Autism

Question 1

Early diagnostic criteria of autism (1980)

Answer 1

1. Onset before 30 months of age.
2. Impaired social development – lack of social responsiveness.
3. Bizarre responses to environmental stimuli, resistance to change.
4. Delayed and deviant language development if speech present.

Question 2

Triad of impairments diagnosis (1992)

Answer 2

1. Reciprocal social interaction skills.
2. Repetitive stereotyped behaviours, inflexibility.
3. Communication, non-verbal skills, imagination.

Question 3

Current conceptualisation of autism

Answer 3

Now seen as a diad of symptoms – an overlap of communication problems with repetitive and repetitive stereotyped behaviours and interests, and sensory sensitivities.

• language delay no longer a criterion.

Question 4

Prevalence of autism - prevalence peaks.

Answer 4

• 1980: 4 per 10,000
• 1992: 5 per 10,000
• 2013: >100 per 10,000

The prevalence in adolescence (in the UK) is said to be about 2.5%. there is a peak in prevalence in adolescence.

Peak in adolescence is around 12 to 19 years of age.

Question 5

what are the three classes of genetic risk for autism identified:

Answer 5

1. Gene mutation – identified by exome sequencing and DDD
2. Copy number variants
3. Polygenic risk.

Question 6

Phenotypic spectrum fo ASD

Answer 6

Sex – ASD was assumed to be much more prevalent in men but relates to this concept of masking.

Social behaviour – is influenced both by polygenic risk for ASD and de novo LoF.

Motor skills – only influenced by de novo variants.

Question 7

Developmental and functional changes in neurobiology of autism: (ONE STUDY SUGGESTED – Satterston et al., 2020)

Answer 7

Rare coding variants could be parsed into two broad groups:
- ASD predominant
- ASD and neurodevelopmental delay

• Prenatal gene expression regulatory (GER) anomalies lead to ASD and neurodevelopmental delay (DD/ID)
• Postnatal neuronal communication (NC) genes lead to ASD predominant phenotypes.

Question 8

ASD: Fu et al., 2022 – suggested

Answer 8

some rare variants are strongly associated with ASD, but not neurodevelopmental delay (intellectual disability).