The document discusses the history and definitions of intellectual disability/mental retardation. It covers terms that were previously used like "idiot" and "moron" and explains newer terms like "intellectual disability." Causes include genetic/chromosomal factors as well as environmental influences. Characteristics of intellectual disability can include difficulties with learning, social skills, adaptive behaviors, attention, memory, and speech/language. The document outlines assessment methods and teaching strategies for students with intellectual disabilities. It also describes several specific genetic syndromes associated with intellectual disability like Down syndrome, fragile X syndrome, and phenylketonuria.

1. Intellectual Disability
Englevert Reyes, M. Ed.

2. What’s in a Name?
• Idiot
• Moron
• Feeble Minded
• Mentally Retarded
• Intellectual Disability
• AAMR
– American Association on Intellectual and
Developmental Disabilities (AAIDD)

3. Taylor/Smiley/Richards,
Exceptional Students
What is the History of
Mental Retardation/Intellectual
Disabilities?
• Early History
– Rejection and isolation
• 20th Century
– Hospitals and institutions were provided.
– Eugenics movement
– Rise of advocacy organizations and court challenges
– Passage of IDEA in 1975

4. Taylor/Smiley/Richards,
Exceptional Students
Why the Use of Two Terms?
• Mental Retardation vs. Intellectual
Disabilities
– Negative connotations for MR, but used in
IDEA 04
– ID is less stigmatizing, but may be a less clear
term than MR

5. What is Mental Retardation
• An individual is considered to have
mental retardation if:
– Intellectual functioning IQ <70
– Significant limitations in tow or more
adaptive skill areas
– Present from childhood

6. IDEA Definition
“Mental retardation means significantly
subaverage general intellectual
functioning existing concurrently with
deficits in adaptive behavior and
manifested during the developmental
period, that adversely affects a child’s
educational performance.”

7. AAMR 2002 Definition
“Mental retardation is a disability
characterized by significant limitations
both in intellectual functioning and in
adaptive behavior as expressed in
conceptual, social, and practical adaptive
skills. This disability originates before
age 18.”

9. ICD-10
• Tenth revision of the International
Classification of Diseases from the World
Health Organization
• Characterizes MR as a condition resulting
from a failure of the mind to develop
• Four levels

12. What are adaptive skills?
Adaptive skill areas are those daily living
skills needed to live, work and play in the
community

13. Adaptive Skill Areas
• Communication
• Self-care
• Home living
• Social skills
• Leisure
• Health & safety
• Self-direction
• Functional academics
• Community use
• Work

15. Mild Mental Retardation
• Previously referred to as “educable”
• Largest segment of those with MR (85%)
• Typically develop social/communication
skills during preschool years, minimal
impairment in sensorimotor areas, often
indistinguishable from “typicals” until
later age
• By late teens acquire skills up to
approximately the 6th grade level

16. Moderate Mental Retardation
• Previously referred to as “trainable”
• About 10% of those with MR
• Most acquire communication skills during early
childhood years
• Generally benefit from social/vocational training and
with moderate supervision can attend to personal care
• Difficulties recognizing social conventions which
interferes with peer relations in adolescence
• Unlikely to progress beyond the 2nd grade academically
• Often adapt well to life in the community in supervised
settings (performing unskilled or semiskilled work)

17. Severe Mental Retardation
• 3 – 4% of those with MR
• Acquire little or no communicative speech in
childhood; may learn to talk by school age
and be trained in elementary self-care skills
• Can master sight reading “survival” words
• Able to perform simple tasks as adults in
closely supervised settings
• Most adapt well to life in the community,
living in group homes or with families

18. Profound Mental Retardation
• 1 – 2% of those with MR
• Most have an identifiable neurological
condition that accounts for their MR
• Considerable impairments in
sensorimotor functioning
• Optimal development may occur in a
highly structured environment with
constant aid

19. Prevalence
• 1% (1 – 3% in developed countries)
• The prevalence of MR due to biological
factors is similar among children of all SES;
however, certain etiological factors are linked
to lower SES (e.g., lead poisoning &
premature birth)
• More common among males (1.5:1)
• In cases without a specifically identified
biological cause, the MR is usually milder;
and individuals from lower SES are over-
represented

