Presentation about the definition and causes of Mental Retardation or Intellectual Disability for Special Education subject.

1. Mental
Retardation/Intellectual
Disability:
Definition and its causes
Presented by:
Mirasol S. Madrid
III-9 BS Psychology

2. What is Mental
Retardation/
Intellectual
disability?

3. Mental Retardation
“Mental retardation refers to substantial limitations in
present functioning. It is characterized by significantly
sub-average intellectual functioning, existing
concurrently with related limitations in two or more of
the following adaptive skills areas: communication,
self-care, home living, social skills, community use,
self-direction, health and safety, functional academics,
leisure and work. Mental retardation manifests before
age 18.” (Heward, 2003)

4. Mental Retardation
• Substantial limitations in present
functioning means that the person has
difficulty in performing everyday activities
related to taking care of one’s self,
ordinary tasks at home and work related
to other adaptive skills areas. Academic
work is also included, if the person goes
to school.

5. Mental Retardation
• Significantly sub-average intellectual
functioning means that the person has
significantly below average intelligence.
The person has difficulty to learn, solve
problems, accumulate knowledge and
adapt to new situations. However, sub-
average intellectual functioning can
change.

6. Mental Retardation
• Limitations in the adaptive skills or
behavior means that the person with
mental retardation fail to meet the
standards of personal independence and
social responsibility expected of their
chronological age and cultural group.
Adaptive skills are assessed by means of
standardized adaptive behavior scales.

7. Mental Retardation
• Related limitations in the adaptive
skills areas means that the person has
difficulty in performing the following tasks:
communication, self-care, home living,
community use, social skills, self-direction,
health and safety, functional academics,
leisure and work.

8. Mental Retardation
• Mental Retardation is a developmental
disability.
• NOTE: It is important that the person must
meet all three of the above criteria. Thus,
an IQ score below 70 or 75 is not
sufficient to classify a person as with
mental retardation.

9. INTELLECTUAL
DISABILITY
Mentally deficient

10. What are the
classifications
of Mental
Retardation?

11. Classification of Mental Retardation
In the previous American Association on
Mental Retardation classification system, there are
four levels that are still widely used today (based
on IQ score):
Classification IQ Score
MILD MR 55-70
MODERATE MR 40-54
SEVERE MR 25-39
PROFOUND MR Below 25

12. Classification of Mental Retardation
In the previous American Association on
Mental Retardation classification system, there are
four levels that are still widely used today (based
on IQ score):
Classification IQ Score
MILD MR
- Educable (6th grade)
- May live independently,
with community and
social support
55-70

13. Classification of Mental Retardation
Classification IQ Score
MODERATE MR
- Trainable (work and self-
care task)
- Acquires communication
skills
- May live and function
successfully within the
community
40-54

14. Classification of Mental Retardation
Classification IQ Score
SEVERE MR
- They may master very
basic self-care skills and
some communication
skills
25-39
PROFOUND MR
- May develop basic self-
care skills and
communication skills
- Needs high supervision
Below 25

15. Classification of Mental Retardation
However, the AAMR has introduced a
new system of classification that is based on
the amount of support that the person needs
in order to function to the highest possible
level The four categories of mental
retardation according to the intensity of
needed supports are: (Wehmeyer, 2002)

16. Classification of Mental Retardation
Classification Support Needed
Intermittent
Support
are on “as needed” basis,
that is, the person needs
help only at certain
periods of time and not all
the time. Support will most
likely be required during
periods of transition. (e.g.
moving from school to
work.)

17. Classification of Mental Retardation
Classification Support Needed
Limited Supports
are required
consistently, though not
on a daily basis. The
support needed is of
non-intensive nature.

18. Classification of Mental Retardation
Classification Support Needed
Extensive Supports
are needed on a regular
basis; daily supports are
required in some
environments, for
example, daily home
living tasks.

19. Classification of Mental Retardation
Classification Support Needed
Pervasive Supports
are daily extensive
supports, perhaps of a
life-sustaining nature
required in multiple
environments.

20. What are the
causes of MR?

21. Causes of Mental Retardation
There are more than 250 identified
causes of mental retardation. The AAMR
classifies the causes or etiological factors
based on: Time of onset
A. Prenatal or Biological (before birth)
B. Perinatal (during birth)
C. Postnatal and Environmental (after birth)

22. Causes of Mental Retardation
A. Prenatal or Biological (before birth)
Prenatal causes are those that
originate during conception or pregnancy
until before birth are chromosomal
disorders such as trisomy 21 or Down
Syndrome, Klinefelter syndrome, Fragile X
syndrome, Prader-Willi syndrome,
Phenylketonuria, and William Syndrome.

