Prader-Willi Syndrome

Question 1

What is the genetic cause of PWS?

Answer 1

Loss of paternally derived genetic information:

• Deletion
• mUPD
• Defect of IC

Question 2

Describe the physical phenotype of PWS.

Answer 2

• Short stature
• Small hands and feet
• Hypo-pigmentation
• Scoliosis
• Obesity

Question 3

Describe the behavioural phenotype of PWS.

Answer 3

Lying/stealing
repetitive behaviours
excessive eating and food seeking
temper tantrums
mood fluctuation/arguing
skin picking
Excessive Daytime Sleepiness

Question 4

What SIB is specific to PWS?

Which genetic cause is it more frequent in?

Answer 4

Skin picking (Arron et al., 2011)
Deletion (vs mUPD)

Question 5

What did Russell and Oliver (2003) find about eating in PWS?

Answer 5

Over-eating begins at 2 years when starvation mode beings, as babies with PWS do not suck/feed until 2 years.

Question 6

How much more do those with PWS eat compared to controls?

Answer 6

3x (Holland et al., 1995)

Question 7

Describe Hinton et al.’s (2005) study.

Answer 7

• Gave people with PWS a 1200 calorie breakfast.
• Half an hour later, they were hungry again
• Hunger brain regions activated in fMRI
• Suggests they are only briefly satiated

Question 8

What repetitive behaviours are apparent in PWS? Which did Moss et al. (2009) find to be significant?

Answer 8

Hoarding
Ordering
Preference for routine *significant*
Cleaning
Repetitive Questions *significant*

Question 9

What associations have been made between different aspects of the behavioural phenotype?

Answer 9

• Repetitive question and temper outbursts

Question 10

What are the strengths and weaknesses in the PWS cognitive phenotype?

Answer 10

Strengths: academic achievement, visual processing
Weaknesses: maths, auditory processing, short term memory

Question 11

What did Dykens (2002) find about PWS cognitive skills?

Answer 11

Higher jigsaw ability, possibly due to higher visual processing

Question 12

What is one deficit of executive functioning in PWS?

Answer 12

Task-switching (Woodcock et al., 2016)

Question 13

What did the Childhood Routines Inventory show about PWS?

Answer 13

• PWS scored higher in all areas

- Only significant in preference for routine and preferring things in a particular order

Question 14

What did longer RTs in attention switching paradigm positively correlate with?

Answer 14

repetitive questions and adherence to routines

Question 15

What usually follows a temper tantrum in PWS?

Answer 15

Sincere apologies: often can’t control emotions

Question 16

What did Tunnicliffe et al. (2013) find?

Answer 16

Switching behaviours related to temper outburst: see precursor behaviours in difficult switching task alone
- switched between both activities to show it was not activity but switching which was the issue

Question 17

What neural correlates are linked to compromised attention shift?

Answer 17

Fronto-parietal dysfunction

Question 18

What intervention helps with task-switiching?

Answer 18

Use object to represent/signal change

Question 19

What did Soni et al. (2008) find the mUPD subtype to be strongly associated with?

Answer 19

• Psychiatric illness
• 46/119 participants had history of psychiatric illness
• Deletion = depressive, mUPD = bipolar with psychotic