Chapter 5 Summary
Learners with Intellectual Disabilities
. Once diagnosed as intellectually disabled a . A person’s level of mental function does not
oerson remains within this classification for life necessarily remain stable. With intensive
educational programming a person can improve to
the point they are no long intellectually disabled.
. Professionals are in agreement about the . There is disagreement about definition,
definition of intellectual disabilities classification, and terminology about “intellectual
disabilities. Some proposed throwing away the
. It is easy to identify the cause of intellectual . Human genome mapping has increased our
disabilities knowledge of intellectual disabilities. Although it is
difficult to pinpoint the cause of these disabilities,
especially in those with only mild ones.
. Psychosocial factors are the cause of the vast . Exact % is not available. Researchers are finding
majority of cases of mild intellectual disabilities more genetic syndromes and some hereditary
factors involved in mild intellectual disabilities.
. When workers with intellectual disabilities fail on . failure on the job is more likely because poor job
the job, it is usually because they do not have responsibility (attendance & lack of initiative),
adequate job skills. social competence – resulting in incompetence in
. People with intellectual disabilities should not be . Increasingly more people with intellectual
expected to work in the competitive job market disabilities hold jobs in competitive employment.
Can be helped through supportive employment
situations – job coach helps them and their
employer adapt to a new workplace.
- Much of the success achieved by people with intellectually disabilities is attributed to a change
in philosophy – includes respecting the rights to be a part of decisions affecting their lives and
involves the use of natural supports.
- Natural Supports: resources in a person’s environment that can be used for support, such as
friends, family and co workers.
- There is now a reluctance attitude from professionals to label someone as having an intellectual
1) Professionals became concerned about the misdiagnosis of children from ethnic minority
groups as intellectually disabled
2) Some believe that the diagnosis of intellectual disability results in a stigma that causes
children to have poor self-concepts and be viewed negatively by others
3) Some professionals believe intellectually disability is a socially constructed condition
- In Canada “mentally retarded” was once used to describe those with an intellectual disability.
American Association on Intellectual and Developmental Disabilities have removed the label of
mental retardation. Adaptive Behaviour
- Used to be common practice to diagnose intellectually disabled based on IQ scores.
- Professionals now look at IQ tests along with adaptive behavior now – some students may
present poor IQ scores but be “streetwise”
Adaptive Behaviour: the collection of conceptual, social and practical skills that people have learned
so that they can in their every day lives.
- Examples of the (3) skills; conceptual skills, social skills, practical skills
Conceptual Skills Social Skills Practical Skills
.Receptive and expressive . Interpersonal . Personal acitivities of daily
language . Responsibilitiy life: eating, dressing, mobility,
.Reading writing . Self-Esteem toileting
. Money concepts .Gulibility . Intrumental activities of daily
. Self direction . Naivete life: preparing meals, taking
. Follows rules medication, using the phone,
. Obeys rules managing money, using
. Avoids victimization transportation, doing
. Occupational skills
. Maintaining a safe
Improvement of Intellectual Disabilities
- Intellectual disabilities can be improves – is directly related to the amount of support an
individual receives from the environment
- Natural supports – those that typically occur in one’s own environment (friends, family)
- Service-based supports – those provided by professionals (teachers, counselors, psychologists)
Levels of support: the basis of the AAMR classification scheme; characterizes the amount of support
needed for someone with intellectual disabilities to function a competently as possible.
- The 4 levels of support:
. Intermittent – supports an as-needed basis, short term or episodic nature. The person does not
always need the support. Supports may be high or low intensity
. Limited – intensity of support is characterized by contency over time, time-limited (not as short
as intermittent), may require fewer staff members and less costly
. Extensive – support with regular involvement (daily), in some environments (school, work or
home) is not time limited(ex: long-term support/ long –term home living support)
. Pervasive: characterized by constancy, high intensity, provision across environments, life
sustaining nature. Involves more staff members, time-limited supports. Causes
- A common way to categorize causes of intellectual disabilities is according to the time the cause
occurs : prenatal (before birth), perinatal (at the time of birth), and postnatal (after birth)
- Can be grouped into (4) different causes:
1) Chromosomal disorders: any of several syndromes resulting from abnormal or damaged
2) Inborn errors of metabolism
3) Developmental disorders affecting brain formation
4) Environmental influences
Chromosomal Disorders – ( most common genetic syndromes; down syndrome, Williams
syndrome, fragile X syndrome, and prader-willi syndrome.)
. Down Syndome: a condition resulting from an abnormality with the 21 pair of chromosomes; is a
triplet rather than a pair – referred to as trisomy 21.
. it is the most common intellectual disabilities that is present at birth
. characterizations: thick epicanthal fold in the corners of the eyes, make eyes appear to
slant upwards slightly, small stature, decrease muscle tone, hyperflexibility of joints, a
small oral cavity that can result in a protruding tongue, short broad hangs with a single
palmar crease, heart defects, and vulnerability to upper respiratory infections
. degree of the intellectual disability varies; most fall in moderate rang, with intensive
special ed programming many have achievered mildly intellectually disabled ranges
. likelihood of having a child with down syndrome increased with the age of the mother
(1 in 30 chance for mothers who are 45 yrs of age). Other causes: age of the father,
exposure to radiation, exposure to some viruses.
