genetic testing and counseling

Question 1

assortative mating

Answer 1

mating of people that have the same phenotype results in more of the phenotype to be present
-i.e. within the Deaf community, when two deaf individuals mate this results in more deaf people being born

Question 2

linguistic homogamy

Answer 2

mating between individuals that have the same language as native signers
-prime example if within the Deaf community and using ASL

Question 3

founder effect

Answer 3

has common ancestors
-consanguinity creates a small gene pool, there will be carriers and then an individual will need 2 bad identical genes

Question 4

population bottleneck

Answer 4

reduction in population size, which enhances the effects of gene drift

Question 5

gene drift

Answer 5

random fluctuations in the numbers of gene variants in a population

Question 6

balanced polymorphism

Answer 6

a process of natural selection where different alleles of a gene provide advantages in different environments or under different circumstances.

• heterozygous for a certain disease leads to protection from other diseases
  -being homozygous for the disease (with showing phenotype or not) does not protect you

Question 7

identification of affected individuals

Answer 7

-perinatal history (what happens in the first month of life)
-speech and language milestones
-history of poor motor development
-family history
-physical examination
-audiologic examination
-laboratory tests
-endocrine function
-electrocardiagram
-radiology

Question 8

thyroid symptoms in children may indicate___

Answer 8

pendreds syndrome

Question 9

visual and or vestibular abnormalities in kids may indicate

Answer 9

Ushers

Question 10

history or presence of pigmentary abnormalities of children with HL may indicate______

Answer 10

waardenburg syndrome

Question 11

Presence of branchial clefts/sinuses in children may indicate

Answer 11

BOR

Question 12

know factors within the perinatal history

Answer 12

low birth weight, time spent in NICU, certain infection, use of ototoxic medication or hypoxia

Question 13

know factors within family history

Answer 13

family history of HL or deafness (in particular within young age), consanguinity, progressive HL

Question 14

screening vs. diagnostic

Answer 14

screening: identity’s people with a high risk of having a specific genetic disorder
diagnostic: test performed that confirm or exclude a known/suspected genetic disorder

Question 15

genetic testing involves …

Answer 15

detailed clinical and family history and a comprehensive examination of the patient and family if necessary

Question 16

process of diagnosing a child with HL

Answer 16

NBHS, confirmation of HL, getting a family history, ENT/audiology/genetic evaluation, then molecular testing if applicable

Question 17

best way to genetically diagnose a child with HL

Answer 17

-testing for GJB2 due to it being the most common
-otoSCOPE (can test for 152 genes known to cause HL and other syndromes
-FISH: identifies chromosome structures ; chromosomal anomalies

Question 18

how to test for mitochondrial mutations

Answer 18

DNA sample for genetic testing can be obtained from any tissue
-families with a maternal line of inheritance, individuals from high risk families, individuals from high risk ethnic groups and all infants admitted to the NICU should be tested

Question 19

what to do when diagnosing a child with HL

Answer 19

detailed family history, consider genetic etiology, rule out syndromic HL, DNA testing for GJB2/6 genes and temporal bone imaging to rule out EVA

Question 20

what not to due when diagnosing a child with HL

Answer 20

don’t call it sporadic or environmental, don’t quote a negligible recurrence rate and don’t offer a molecular panel for HL at the outset

Question 21

what are some benefits to identifying genetic condition

Answer 21

-accurate diagnosis and prognosis
-can remove the blame game
-can recognize the risk of other anomalies
-can recognize the risk of other developmental handicaps
-can provide accurate recurrence for risk

Question 22

what are some issues related to genetic testing

Answer 22

-it is not sensitive to all genes
-provides information about reproductive choices
-provides information about biologic relatives
-can show misassigned paternity
-insurance discrimination
-Deaf community has a negative attitude towards it except with Ushers syndrome

Question 23

genetic counseling

Answer 23

ensures those that received genetic testing has a clear understanding of its meaning, including the risks
-pre-test and post-test are of equal importance

Question 24

what is the role of an audiologist with genetic counseling

Answer 24

we do on undertake genetic counseling however if a genetic component is suspected we should refer out with reason