L2 Genetic Conditions

Question 1

What is Fragile X syndrome?

Answer 1

A cause of neurodevelopmental differences
Caused by a single gene abnormality
Can be studied from early childhood
1/4000 males
1/5000 females
Distinctive physical, intellectual, behavioural and emotional features

Question 2

What is the physical profile of FXS?

Answer 2

May or may not be present
More common in males
Broad forehead
Large ears
Arches palate
Enlarged testicles
Flat feet

Question 3

What is the behavioural profile of FSX?

Answer 3

Social avoidance
Distractibility
Irritability
High activity level
Repetitive motor behaviours
Language problems
Strengths - imitation, visual learning, sensitive, humour

Question 4

What causes FXS?

Answer 4

FXS is caused by a narrowing end of the X chromosomes
FMR1 gene located at fragile site (CGG)
If this repeats too many times, genes become faulty

Question 5

What are the sex differences of FXS?

Answer 5

All men who have full mutation will have FXS
Women with full mutation will be carriers - half the cells with faulty genes will be switched on

Question 5

What is the inheritance of FXS?

Answer 5

Passed on by mother carriers
Daughters may be carriers with some symptoms
Sons may have full FXS

Question 6

What is Down Syndrome?

Answer 6

Extra copy of chromosome 21
1/1000

Question 7

What is the physical profile of DS?

Answer 7

Round flat face
Small chin
Protruding tongue
Short neck
Broad
Short arms and legs
Gastroesophageal reflux
Sleep apnoea
Thyroid dysfunctions
58 years (life expectancy)

Question 8

What is the behavioural profile of DS?

Answer 8

DS have lower aggression, antisocial behaviour, property destruction, attention seeking
They are predisposed to depression

Question 9

What is the neurological profile of DS?

Answer 9

Reduced size of brainstem and cerebellum
Reduction in cortical granular neurons
Smaller hippocampal volumes
Increase in Alzheimer like plaques

Question 10

What are the key features of FXS and DS?

Answer 10

Intellectual disability is implicated in FXS and DS
Similar IQ levels and mental age
Differences in behaviour and psychopathologies

Question 11

What is receptive language?

Answer 11

Comprehension of language, listening and understanding messages
Tested using BPVS - match the picture to the word

Question 12

What is expressive language?

Answer 12

Ability to produce language, verbal and written
Tested using WAIS - generate a definition of a word

Question 13

What is a Test for Auditory Comprehension of Language (TACL)?

Answer 13

Hear a word and chose the matching photo
FXS performed better

Question 14

What did Munir 2000 find about their attentional profiles?

Answer 14

Compared boys with FXS boys with DS
Presented with objects and had to find black eggs
Not conclusive but FXS have a stronger language strength
Important to remember that it is measured against those of the same mental age not actual age

Question 15

What is cognitive inhibition?

Answer 15

Preventing a certain behaviour
Munir compared boys with FXS to boys with DS
Say aloud the numbers and then swap so when they see a one they say two

Question 16

What did Wilding find about executive function?

Answer 16

Types of errors differed between groups
FXS and DS pattern similar but FXS more impaired
Difficulties in inhibiting previously successful response

Question 17

What are the key cognitive features of FXS?

Answer 17

Difficulties attending processing of complex sequential information
Tangential and preservative language

Question 18

What are the key cognitive features of DS?

Answer 18

Impaired processing of verbal language information
Increased risk of early onset Alzheimer’s disease

Question 19

How are genes, brain and cognitive linked in FXS and DS?

Answer 19

Mixed evidence linking genes and cognitive in FXS
No clear link between FMRP and general measures of performance but some evidence to suggest FMRP relates to frontal lobe
In DS many genes are affected so easier to investigate links between brain and cognition