Rett syndrome

Question 1

Do girls get rett syndrome from their mother or father?

Answer 1

father

Question 2

MeCP2 (gene) controls gene expressions through ____ silencing. What role does it have in CNS
Hint: transcriptional or translational

Answer 2

Transcriptional
Role: represses transcription from already methylated gene promotors. Involved in development and maturation of neurons and synapses

Question 3

MeCP2 (protein) is a DNA binding protein with a ____binding domain

Answer 3

Methyl-binding domain

Question 4

MeCP2 (reduces/increases) mRNA produced for other genes and keep genes inaccesible by keeping ____ condensed

Answer 4

reduces mRNA

Chromatin

Question 5

MeCP2 regulates ____ synapses and mutations to MeCP2 result in ___ dendrites and ___ neurons

Answer 5

Excitatory

Simplified dendrites and smaller neurons

Question 6

BDNF is dysregulated in RETT as MeCP2 binds to the promotor region of BDNF, what is the role of BDNF

Answer 6

Supports neuronal formation/survival. dendritic branching, plasticity, LTM, muscle repair/regeneration.

Question 7

List 5 Physical phenotypes

Answer 7

1. Stereotypic hand movements
2. psychomotor regression
3. Gait difficulties
4. Growth failure esp. head/brain
5. Teeth grinding

Question 8

How do people with Rett syndrome behave socially?

Answer 8

Socially withdrawn

Question 9

List 1 cognitive phenotype

Answer 9

Intellectual disability

Question 10

List 4 medical conditions associated with Rett syndrome

Answer 10

1. cardiorespiratory failure
2. Seizures/epilepsy (60-80%)
3. sleep difficulties
4. gastrointestinal issues
5. osteopenia (reduced bone density)
6. scoliosis (8% in toddlers, 80% at 16 years)

Question 11

Timeline: list the 5 stages including ages

Answer 11

1. normal development 6-18months
2. arrest of development 6months to 2.5yrs
3. rapid regression 1-4 years
4. stabilisation 3-10 years
5. late stage deterioration 10+ years

Question 12

In which stage do autistic traits and hand stereotypies appear?

Answer 12

3. rapid regression stage (1-4 years)

Question 13

In what stages does anxiety most often appear?

Answer 13

4. stabilisation (3-10years)

Question 14

Prevalence

Answer 14

1:10,000 females

Question 15

Name the 6 variations of Rett syndrome due to X inactivations

Answer 15

1. preserved speech
2. delayed onset
3. congenital onset
4. early seizure onset
5. mild learning disabilities
6. normal carriers

Question 16

How is the substantia nigra affected

Answer 16

depigmentation in cells of substantia nigra, loss of mecp2 in neurons that release dopamine leads to motor deficits.

Question 17

Brains, neurons and dendritic fields are ____ in rett than in fragile x

Answer 17

smaller

Question 18

increased pruning (less connectivity and fewer neurons) is associated with which syndrome: rett or fragile x

Answer 18

rett

Question 19

Fragile x mostly makes synapses more active, what is the effect in rett syndrome?

Answer 19

Some areas more active e.g. brain stem whereas other areas less active e.g. sensory areas

Question 20

Grey matter in PFC, parietal, temporal and occitipatal regions are:

Answer 20

PFC: decreased
Parietal: decreased
Temporal: decreased
Occiptial: preserved