Learning Disability

Question 1

Outline the pathophysiology of Turners syndrome occur?

Answer 1

Inactivation of one of the X chromosomes in girls (all the genes unlike lyonisation)

Results in:
- Webbed neck
- Short stature
- Broad chest
- Gonadal dysfunction (amenorrhea and infertility) - ovarian failure pre-birth therefore puberty does not occur naturally
- Hypothyroidism
- Congenital cardiac abnormalities (1/3rd) - VSD or coarctation of the aorta
- Generally normal IQ - mean 90 - but may struggle with nonverbal communication, psychomotor and social skills

Only occurs in girls

Question 2

What gene is affected in Lesch-Nyhan syndrome?

Answer 2

HPRT1 - affects the production of hypoxanthine-guanine phosphoribosyltranferase (HGPRT)

This recycles purine bases hypoxanthine and guanine - as they build up they get converted to uric acid

It is X-linked recessive - virtually all cases are males

Without HGPRT dopaminergic pathways get affected particularly mesotelencephalic:
- substantia nigra to putamen –> dystonic motor ability
- Ventral Tegmentum to PFC and Nucleus Accumbens –> peculiar behaviour

Question 3

Outline some features of Lesch Nyhan syndrome?

Answer 3

Build up of uric acid:
- Hyperuricaemia
- Gouty tophi/arthritis
- Nephrolithiasis

IQ 60 - 70
Attentional difficulties - relatively preserved language and verbal ability

Self injurious behaviour - extinction at time of behaviour and restraints

Dystonia superimposed on hypotonia, usually cannot walk and wheelchair bound. May have choreoathetosis or corticospinal signs

Question 4

Loss or abnormality of psychological, physiological or anatomical structure or function is….

Answer 4

Impairment - refers to bodily structure and function

Question 5

Outline the genetics of Down’s syndrome?

Answer 5

Full trisomy 21 - not inherited - 95% of cases - nondisjunction 88% from Mum / 12% from Dad

Translocation - inherited - 2-3% of cases - balanced translocation

Mosaicism - not inherited - 2-3% of cases - occurs during fetal development at a random time point

Question 6

Classify intellectual disability according to IQs

Answer 6

Mild 50 - 70 (85%) - most lead normal lives

Moderate 35-49 (10%) - use simple language when talking, understand speech better, may be able to learn simple ADLs more complex requires support and supervision.

Severe 20 - 34 (3 - 4%) - may live independently with supervision

Profound < 20 (1 - 2%)

Question 7

Name some drugs known to cause dysphagia in LD

Answer 7

Clonazepam
Haloperidol
Metoclopramide
Phenothiazines

Question 8

Name some appropriate screening tools for dementia in LD?

Answer 8

DLD
DSDS - dementia scale for downs syndrome

Question 9

Name some risk factors for self-harm in those with LD?

Answer 9

Younger age
Lower developmental ability
Autistic symptoms
Sensory impairment

Question 10

What is the most common symptom of PTSD in those with learning diability?

Answer 10

Aggression
Disruptive/defiant behaviour

Others:
Self-harm
Agitation/jumpiness
Distractibility
Sleep problems
Depressed mood

Question 11

Is Schizophrenia reliably diagnosed in individuals with an IQ < 45

Answer 11

No psychosis NOS is used

Question 12

Are stimulant drugs as effective in individuals with LD?

Answer 12

May be less effective

Additionally could precipitate tics in those with tourette’s or ASD

Question 13

Are people with LD more or less likely to experience adjustment disorder?

Answer 13

Seems more likely - more sensitive to loss of loved ones / changing roles

Question 14

What is the co-morbid prevalence of the following conditions with LD?

Problem behaviour
Autism
Affective Disorder
Schizophrenia
OCD
ADHD
Personality Disorder
Psychotic Disorder
Anxiety Disorder

Answer 14

Problem behaviour - 22.5%
Autism - 7.5%
Affective Disorder - 6%
Schizophrenia - 3%
OCD - 0.7%
ADHD - 1.5%
Personality Disorder - 1%
Psychotic Disorder - 4%
Anxiety Disorder - 4%

Question 15

Name some signs of dyslexia?

