Lecture 6 - Atypical Neurodevelopment

Question 1

What is the genetic component of ASD?

Answer 1

• If your sibling has ASD, you have a 5% chance of also having ASD
• If a monozygotic twin has ASD, there is a 60% chance that the other twin will have ASD

Question 2

How many case of ASD are explained by a single genetic mutation?

Answer 2

About 5%

Question 3

What chromosome have they found strong evidence for?

Answer 3

Chromosome 7 and 17

Question 4

What chromosomes have they found weaker evidence for?

Answer 4

Chromosomes 2, 5, 11, 15, 16 and X

Question 5

What are some genes on chromosome 7 and 17 that could be responsible for it?

Answer 5

Chromosome 17 - Seratonin Transporter

Chromosome 7 - Transcription Factor EN2

Question 6

What is the gene on chromosome 11?

Answer 6

Neurxin 11 (cell to cell communication)

Question 7

What do several other genes show association with?

Answer 7

Glutamate Action

Question 8

Why doe ASD happen early to mid development?

Answer 8

As many genes are being activated early to mid development

Question 9

What do females with ASD have compared to males?

Answer 9

Greater mutation load (have more signs of ASD)

Question 10

What are many of the mutations with ASD?

Answer 10

De novo mutations

Question 11

What are De Novo Mutations?

Answer 11

Not passed down from a family member, happened spontaneously in the embryo

Question 12

How many genes are there with De Novo mutations?

Answer 12

159 genes

Question 13

How many clusters do the De Novo mutations fall into?

Answer 13

4 clusters

Question 14

What are the 4 clusters of De Novo Mutations (functional families of genes)?

Answer 14

1. Chromatin/DNA modifications/regulation
2. Postsynaptic Density
3. Neuronal signalling/cytoskeleton
4. Activity of Ion channel s

Question 15

What is an example of an environmental factor that caused ASD?

Answer 15

Thalomide - babies were born with birth defects and cognitive defects such as ASD

Question 16

What is the ASD Neurological phenotype?

Answer 16

Impaired face recognition
- Increased risk of prosopagnosia
- Difficulties recognizing emotions from faces
- Abnormal amygdala activation when viewing faces

Question 17

What other neurological reduction do ASD individuals have?

Answer 17

Reduced mirror neuron system
(If they see someone else riding a bike, they perceive it as they are riding a bike)

Question 18

What do we see prenatally with ASD?

Answer 18

A slight undergrowth

Question 19

What do we see around 4 - 16 months with ASD?

Answer 19

A rapid or large overgrowth (predicts the severity of the ASD)

Question 20

What age does a slow down in brain growth rate occur?

Answer 20

1 - 5 years

Question 21

What happens during adolescence with ASD?

Answer 21

Their brain is no different compared to a normal healthy brain of an average individual

Question 22

What do all ASD children have?

Answer 22

A high density of local connections in their temporal lobe

Question 23

What do high severity ASD children show?

Answer 23

Having low density local connections in the frontal lobe

Question 24

What do ASD children with high brain hyperconnectivity have?

Answer 24

Increased social deficits

Question 25

What do ASD children show regarding neural fluctuations

Answer 25

High neural fluctuations

Question 26

What neurotransmitter do ASD individuals exhibit low levels of?

Answer 26

Oxytocin

Question 27

What is Oxytocin?

Answer 27

Social Bonding and Love Neurotransmitter

Question 28

What happened to oxytocin in ASD patients

Answer 28

It was a mutated form

Question 29

What has studies with oxytocin administration shown?

Answer 29

Improvements in social domain, emotion recognition, eye contact, socialization, repetitive behaviours and communication - however not viable as a single treatment

Question 30

How often does Williams syndrome occur in people?

Answer 30

1 in 7500 people

Question 31

What do people with Williams Syndrome have?

Answer 31

A low IQ (intellectual disability)

Question 32

What are people will Williams syndrome good at?

Answer 32

Amazing language abilities - extremely talkative and good voice intonation

Question 33

What are typical behaviours of a Williuams syndrome individual?

Answer 33

Poor drawing and spatial skills (contrast)

Good Musical Abiltiies

Empathetic, social

Very good face recognition (contrast)

Preoccupied with a Single Activity

Question 34

What are Diagnostic Indicators of Williams Syndrome?

Answer 34

1.) Elfin Features

2.) Severe impairment in spatial cognition

3.) Cardiac Problems

4.) Emotional Immaturity

Question 35

What type of disorder is William’s Syndrome?

Answer 35

A genetic disorder

Question 36

What did they find on Chromosome 7?

Answer 36

A deletion that involved 25 genes

Question 37

What did one of those genes contain?

Answer 37

Elastin - gives elasticity to organs and tissues

Question 38

What does the loss of Elastin show for Williams Syndromes people?

Answer 38

Big Elephant Features and the cardiac problems

Question 39

How many Williams Syndrome people have that deletion on chromosome 7 (lack elastin gene)

Answer 39

95%

Question 40

What is a good diagnostic test for Williams Syndrome?

Answer 40

A blood test for elastin

Question 41

What are the Anatomical deficits on a Williams Syndrome patient?

Answer 41

Smaller occipital and parietal lobes
(explain the lack of spatial abilities)

Question 42

What Anatomical Parts are normal?

Answer 42

Frontal Lobe and Temporal Lobe

(good language abilities)

Question 43

What Anatomical changes do Williams Syndrome patients see?

Answer 43

Changes in the Limbic System
(Why they experience intense emotions)