many of the physical features of Williams syndrome. Some medical and developmental problems are probably caused by deletions of additional genetic material near the elastin gene on chromosome #7. The extent of these deletions may vary among individuals. In most families the child with Williams syndrome is the only one to have the condition in his or her entire extended family. However, the individual with Williams syndrome has a 50% chance of passing the disorder on to each of his or her children.

Individuals with Williams syndrome have a very endearing personality. They have a unique strength in their expressive language skills, and are extremely polite. They are typically unafraid of strangers and show a greater interest in contact with adults than with their peers.

Most people with Williams syndrome have some degree of intellectual handicap. Young children with Williams syndrome often experience developmental delays; milestones such as walking, talking and toilet training are often achieved somewhat later than is considered normal. Distractibility is a common problem in mid-childhood, which appears to get better as the children get older.

Older children and adults with Williams syndrome often demonstrate intellectual “strengths and weaknesses.” There are some intellectual areas (such as speech, long term memory, and social skills) in which performance is quite strong, while other intellectual areas (such as fine motor and spatial relations) are significantly deficient.

The vast majority of adults with Williams syndrome master self-help skills and complete academic and/or vocational school. They are employed in a variety of settings (ranging from supervised to independent jobs). Many adults with Williams syndrome live with their parents; others live in supervised apartments and some are able to live on their own.

Associated Links

Williams Syndrome Foundation (UK)
Williams Syndrome Association

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