CD: WS and RS Flashcards
What is Williams syndrome?
Genetic condition present at birth causing developmental disorder affecting many parts of the body
What is Williams syndrome characterised by? (4)
- Cardiovascular disease
- Developmental delays
- Distinctive fail features
- Mild-moderate intellectual disability
What is the prevalence of Williams syndrome?
1/7,500 - 1/10,000
Equal across males and females, and cultures
Summarise the aetiology of Williams syndrome (4)
- Spontaneous deletion of 26 to 28 genes on chromosome 7 in either the egg or sperm
- Deletion is present at time of conception
- Extent of deletion varies between individuals
- Some cases are inherited
What causes the features of Williams syndrome? (2)
- Elastin gene deletion accounts for many of the physical features
- Symptoms will depend on genes deleted eg. missing ELN -> cardiac problems
Describe the inheritance pattern of Williams syndrome (3)
- Autosomal dominant pattern
- One copy of the altered chromsome 7 in each cell is sufficient to cause the disorder
- 50% chance of passing to offspring
What are the distinctive facial features of Williams syndrome? (6)
- Broad forehead
- Short nose with broad top
- Full cheeks
- Wide mouth with full lips
- Older children and adults: longer face and gaunt
- Dental problems
Describe the communication skills of someone with Williams syndrome (3)
- High level of sociability
- Very good communication
- High level of expressive language
Summarise the impact of Williams syndrome (6)
- Characteristic phenotype
- Good communication skills
- Cardiovascular problems
- Delayed growth
- Anxious but friendly personalities
- Learning difficulties
What cardiovascular problems are common in Williams syndrome? (3)
- Supravalvular aortic stenosis (SVAS) - narrowing of the large blood vessels carrying blood away from the aorta
- Can lead to shortness of breath, chest pain and heart failure
- High blood pressure
When is Williams syndrome usually diagnosed?
Before age 4
How is Williams syndrome diagnosed? (3)
- Clinical features
- Blood test for high calcium levels
- Genetic testing eg. fluorescent in situ hybridisation (FISH) or deletion/duplication testing
What is the prognosis of Williams syndrome? (4)
- Some = normal life span
- Medical challenges may reduce lifespan
- 3/4 have some degree of intellectual
- Most will need full time care
How is Williams syndrome treated? (4)
- Diet low in vitamin D to reduce calcium levels
- Supportive care
- Surgery for heart problems
- Medication
What is medication used for?
- Help management of other symptoms eg. ADHD, anxiety
What is Rett syndrome?
- Rare neurodevelopmental disorder affecting development in girls almost exclusively
What is the course of Rett syndrome? (2)
- 6-18m period of typical development
2. Then develops severe problems with language and communication, learning, coordination and other brain functions
What is the prevalence of Rett syndrome?
1 in 9,000 - 10,000
Summarise the aetiology of Rett syndrome
- Most = sporadic mutations
- Mutations of MECP2 gene
- Partial gene deletions and mutations in other genes
- Some are X-linked dominant inherited
What is the function of MECP2 gene?
- Provides instructions for making MeCP2 protein that is critical for normal brain function
- Involved in maintaining connections (synapses) between neurons
What do mutations in the MECP2 gene cause? (2)
- Alter the protein or result in less protein being produced
- Disrupting neuron and other brain cell functions
Describe the inheritance of Rett syndrome (2)
- Few families have more than one affected members
2. X-linked dominant pattern of MECP2 gene
What is the prognosis for males with mutations in MECP2 gene? (2)
- Often die during infancy
2. Some develop symptoms similar to Rett syndrome but are often milder
Summarise the impact of Rett syndrome (7)
- ASD-like difficulties
- Cardiac problems
- May develop scoliosis
- Intellectual disability is usually severe
- Gait abnormalities
- Abnormal sleep patterns
- Regression of skills
What are the signs of slowed development/regression in Rett syndrome? (6)
- Loss of purposeful hand use
- Compulsive hand wringing and hand-washing behaviour
- Slowed head and brain growth
- Seizures
- Difficulty walking
- Intellectual disability
What are the 4 stages of Rett syndrome?
- Stagnation
- Regression
- Plateau (2-10 years)
- Deterioration in movement
What are gait abnormalities found in Rett syndrome?
- Toe walking
- Unsteady
- Wide based
- Stiff-legged walk
How is Rett syndrome diagnosed? (2)
- Observations of early development
2. Genetic testing for mutated gene
What is the prognosis of Rett syndrome?
- Rare = little info about long-term prognosis beyond 40 years
- Cardiac abnormalities may increase risk of sudden death
- Many survive well into adulthood
- Most are dependent on 24 hour care
How is Rett syndrome treated?
- Supportive care eg. SLT, OT, PT, dietitian
- Medication
- Regular evaluation eg. scoliosis, cardiac abnormalities
What is medication used for in Rett syndrome?
- Control seizures
- Breathing abnormalities
- Motor difficulties