23. Causes of Mental Retardation
Chromosomal Disorder Cause Characteristics
• Down Syndrome
 Was named after Dr.
Langdon Down
 the best known and
well researched
biological condition
associated with MR
 affects 1 in 1,000 live
births
 Chromosomal
abnormality
 Trisomy 21 – the 21st
set is a triplet rather
than a pair which
often results in the
moderate level of MR
 Correlated with the
age of the mother
 can also be a result of
a nondisjunction of
the father’s
chromosome 21
 Flat, broad face
 Small ears and nose
 Upward slanting eyes
 Small mouth with
short roof
 Protruding tongue
 Hypertonia or floppy
muscles
 Shorter life span
 Sexually
underdeveloped
 sterile

25. Causes of Mental Retardation
Chromosomal Disorder Cause Characteristics
• Klinefelter
Syndrome
 More associated with
learning disability
 Males are commonly
affected
 Extra X chromosome
resulting to: XXY
 XXY is usually caused
by what is called
nondisjunction.
Nondisjunction
happens when a pair
of sex chromosomes
fails to separate
during egg (or sperm)
formation.
 Male sex organs are
underdeveloped:
unusually small
testicles
 Sterile
 Has female secondary
sex characteristics:
breast enlargement
and other feminine
characteristics
 Less-muscular bodies
 Wider hips, low
growth of facial hair

27. Causes of Mental Retardation
Chromosomal Disorder Cause Characteristics
• Fragile X Syndrome
 Most common MR
next to DS
 Occurs in both gender
but males are mostly
affected
 Majority of males
experience mild to
moderate MR
(childhood) and
moderate to severe
MR (adulthood)
 A triplet or repeat
mutation on the X
chromosome
interferes with the
production of FMR-1
protein which is
essential for normal
brain functioning
 Most people have 29
repeats at this end of
their X chromosome
but people with FX
have over 700 repeats
 Males: Intellectual
Disability, large ears,
long face, soft skin,
large testicles, flat
feet, double-jointed
fingers. They may
also have: social
anxiety, poor-eye
contact, tactile
defensiveness,
ritualistic forms of
greeting
 Females: milder
presentation of the
characteristics

29. Causes of Mental Retardation
Chromosomal Disorder Cause Characteristics
• William Syndrome
 Results in learning
problems, attention
deficit disorder,
anxiety, phobias but
they have outgoing
personality
 Occurs equally in both
male and female and
in every culture
 WS is caused by the
deletion of a portion of
chromosome 7
 The deleted area
includes more than 25
genes so amount of
genetic material
deleted may vary
 Deletion of
chromosomes are due
to random events that
occur in eggs or
sperm from their
parents
 Elfin or dwarf-like
features (e.g. small
eye openings, broad
forehead, short nose
with a broad tip, full
cheeks, wide mouth
with full lips, and
dental problems)
 They lack reserve
toward strangers
 Weak in visual-spatial
skills
 Often hyperactive

31. Causes of Mental Retardation
Chromosomal Disorder Cause Characteristics
• Prader-Willi
syndrome
 Syndrome disorder
 Associated with mild
retardation and
learning disability
 PWS is caused by the
deletion of a portion of
chromosome 15
 May also occur if the
person has a copy of
chromosome 15 from
the maternal side
instead of each of the
parent
 Infants: floppy-
muscles, feeding
difficulties, delayed
development
 Childhood: insatiable
appetite that may
result to chronic
overeating
(hyperphagia) or
obesity
 Beh. Problems are
common: impulsitivity,
aggressiveness, OCD
and tantrums

32. Causes of Mental Retardation
Chromosomal Disorder Cause Characteristics
 Translocation, or
mutation that
inactivates that
paternal chromosome
15
 Physical features:
narrow forehead,
almond-shaped eyes,
triangular mouth,
short stature, small
hands and feet. Some
may have unusually
fair skin and light
colored hair
 Male and female
affected may have
underdeveloped
genitals. Most are
also infertile

