Neurodevelopmental disorders

Question 1

Neurodevelopmental disorder definition

Answer 1

any condition that is associated with atypical brain development
“Disorders that are of a genetic or multifactorial origin that result in one or more specific cognitive deficits. These deficits are present early in life and extend into adult life without showing relapse or remission.”

Question 2

Diagnosis

- 3 steps

Answer 2

1 = referral, usually from a GP or health visitor (young children)
2 = formal assessment (NHS), usually diagnosis is made by a clinical psychologist or clinical geneticist. (This may be a multi-disciplinary diagnostic assessment --> based on DSM-5/ ICD10 criteria)
3 = post-diagnostic support eg. in school support such as speech and language therapy/ classroom assistance (getting post-diagnostic support in  place can be difficult)

Question 3

Disorders with an established genetic basis?

Answer 3

Down’s syndrome

Sotos

Question 4

Down’s syndrome
cause?
features?

Answer 4

caused by: presence of all or part of a 3rd copy of chromosome 21 (47 instead of 46)
- most common chromosome abnormality in humans
- physical growth delays, a particular set of facial characteristics and intellectual disability
- tend to develop learning skills throughout childhood but then this rate of learning slows down.
After the age of 12 children can find it quite challenging to learn new things

Question 5

Sotos syndrome
cause?
features?

Answer 5

caused by mutations in the NSD1 gene

• physical overgrowth during the first years of life
• children with sotos are often taller, heavier and have larger heads than their peers
• often have intellectual disabilities
• quite specific cognitive profile (good visuospatial reasoning, better verbal reasoning compared to non-verbal, poor quantitative reasoning)

Question 6

Disorder with a less clear genetic basis

Answer 6

autism spectrum disorder

Question 7

Autism spectrum disorder
cause?
Denovo mutation?

Answer 7

• complex genetic basis
• 1000s of genes implicated
• unclear whether ASD is explained more by rare mutations or by rare combinations of common genetic variants
• currently no genetic test, diagnosis is made on the basis of behaviour
• certainly is a heritable component for some individuals

(for some it may be a Denovo mutation = present for the first time in one family member due to a mutation)

Question 8

Development of neurodevelopmental disorders

Answer 8

• each individual changes and develops over time
• complex interaction of genes and environment:
• in utero (eg. maternal diet, infection, stress)
• early years can be a critical period

Question 9

Neurodiversity

Answer 9

an approach to learning and disability that suggests that diverse neurological conditions appear as a result of normal variations in the human genome

• neurological differences should be recognised and respected as a social category
• neurotypical = individual not affected by a neurodevelopmental disorder. standard cognition
• non - neurotypical = those affected by a developmental disorder eg. ASD

Stigma around neurodev disorders but it was found autistic individuals used identity first language eg. autistic adult, rather than adult with autism
= not ashamed of identity

Question 10

Methodology for studying neurodevelopmental disorders

Answer 10

population based prevalence studies
behavioural observation
parent/teacher questionnaire
behavioural experiments eg. eye tracking, standardised cognitive experiments (usually for infants)
cog neuro experiments eg. FMRI, EEG = looking for brain differences
semi-structured interviews