Microdeletion syndromes

Question 1

List the 4 microdeletion syndromes

Answer 1

1. DiGeorge
2. Velocardiofacial syndrome
3. Cri-du-chat
4. Williams

Question 2

What causes cri-du-chat?

Answer 2

Microdeletion of short arm of chromosome 5

Question 3

What causes Williams syndrome?

Answer 3

Microdeletion of long arm on chromosome 7, which includes elastin gene

Question 4

What are the 22q11 deletion syndromes?

Answer 4

DiGeorge

Velocardiofacial syndrome

Question 5

46 X,Y/X,X -5p

Answer 5

Cri-du-chat

Question 6

Hypercalcemia + well-developed verbal skills + cardiac defects + “elfin” facies + intellectual diasbility

Answer 6

Williams syndrome

Question 7

Thymic aplasia + parathyroid aplasia + cardiac defects

Answer 7

DiGeorge

Question 8

Microcephaly + severe intellectual disability + high-pitched crying + VSD + epicanthal folds

Answer 8

Cri-du-chat

Question 9

DiGeorge and velocardiofacial syndromes are due to abnormal development of:

Answer 9

3rd and 4th pharyngeal pouches

Question 10

What causes the hypercalcemia in Williams syndrome?

Answer 10

Sensitivity to vitamin D

Question 11

Extreme friendliness with strangers

Answer 11

Williams syndrome (microdeletion of long arm of chromosome 7)

Question 12

Cleft lip/palata + cardiac defects + abnormal facies

Answer 12

Velocardiofacial syndrome