34. Causes of Mental Retardation
Chromosomal Disorder Cause Characteristics
• Phenylketonuria
(PKU)
 Inborn errors of
metabolism
 Genetically inherited
 A child is born without
an important enzyme
to break down an
amino acid called
Phenylalanine (Phe)
found in dairy and
protein rich foods
 PKU is inherited if
both the mother and
the father is a carrier
of the defective gene
 Because of the failure
to breakdown the
Phe, this causes brain
damage, that results
in aggressiveness,
hyperactivity, and
severe mental
retardation
 Symptoms may
include: beh. And
social problems,
seizures or jerking
movements,
hyperactivity, skin
rashes, microcephaly,
musty odor in the
child’s breath, skin or
urine due to too much
Phe.
 They have fair skin
and blue eyes

36. CRANIAL Malformation
• Occurs in developmental disorders of
brain formation
– Anencephaly the major portions of the
brain are absent. This is a major neural
tube defect, that is, it occurs in the brain
or in the spinal cord.
– Microcephaly the skull is small and
conical, the spine is curved and typically
leads to stooped portion and severe
mental retardation

37. CRANIAL Malformation
– Hydrocephaly blockage of
cerebrospinal fluid in the cranial cavity
causes an enlarged head and undue
pressure on the brain.

38. ANENCEPHALY

39. MICROCEPHALY

40. HYDROCEPHALY

41. Mental Retardation may also occur due to
environmental influences such as:
– Maternal Malnutrition
– Irradiation during pregnancy
– Juvenile diabetes mellitus
– Fetal alcohol syndrome or FAS
FAS is one of the leading causes of MR. This is
due to the mother’s excessive alcohol use
during pregnancy

42. Fetal Alcohol Effect or FAE happens due to
the mother’s prenatal alcohol exposure. FAE is
a condition associated with hyperactivity and
learning problems. It is characterized by
cognitive impairment, sleep disturbances, motor
dysfunctions, hyperirritability, aggression and
conduct problems. FAS’ incidence is higher
than DS and cerebral palsy

43. FAS/FAE

44. Causes of Mental Retardation
B. Perinatal (during birth) mental retardation
may occur by:
- Intrauterine Disorders such as
maternal anemia, premature delivery, abnormal
presentation, umbilical cord accidents and
multiple gestations in the case of twins, triplets,
quadruplets and other types of multiple births.
Birth trauma may result from anoxia or cutting
off of oxygen supply to the brain.

45. Causes of Mental Retardation
B. Perinatal (during birth) mental
retardation may occur by:
-Neonatal Disorders such as
intracranial hemorrhage, neonatal seizures,
respiratory disorders, meningitis,
encephalitis, head trauma at birth.

46. Causes of Mental Retardation
C. Postnatal and Environmental (after birth)
mental retardation may occur due to:
- head injuries cerebral concussion,
contusion or laceration
- infections encephalitis, meningitis,
malaria, German measles, rubella;
- demyelinating disorders post
infectious disorders, post immunization
disorders

47. Causes of Mental Retardation
C. Postnatal and Environmental (after birth)
mental retardation may occur due to:
- Degenerative disorders Rett
syndrome, Huntington disease, Parkinson’s
disease;
- Seizure disorders – epilepsy, toxic-
metabolic disorders such as Reye’s syndrome,
lead or mercury poisoning
- Malnutrition – especially lack of
proteins and calories;

48. Causes of Mental Retardation
C. Postnatal and Environmental (after
birth) mental retardation may occur due to:
-Environmental deprivation such as
psychosocial disadvantage, child abuse and
neglect, chronic social/sensory deprivation

49. Though accidents,
particularly vehicular
accidents, are the leading
causes of childhood head
injuries, the shaken baby
syndrome, which is a type of
child abuse when a crying
infant is violently shaken by
a frustrated caregiver, can
result to head injury. This
often results in internal
bleeding and brain damage,
or in some cases, even
death.

50. Cultural-familial retardation refers to the
existence of lowered intelligence of unknown
origin associated with a history of mental
retardation in one or more family members.

51. Diseases of the mother during pregnancy may
also result in retardation. Infections caused by
sexually transmitted diseases such as syphilis,
gonorrhea, AIDS, toxoplasmosis (blood
poisoning) and rubella can have negative
effects on the developing fetus. Maternal
rubella is most likely to cause retardation,
blindness, or deafness when the disease
occurs during the first trimester of pregnancy.