Intellectual Disabilities

Question 1

Define intellectual disability

Answer 1

• Significant impairment in intellectual function
• Manifest UNDER 18 YEARS OF AGE
• Lasts longer than 6 months
• Restricts everyday activities

Question 2

Congenital vs acquired intellectual disability

Answer 2

• All occur during development (before 18 years)
• Congenital occurs as a result of changes that were there at birth (e.g. downs syndrome, fragile X)
• Acquired is from changes that occurred after birth (e.g. meningitis, TBI)

Question 3

List 5 common intellectual disabilities seen in adult Australians + outline features

Answer 3

1. Down’s sydrome (trisomy 21; intellectual impairment, characteristic facial features)
2. FASD (behavioural issues, cognitive dysfunction, memory and executive function issues)
3. Fragile X syndrome (autism features, behavioural problems)
4. Cerebral palsy (depends on area of cortex)
5. Tuberous sclerosis complex (diffuse benign tumours, cognitive/behavioural problems, heart/kidneylung/eye problems downstream of tumours themselves)

Question 4

Common comorbidities/problems in people with intellectual disabilities

Answer 4

• Communication/daily living limitations
• Psychiatric comorbidities (e.g. depression/anxiety)
• Physical health issues (obesity/metabolic syndrome in prader willi/down syndrome)
• Sensory issues (such as hearing/vision loss)
• Social/economic limitations

Question 5

?Intellectual Disability Hx

Answer 5

• Antenatal (abnormal scans, maternal exposure/infection)
• FHX (other members with IDs?)
• Trauma history (falls? car accidents?)
• Infection (meningitis? encephalitis?)
• Developmental delay?

Question 6

Stats regarding reduced QOL of people with intellectual disability

Answer 6

• Reduced life expectancy (~26yrs)
• Double rate of ED presentations
• Many live in/near poverty (~45%)
• 90% of women have been sexually abused
• 50% have mental health diagnosis

Question 7

Investigations for suspected intellectual disability diagnosis

Answer 7

• Genetic microarray testing
• DNA studies for fragile X syndrome
• Urinary organic acids

Question 8

Genetic aetiology of tuberous sclerosis complex and intellectual disability

Answer 8

• TSC1 (hamartin) or TSC2 (tuberin) synthesis impaired by mutation in corresponding gene
• No inhibition of mTOR pathway, leading to increased cell growth
• Leads to diffuse, benign cell growth
• When they affect the brain, these can lead to intellectual disability and seizures/cognitive disabilities