20. Taylor/Smiley/Richards,
Exceptional Students
What are the Causes of
Intellectual Disabilities?
• Genetic and Chromosomal – Examples
include:
– Tuberous Sclerosis, Neurofibromatosis,
PKU, Galactosemia, Hurler Syndrome, Tay
Sachs, Hunter Syndrome, Lesch-Nyan
Syndrome, Fragile X, Rett Syndrome, Down
Syndrome

21. Taylor/Smiley/Richards,
Exceptional Students
What are the Causes of
Intellectual Disabilities?
• Environmental – Examples include:
– Toxoplasmosis, Rubella, Cytomegalovirus,
Radiation, Malnutrition, Maternal Age,
Maternal Health, Drug and Substance Abuse,
Blood Type Incompatibility
• Psychosocial Factors – Examples include:
– Poverty, Malnutrition, Inadequate Health Care
• May contribute to mental retardation rather than
be a direct cause

22. Prevention
• Prenatal care
• Newborn screening
• Vaccines
• Lead removal
• Child safety

23. Taylor/Smiley/Richards,
Exceptional Students
What are Possible Characteristics of
Students with Intellectual Disabilities?
• Difficulties learning
• Deficits in social-personal skills
• Deficits in adaptive behavior skills
• Attention difficulties
• Memory deficits
• Difficulty transferring and generalizing skills
• Speech and Language delays

24. Taylor/Smiley/Richards,
Exceptional Students
How are Students with
Mental Retardation Identified?
• Intelligence Testing (IQ below 70-75)
• Adaptive Skills Assessments (deficits in
adaptive skills)
• Academic Skills Assessments (adversely
affects educational performance)

25. Taylor/Smiley/Richards,
Exceptional Students
What Do I Teach Students with
Intellectual Disabilities?
• Person-centered planning
• Basic academic skills
• Functional curriculum
– Functional academics, independent life
skills, self-determination, self-advocacy
• Community-based instruction
• Transition planning

26. Taylor/Smiley/Richards,
Exceptional Students
How Do I Teach Students with
Intellectual Disabilities?
• Direct instruction with clear objectives,
advance organizers, “think-aloud”
model, guided practice, independent
practice, post-organizers
– Focus on task analysis
– Focus on sequencing tasks for recognition,
recall, reconstruction
– Focus on presentation and practice, including
use of prompts
• Generalization

27. Down Syndrome (trisomy 21
syndrome)
• Down syndrome has been the most investigated,
and most discussed syndrome in mental
retardation.
• Children with this syndrome were originally
called mongoloid because of their physical
characteristics of slanted eyes, epicanthal folds,
and flat nose.
• Despite a plethora of theories and hypotheses
advanced in the past 100 years, the cause of
Down syndrome is still unknown.

28. A. A young child with Down syndrome. B. A
young adult with fragile X syndrome.

29. Fragile X Syndrome
• Fragile X syndrome is the second most common
single cause of mental retardation.
• The syndrome results from a mutation on the X
chromosome at what is known as the fragile site
(Xq27.3).
• The typical phenotype includes a large, long
head and ears, short stature, hyperextensible
joints, and postpubertal macroorchidism.
• The mental retardation ranges from mild to
severe.

30. Martin-Bell
syndrome
Fragile X syndrome is believed to
occur in about 1 of every 1,000
males and 1 of every 2,000
females.

31. Fragile X Syndrome

32. Prader-Willi Syndrome
• Prader-Willi syndrome is postulated to result
from a small deletion involving chromosome
15, usually occurring sporadically.
• Its prevalence is less than 1 of 10,000.
• Persons with the syndrome exhibit
compulsive eating behavior and often obesity,
mental retardation, hypogonadism, small
stature, hypotonia, and small hands and feet.
• Children with the syndrome often have
oppositional and defiant behavior.

