Williams Syndrome
Developmental disorder characterised by:
- Intellectual disability
Usually visual-spatial. - Distinctive facies
- Cardiovascular abnormalities
Including:- Supravalvular aortic stenosis
- Abnormalities of coronary artery implantation
- Supravalvular aortic stenosis
Epidemiology and Risk Factors
Prevalence of 1:~7,500.
Pathophysiology
Genetic condition that is:
- Classified as autosomal dominant
- Involves deletion of 26-28 genes on chromosome 7
- The ELN gene encodes tropoelastin, which is involved in vascular wall development
Clinical Manifestations
Key characteristics:
- Distinctive facies
- Broad forehead
- Epicanthal folds
- Short nose
- Long philtrum
- Wide mouth
- Thick vermillion
- Mandibular hypoplasia
- Developmental delay
- Hypotonia
- Hypercalcaemia
Develops in infancy and resolves by ~4; unclear cause. - Cardiac disease
- Present in 80%
40% will require procedural intervention. - Includes
- Supravalvular AS
Non-compliant aorta narrows at the sinotubular junction, and ↑ AV leaflet degeneration. Severity usually remains stable in most patients. - Pulmonary artery stenosis
Often occurs with SVAS.
- Supravalvular AS
- Present in 80%
Diagnostic Approach and DDx
Investigations
Bedside:
- ECG:
- LVH
- Long QT
- TTE:
- Presence of AS
- Presence of PS
Imaging:
- Cardiac MRI
Management
Anaesthetic Considerations
- A
- Potentially difficult airway
Secondary to mandibular hypoplasia.
- Potentially difficult airway
- C
- Evaluate cardiac disease
- Supravalvular AS
- Coronary occlusion
- 5-lead ECG
- Defend coronary blood flow
- Minimise NPO time
- Maintain volume state
- Avoid fall in SVR/ in PVR
- Minimise NPO time
- Evaluate cardiac disease
- F
- Hypercalcaemia
Testing recommended every 2 years.
- Hypercalcaemia
Marginal and Ineffective Therapies
Complications
Include:
- Perioperative death
Likely due to myocardial ischaemia.
Prognosis
Key Studies
References
- Genetics Home Reference. Williams Syndrome. National Library of Medicine. 2019.
- Matisoff AJ, Olivieri L, Schwartz JM, Deutsch N. Risk assessment and anesthetic management of patients with Williams syndrome: a comprehensive review. Thomas M, ed. Paediatr Anaesth. 2015;25(12):1207-1215. doi:10.1111/pan.12775