Developmental defects of head and neck

Question 1

What causes first arch syndrome?

Answer 1

Failure of neural crest cells to migrate into 1st pharyngeal arch

Question 2

Which structures of the head and neck have developmental defects in first arch syndrome?

Answer 2

Eyes

Ears

Palate

Mandible

Question 3

What is an example of a first arch syndrome?

Answer 3

Treacher-Collins syndrome

Question 4

What causes Treacher-Collins syndrome?

Answer 4

Genetic defect
dysfunctional protein
negative effect on neural crest cell migration

Question 5

What is the inheritance pattern of Treacher-Collins syndrome?

Answer 5

Autosomal dominant

Question 6

What causes diGeorge syndrome?

Answer 6

Deletion on chromosome 22

Question 7

Which structures in the head and neck have developmental defects in diGeorge syndrome?

Answer 7

Parathyroid glands

Thymus gland

Question 8

How are the parathyroid and thymus glands affected in diGeorge syndrome?

Answer 8

Absence of parathyroid glands

Congenital thymic aplasia

Question 9

How does diGeorge syndrome affect head and neck development?

Answer 9

Disruption of development of 3rd and 4th pharyngeal pouches

due to disruption of neural crest cells