Genetics - Williams Syndrome

Question 1

Definition

Answer 1

Deletion of genetic material on one copy of chromosome 7 = person only having a single copy of the genes on this deleted region (on the other chromosome 7).
- It usually the result of a random deletion around conception, rather than being inherited from an affected parent.

Question 2

Signs and symptoms

Answer 2

• Broad forehead
• Starburst eyes (a star-like pattern on the iris)
• Flattened nasal bridge
• Long philtrum
• Wide mouth with widely spaced teeth
• Small chin
• Very sociable trusting personality
• Mild learning disability

Question 3

Key features of William syndrome

Answer 3

• Very sociable personality,
• Starburst eyes
• Wide mouth with a big smile.
  It is worth remembering the association with supravalvular aortic stenosis and hypercalcaemia, as these are unique features that are easy to test in exams.

Question 4

Associated conditions

Answer 4

• Supravalvular aortic stenosis (narrowing just above the aortic valve)
• Attention-deficit hyperactivity disorder
• Hypertension
• Hypercalcaemia

Question 5

Treatment

Answer 5

No cure
MDT approach to managing individual problem + supporting the patient and family:
- Echocardiograms and blood pressure monitoring are important to assess for aortic stenosis and hypertension.
- A low calcium diet may be required to control hypercalcaemia, and they should avoid calcium and vitamin D supplements.