Answer 15

• Confusing the order of letters in words
• Poor or inconsistent spelling
• Understand information when told verbally, but have difficulty with information that’s written down
• Put letters the wrong way round (such as writing ‘b’ instead of ‘d’)
• Pronouncing long words incorrectly and ‘jumbling’ up phrases (for example, saying ‘hecilopter’ instead of ‘helicopter’, or ‘beddy tear’ instead of ‘teddy bear’)
• Poor handwriting

Question 16

What factors may contribute to the development of learning disability?

Answer 16

Genetic factors
- i.e. Downs syndrome
- Deletions and duplications
- X-linked recessive and dominant conditions
- Mitochondrial and metabolic disorders
- Presumed polygenetic conditions like neural tube deficits

External prenatal factors
- Infections - rubella, CMV, syphillis, toxoplasmosis, HSV and HIV
- Toxins e.g. alcohol, drugs and opioids
- Maternal illness - diabetes, hypertension, hypothyroidism etc

Perinatal factors
- Premature infants and low birth weight
- Infections e.g. meningitis, encephalitis, neonatal septicaemia
- Birth asphyxia and intracranial haemorrhage
- Newborn complications - respiratory distress or hyperbilirubinaemia, hypoglycaemia

Postnatal factors:
- CNS infections, intracranial tumours
- Hypoxic brain injury
- Head injury
- Exposure to toxins
- Psychosocial environment

Question 17

What is social role valorisation?

Answer 17

SRV in LD is the idea of including and creating roles for people with LD in society would allow these individuals to be valued differently - expanded to include concepts of respect, opportunity, development of competence, individual living and individual choice

Question 18

Name a useful screening tool to assess for psychiatric symptoms in individuals with LD?

Answer 18

PAS - DD

Psychiatric assessment schedule for adults with developmental disability
- Available as a checklist for staff to decide who may need more detailed assessment and mini version without interview

Question 19

What specific LD syndrome’s occur with psychosis?

Answer 19

Usher’s syndrome - retinitis pigmentosa, congenital deafness, vestibulo-cochlear ataxia, LD in 23% and psychosis in 15%

Velo-cardio-facial syndrome

Prader Willi - association with psychosis

Question 20

Name some phenotypic features of downs syndrome?

Answer 20

• General hypotonia
• Oblique/upslanting palpébral fissures
• Small flattened skull
• High cheekbones
• Protruding tongue
• Short stature
• Overweight
• Wie nasal bridge
• Brushfield spots - grey or very light yellow spots on iris
• Epicanthic fold
• Low set ears
• SIngle plmar rease
• Syndactyly
• Short broad hands

Congenital features:
- VSD
- Mirtral valve disease
- Patent ductus arteriosus
- GI abnormalities
- Hirschsprung disease
- Umbilical and inguinal hernia

Question 21

What is the genetics of fragile X and name some features

Answer 21

Trinucleotide repeat (CGG) on X - on FMR1 gene Xq27.3
> 200 repeats considered pathological

More common in men > women
Elongated face, large ears, short stature, large testicles, hyper-extendible joints
Association with epilepsy and ASD (may behave similar too with shyness, poor eye contact, conversational rigidity)
Men affected have moderate/severe LD, women may only have mild LD (IQ tends to be dip pre-adolescent then stabilises with increases in adaptive functioning after this)

Accounts for 10-12% of LD in men
Men affected more than women

Question 22

How do Prader Willi and Angelman syndromes differ genetically and phenotypically?

Answer 22

PWS - 15q11 deletion - inherited from father:
- Hyperphagia
- Skin picking
- Obesity and striate
- Mild LD
- Small gonads, incomplete sexual development
- Hypotonia and delayed motor development
- Almond shpaed eyes, flat face, thin upper lip

Angelman syndrome:
- Happy disposition, paroxysmal laughter, hand flapping, clapping, ataxia T
- Severe/profound LD - with pronounced verbal delay
- Fair hair and blue eyes, microcephaly with a flat occiput (short and broad skull)
- Long face, prominent jaw and wide spaced teeth
- 90& have epilepsy

Question 23

The genetics of Williams syndrome is?

