Division of Genetics and Metabolism

Test module: Diagnostic Testing of Hearing Loss

Estimated time to complete: 6 min.
Number of questions: 6

Your name:

1. What percent of all newborns identified with hearing loss is due to genetic cuasation?

15%
30%
60%
90%

Note: You must check your answer after each selection.

2. A CT scan of the inner ear that deomonstrated enlargement of the vestibular aqueduct is most suggestive of

CHARGE syndrome
Pendred syndrome
Connexin-26 condition
Waardenburg syndrome

3. Of autosomal recessive causes of hearing loss, which is correct

Connexin-26 defects account for 5% of cases
More than 1000 differenct genes have been identified
Other that connexin-26, there is no other gene that accounts for more than 3% of cases
Five genes account for 80% of cases

4. Which factor not important in determining the genetic type of hearing loss

Prelingual versus post lingual onset
conductive versus sensorineural hearing loss
inner ear structure
birth weight and gestational age
sex of the child

5. The most comment postive gene test in a deaf newborn will be:

Connexin-26
Connexin-43
SLCA26
PAX6

6. DNA screening for multiple genes that cause autosomal recessive hearing loss is not yet available because

There are not enough genes to screen for
Other testing methods are as cost effective
Technical advances are still needed to test this large number of genes
Ethics restrictions do not allow such testing

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