Downs Syndrome

Question 1

Genetics of Downs Syndrome

Answer 1

3rd chromosome 21 is present from the moment of conception. This is called a genetic trisomy. Result of a random mutation, rather than Down syndrome being inherited.

Question 2

Prevalence of Down syndrome against mother’s age

Answer 2

Age 30: less than 1 in 1000, age 35: 1 in 400, age 42: 1 in 60.

Question 3

3 types of Down syndrome

Answer 3

1. Standard Trisomy 21
2. Translocation (4%)
3. Mosaicism (2%)

Question 4

Standard Trisomy 21

Answer 4

Every cell has the 3rd chromosome 21

Question 5

Translocation

Answer 5

The extra 21st chromosome is attached to another chromosome

Question 6

Mosaicism

Answer 6

Only some of the cells have an extra 21st chromosome

Question 7

Is Downs syndrome inherited?

Answer 7

Most cases are not inherited (sporadic)

Downs Syndrome can be traced through families in less than 1% of people with the condition

It is very unusual for parents to have more than one child with Downs Syndrome

Question 8

Physical Phenotype of Downs syndrome

Answer 8

Phenotypic dysmorphic facial features found in 100% of affected individuals.

Identified by distinctive facial features and low muscle tone and loose joints

Question 9

Medical phenotype of Downs syndrome

Answer 9

• Sucking and feeding problems
• Congenital heart defects
• Hearing and vision deficits
• Respiratory problems

Question 10

Chapman and Hesketh (2000)

Answer 10

Verbal skills were strong with those with Downs (along with social functioning, self-help and daily living skills). Speech, language, verbal processing and motor functioning were weaknesses

Question 11

Lott and Dierssen (2010)

Answer 11

• Frontal lobe – Reduced volume and larger minicolumns with fewer cells
• Temporal lobe – Reduced volume, reduced number of cells, and altered microarchitecture of pyramid cells
• Basal ganglia – Normal
• Parietal lobe – Normal volume and altered microarchitecture of pyramid cells
• Hippocampal system – Altered microarchitecture of pyramid cells
• Basal prosencephalon – Early cholinergic degeneration
• Amygdala – Normal
• Cerebellum – Hypoplasia and reduced number of granule cells
• Brainstem – Altered serotoninergic, noradrenergic, and cholinergic systems

Question 12

Godfrey and Lee (2018)

Answer 12

Found impairments in Long Term Memory from school-age onwards. Deficits in both verbal and non-verbal working memory. Impairments got greater with age.

Impairments in verbal short term memory from school age and beyond. However, small effect size and mixed findings for non-verbal STM.

Impairments in verbal working memory from adolescence and beyond. Mixed findings for non verbal.

Question 13

Lanfranchi et al (2010)

Answer 13

Examined executive function s in Down syndrome.

Question 14

Miyake et al (2000)

Answer 14

Proposed that there are three main functions; Shifting, Inhibition, and Updating of working memory

Question 15

Loveall (2017)

Answer 15

Impairments in executive functions across the lifespan. There were also changes in functioning across the lifespan

Question 16

Martin et al (2009)

Answer 16

Pattern observed in Down Syndrome
* Phonological errors in speech production
* Poor speech intelligibility
* Receptive vocabulary/ comprehension unaffected
* Expressive vocabulary acquisition is delayed
* Syntax/ grammatical structure presents a particular challenge
* Some differences in pragmatics

Question 17

Cebula et al (2010)

Answer 17

Social cognition of those with Downs Syndrome
* Subtle differences in early attention e.g. slow to develop mutual gaze
* Fewer spontaneous gestures
* Difficulty in social referencing
* Difficulty in recognising emotions/ facial expressions of others

Question 18

Behaviour of those with Downs syndrome

Answer 18

They are perceived as cheerful, charming, affectionate and sociable. They show more positive facial expressions than TD people. Low risk of psychopathology compared to other ND people. They are prone to social distraction and have high rates of externalising behaviours.

Question 19

Dykens et al (2002)

Answer 19

Found evidence for behavioural difficulties and changes in behaviour across development

Question 20

Lifespan of Downs syndrome

Answer 20

In the 1940s, the average life expectancy for individuals with DS was 12 years

With medical breakthroughs and improvements in services, individuals with DS now enjoy life expectancies into their 60s

Question 21

Premature aging

Answer 21

At 35, many Downs syndrome people develop neuropathic changes similar to Alzheimers. There may be memory loss and changes to personality and behaviour.

Question 22

Down syndrome and dementia

Answer 22

Around 30% of people with DS are affected by dementia

Question 23

Interventions for Downs syndrome

Answer 23

• Physical features- Physical therapy
• Language- Speech and language therapy
• Behaviour- Emotional and behavioural therapies
• Ageing- Drug treatments and support services for ageing / dementia
• Early intervention
• Support for the family

Question 24

Neil and Jones (2018)

Answer 24

Conducted a systematic review of communication interventions for individuals with Downs Syndrome
* They concluded that favourable effects come from behaviour analytic approaches
* Important features are intensity of interventions e.g. frequency of sessions and opportunities to practice

Question 25

Hardee and Fetters (2017)

Answer 25

Conducted a review of exercise interventions in those with Downs Syndrome
* They concluded that there are many positive outcomes e.g. for balance, endurance strength, but also daily life activities and wellbeing
* Interventions included cardio-vascular training, strength training, swimming, and even judo