Answer 23

Deletion of 7q11

Features:
- Elfin like face
- Disinhibited socially and with strangers or anxious and fearful
- Advanced verbal skills but speech is superficial (cocktail party speech) (Verbal skills > visuospatial and motor) (typically mild - moderate LD)
- Supravalvular stenosis
- Sensitive hearing
- Hypercalcaemia
- Thyroid problems
- Renal problems

Question 24

How does Cri-du-chat present?

Answer 24

Results from deletion on 5p

Symptoms:
- Cat like cry
- Hypotonia
- Microcephaly
- Hypertelorism (increase in space between two body parts)
- Down turned mouth
- Severe to profound LD
- Epicanthal folds - parallel to nose
- Slanting palpebral fissures
- Miceognathia
- Hyperactive, stereotypes and self-injury
- Congenital heart disease and GI abnormalities

Question 25

Smith-Magnesis Syndrome presents with?

Answer 25

Pronounced self-injurious behaviour
Self-hugging
Hoarse voice
Mild/moderate LD (75%)
Sleep disturbance (decreased or absent REM)

Results from deletion (complete or partial of 17p11.2 (cognitive impairment correlates with the size of deletion)

Question 26

How does Edwards syndrome present?

Answer 26

Die soon after birth
Rocker bottom feet
Webbing of second and third toes
Severe LD

From Trisomy 18

Question 27

How does Patau syndrome present?

Answer 27

Severe intellectual disability
Babies often die soon after birth.
Most have congenital heart malformations, anophthalmia and a cleft palate.
Other common features include polydactyl, microcephaly, and overlapping of fingers over thumb

Question 28

How does tuberous sclerosis present as?

Answer 28

Hamartomatous tumours affecting various organs including brain, kidney and heart tissue
ADHD
ASD
Epilepsy is common
LD of all degrees
Depigmented skin patches (Ash Leaf Spots)
Fibromas of nails

Implicates to affect 16p and 9q - autosomal dominant
Type 1 and type. 2 exist

Question 29

How does Rubenstein Tabi present?

Answer 29

Short
Small heads
Friendly disposition
Moderate - severe LD
Propensity for self-stimulatory activities
Beaked nose
Short eye lashes
Broad thumbs and great toes
Thin upper lip

Question 30

Differentiate Aspergers from ASD?

Answer 30

No overt language delay or global cognitive impairment that can occur
Aspergers may have specifics difficulties non-verbal communication or executive functioning

Question 31

How does Rett syndrome present?

Answer 31

Almost exclusively females

Initial normal development (6 - 18 months) then regression:
- Loss of all acquired language skills
- Characteristic hand flapping movements
- Ataxia
- Psychomotor retardation
- Deceleration in head circumference resulting in micropcepahly
- Epilepsy and seizures with EEG abnormalities
- Breathing problems (hyperventilation, apnoea, and breath holding)
- Daytime somnolence

Often grow up to be wheelchair bound with no verbal ability
Xq28

Question 32

What is the incidence of Downs in women aged

a) < 25
b) 25 - 30
c) 30 - 35
d) 35 - 40
e) > 45

Answer 32

a) 0.5/1000
b) 0.7/1000
c) 5/1000
d) 25/1000
e) 36/1000

Question 33

What is a monosomy?

Answer 33

Only having one chromosome

Question 34

Name some features of foetal alcohol syndrome?

Answer 34

Microcephaly
Short palpebral fissures
Flat philtrum
Thin upper lip
Short stature
Small maxillae and mandibles
Mild - moderate LD
Irritability / inattention / memory problems

Question 35

Are people with Kleinfelters taller or smaller on average?

Answer 35

Smaller

Question 36

How is fragile X transmitted?

Answer 36

X-linked dominant

Females shower lower penetrance due to the protective effects of the second X chromosome

Question 37

How is Hunter’s syndrome inherited?

Answer 37

X - linked recessive - leads to an accumulation of Glycosaminoglycans

Question 38

Which LDs is epilepsy most common in?

Answer 38

Angelman syndrome, Rett Syndrome and Tuberous Sclerosis (90% for these conditions)

Down’s 5-10%
Fragile X 20-25%

Question 39

How is PKU transmitted?

Answer 39

Autosomal recessive

Question 40

Prescribing Lithium to those with LD what investigation should be done?

Answer 40

EEG - due to Lithiums ability to lower seizure threshold and the prevalence of epilepsy in those with LD