33. Prader-Willi Syndrome

34. Cat's Cry (Cri-du-Chat)
Syndrome
• Children with cat's cry syndrome lack part of
chromosome 5.
• They are severely retarded and
show many signs often associated with
chromosomal aberrations, such as
microcephaly, low-set ears, oblique palpebral
fissures, hypertelorism, and micrognathia.
• The characteristic cat-like cry caused by
laryngeal abnormalities that gave the
syndrome its name gradually changes and
disappears with increasing age.

35. Cri-du-Chat Syndrome

36. Cri-du-Chat Syndrome

37. Phenylketonuria
• PKU was first described by Ivar Asbjörn Fölling
in 1934 as the paradigmatic inborn error of
metabolism. PKU is transmitted as a simple
recessive autosomal mendelian trait and occurs
in about 1 of every 10,000 to 15,000 live births.
• The basic metabolic defect in PKU is an inability
to convert phenylalanine, an essential amino
acid, to paratyrosine because of the absence or
inactivity of the liver enzyme phenylalanine
hydroxylase, which catalyzes the conversion.

39. Phenylketonuria
• Most patients with PKU are severely retarded, but
some are reported to have borderline or normal
intelligence. Eczema, vomiting, and convulsions
occur in about a third of all patients.
• They frequently have temper tantrums and often
display bizarre movements of their bodies and
upper extremities, including twisting hand
mannerisms; their behavior sometimes
resembles that of children with autism or
schizophrenia.

41. Rett's Disorder
• Rett's disorder is hypothesized to be an X-
linked dominant mental retardation
syndrome that is degenerative and affects
only females.
• Deterioration in communications skills, motor
behavior, and social functioning starts at
about 1 year of age. Autistic-like symptoms
are common, as are ataxia, facial grimacing,
teeth-grinding, and loss of speech.

42. Rett's Disorder

43. Neurofibromatosis
• Also called von Recklinghausen's disease,
neurofibromatosis is the most common of the
neurocutaneous syndromes caused by a single
dominant gene, which may be inherited or be
a new mutation. The disorder occurs in about
1 of 5,000 births. and is characterized by cafe
au lait spots on the skin and by neurofibromas,
including optic gliomas and acoustic
neuromas, caused by abnormal cell migration.
• Mild mental retardation occurs in up to one
third of those with the disease.

45. Tuberous Sclerosis
• Tuberous sclerosis is the second most
common of the neurocutaneous
syndromes; a progressive mental
retardation occurs in up to two thirds of
all affected persons.
• It occurs in about 1 of 15,000 persons
and is inherited by autosomal dominant
transmission.

46. Tuberous Sclerosis

47. Lesch-Nyhan Syndrome
• Lesch-Nyhan syndrome is a rare disorder
caused by a deficiency of an enzyme
involved in purine metabolism.
• The disorder is X-linked; patients have
mental retardation, microcephaly,
seizures, choreoathetosis, and spasticity.

48. Lesch-Nyhan
Syndrome

49. Adrenoleukodystrophy
• The most common of several disorders of
sudanophilic cerebral sclerosis,
adrenoleukodystrophy is characterized by diffuse
demyelination of the cerebral white matter
resulting in visual and intellectual impairment,
seizures, spasticity, and progression to death.
• The disorder is transmitted by a sex-linked gene
located on the distal end of the long arm of the X
chromosome.
• The clinical onset is generally between 5 and 8
years of age, with early seizures, disturbances in
gait, and mild intellectual impairment.

50. Adrenoleukodystrophy
• The story of a child
with the disorder was
presented in the 1992
film Lorenzo's Oil.

51. Maple Syrup Urine Disease
• An inborn error of metabolism caused by
defective oxidative decarboxylation of )-keto
acids of leucine, isoleucine, and valine.
• These branched-chain amino acids are present
in the blood and urine in high concentrations.
• Manifestations of disease include feeding
difficulties, physical and mental retardation,
and a urine odor similar to that of maple syrup;
neonatal death is common.

52. Fetal Alcohol Syndrome
• A typical phenotypic picture of facial
dysmorphism that includes
hypertelorism, microcephaly, short
palpebral fissures, inner epicanthal
folds, and a short, turned-up nose.
• The entire syndrome occurs in up to
15 percent of babies born to women
who regularly ingest large amounts
of alcohol.