. Methods for screening down synodrome:
. Amniocentesis: the physician takes a sample of amniotic fluid from the sac
around the fetus and analyzes fetal cells for chromosomal abnormalities. Can
also test proteins that may have leaked from the fetus’ spinal column (ex: spina
bifida – condition resulting from failure of the spine to close completely during
. Chronionic villus sampling (CVS): used to test unborn fetus for variety of
chromosomal abnormalities. Small amount of tissue is removed from the
chorion (a membrane that will eventually help form the placenta),and tested.
Can be done before amniocentesis – but if so the risk of miscarriage is higher. . Nuchal translucency sonogram: fluid behind the fetus’s neck and the mother’s
blood are analyzed
. Maternal Serum screening (MSS): blood sample is taken from the mother and
is analyzed. If the results are positive a more accurate test such as
amniocentesis or CVS is usually recommended
. Williams Syndrome
. caused by the absence of material on the 7 pair of chromosomes.
. the IQ range of those with this syndrome is 40 to 70 – results in intellectual disabilities, heart
defects and elfin facial features
. Have an unusual sensitivity to sounds, and display strengths in spoken language and sociability
. Have severe deficits in spatial organization, reading, writing and math
. Fragile X Syndrome
. One of the most common known hereditary causes of intellectual disabilities (more known in
boys than girls)
. Occurs less often in females because they have XX chromosomes, giving them more protection
if one of their chromosomes is damaged
. A condition in which the bottom of the X chromosome in the 23 pair of chromosomes is
. Physical features: large head, large and flat ears, a long narrow face, a prominent forehead, a
broad nose, prominent square chin, large testicles, large hands with nontapering fingers.
. Some have less severe cognitive deficiencies (especially females - scoring in the normal range
. Prader-Willi Syndrome
. Caused by inheriting their father a lack of genetic material on the 15 pair of chromosomes.
. Two distinct phases:
(1) Infants are lethargic and have difficultly eating, (2) at 1 yr they become obsessed with food
. most serious medical problem is vulnerability to obesity.
. other health problems: short stature (to growth hormone deficiencies), heart defects,
sleep disturbances, daytime drowsiness sleep apnea (cessation of breathing while sleeping,
and scoliosis (curvature of spine) . Most are mildly intellectually disabled, some have IQs in a normal range
Inborn Error of Metabolism
- Result from deficiencies in enzymes used to metabolize basic substances in the body, such a
amino acids, carbohydrates, vitamins or trace elements
- One of the most common is phenlylketornuria (PKU_ - the inability of the body to convert a
common dietary substance phenylalanine to tyrosine, which results in abnormal brain
- Babies are routinely screened for PKU before leaving the hospital and are put on a special diet
- The diet was once said to be discontinued in middle childhood – authorities now recommend
the diet be continues indefinitely because: 1) those who stop the diet are at risk for developing
learning disabilities and other problems, 90% of babies born to mothers of PKU (who are not
longer on the diet) will have intellectual disabilities and heart defects
Developmental Disorders of Brain Formation
- Microcephalus – the head is abnormally small, and conical in shape.
. Intellectual disabilities: range from severe to profound
. No special treatment, life expectancy is short
- Hydrocephalus – results from the accumulation of cebrosprinal fluid inside or outside of the
. The blockage of the fluid circulation – results in buildup of excessive pressure on the brain and
the enlargement of the skill
. Intellectual disabilities: degree depends on how early the condition is diagnosed and treated
. Two treatments: 1) surgical placement of a shunt (tube) that drains the excess fluid away from
the brain to the abdomen, 2) insertion of a device that caused the fluid to bypass the obstructed
Environmental Influences (ex: alcohol, maternal malnutrition)
- Fetal Alcohol syndrome disorder (FASD) (range from mild to severe)– significant health
problem for unborn children of expectant mothers who consume large quantities of alcohol
. Used as an umbrella term for disabilities cause by drinking alcohol during pregnancy:
. Fetal Alcohol Syndrome
. Partial Fetal Alcohol Syndrome (pFAS): abnormalities more subtle than those of FAS
. Alcohol-Related Neurodevelopment Disorder (ARND)
. Alcohol-Related Birth Defects (ARBD)
- FAS is characterized by physical deformities, intellectual disabilities and behavioural
The Human Genome Project box pg. 112 Down Syndrome and Alzheimer’s Disease pg. 113
Rubella (German measles) – a serious viral disease, if it occurs the first trimester(3 weeks) it may cuase
serious birth defects in the fetus.
- Problem that can happen during the process of giving birth – problems could result in brain
injury and intellectual disabilities (ex: if the child is not positioned properly in the uterus)
. Anoxia: from difficulty during deliver, is deprivation of oxygen causing brain injury
. Low birth weight (LBW): babies who are born weighing less than 2.5 kilograms. At risk for
behavioural and medical conditions such as intellectual disabilities. This is more common for
mothers living in poverty
. Infections like syphilis and herpes simplex can be passed from the mother to the child during
- Biological Postnatal Causes:
- Examples: traumatic brain injury (TBI), infections, malnutrition, and toxins.
- Traumatic brain injury: injury to the brain resulting in total or partial disability or psychosocial
maladjustment that affects educational performance; may affect cognition, language, memory,
reasoning, abstract thinking, judgment, problem solving, sensory or perceptual and motor
abilities, psychosocial behavior, physical functions information processing, or speech.
. can result from blows to the head, vechicular accidents and violent shaking
. (not including conditions present at bitch, with trauma or degenerative diseases or conditions)
- Meningitis: a bacterial or viral infection of the lining of the brain or spinal cord; can cause a
number of exceptionalities