Mental retardation, now called intellectual disability, is characterized by impaired cognitive and adaptive functioning that is present in approximately 1% of the population. It is caused by genetic factors in about 5% of cases, prenatal issues in 30% of cases such as infections, and perinatal problems like prematurity in 10% of cases. The causes can be classified based on genetic testing and family history, prenatal or postnatal onset. Diagnosis involves assessing deficits in intellectual and adaptive functioning through cognitive tests and determining if onset was before age 18. Prevention strategies include public education, neonatal screening, and early intervention programs.

1. Mental Retardation

2. Contents
 Definition
 Prevalence
 Classification
 Causes
 Clinical Evaluation
 Diagnosis
 Prevention

3. Definition
Mental Retardation Intellectual disability (intellectual
developmental disorder) replaces the term mental retardation
(MR) as intention of decreasing stigmatization. Intellectual
disability (ID) is characterized by impaired cognitive and
adaptive/social functioning. Severity level is currently based
on adaptive functioning, indicating the degree of support
required.

4. The Classical definition comprises
3 components :
1- subaverage intellectual function .
2- that result from an injury , disease or
abnormality before the age of 18 years .
3- resulting in impaired ability to adapt to the
environment .

5. Prevalence
Mental retardation is present in about
1% of the population.

6. DSM-5 MR Classification
A single IQ score does not adequately capture this and is no longer used solely to
determine ID severity.is the condition of having an IQ measured as below 70 to 75 and
significant delays or lacks in at least two areas of adaptive skills.
IQ classification:
I.Q.(intelligence quotient) is 100; normal ranges from 90 to 110
1-Border line { IQ 70-80 }
2-mild MR { IQ 55-70 }
3-moderate MR{ IQ 40-55 }
4-sever MR { IQ 25-40 }
5-profound MR { IQ below 25 }

7. Etiology
 Unknown “ 30-40 % “
 Genetic “ 5% “
 Early embryonic ( prenatal ) “ 30% “
 Prematurity , IUGR (perinatal) “ 10 % “
 Acquired medical condition (trauma ,
infection ..) “ 5% “
 Environment “ 5-20% “

8. Causes of MR
Cause Examples
Genetic  Down syndrome: (1/700 live births)
 Fragile X syndrome: Involves mutation of X
chromosome, second most common cause
of intellectual disability, males > females
 Others: Phenylketonuria, familial mental
retardation, Prader–Willi syndrome, Williams
syndrome, Angelman syndrome, tuberous
sclerosis
Prenatal Infection and toxins (TORCH):
 Toxoplasmosis
 Other (syphilis, AIDS, alcohol/illicit drugs)
 Rubella (German measles)
 Cytomegalovirus (CMV)
 Herpes simplex
perinatal  Anoxia, prematurity, birth trauma, meningitis,
hyperbilirubinemia
Postnatal  Hypothyroidism, malnutrition, toxin exposure,
trauma

9. Fragile X syndrome (FXS)
• Large ears , Large testes (testicular
volume>30 ml in adults) , Plantar
crease , Hyperextensible joints , Broad
forehead, Increased hand width,
Increased hand length , Elongated face,
Mitral valve prolapse , Hypotonia ,
Hernia….

10. Clinical Evaluation
 Complete History :
 Examination :

11. History
»complete and detailed history«
complete systemic review
surgical history : trauma , accidents
medical illnesses : hospitalization , general heath
pregnancy history : maternal age , parity , infections..
birth : type , wt . GA ,complications , apgar score
Postnatal : incubator , ventilator , disease ..

12. History (cont.)
drugs: mother and child
developmental Hx : mile stones , loss it , speech
educational Hx : schooling , IQ tests
behavioral Hx : skills , attention , activity
family Hx : consanguinity , inherited ds ..
social Hx :

13. Examination
»complete and detailed examination«
• Growth parameters :
• Dysmorphic features :
• CNS examination :
• Other system and skin exam :
• IQ tests :
• Developmental testing :

14. Diagnosis
• Deficits in intellectual functioning, such
as reasoning, problem solving, planning,
abstract thinking, judgment, and learning.
• Deficits in adaptive functioning, such as
communication, social participation, and
independent living.

15. Prevention of MR
 Primary prevention:
Public education about need for prenatal care, dangerous of
pregnant women drinking alcohol………
 Secondary prevention:
 Treatment, as in special diet for PKU children
 Hypothyroidism: neonatal screening is relatively easy to make and the
treatment which is pure replacement therapy by the administration of oral
thyroxine, is both inexpensive and completely effective
 Tertiary prevention
School and community based educational, vocational and
skills training programs

16. THANK YOU
And finally
Hesham Shaban Elbaz Hend Gamal Mokhtar
Mohamed Mostafa Mohamed Naira Salah Gamal
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