Genetic Counseling Boards Review
Questions and Answers 100% (summer
2023/24).
A young patient (5yrs) presents for the first time to a new dentist with crowded teeth,
making them very hard to clean. In further exploration of the issue, she learns that the
child had delayed eruption of his teeth. The patient's mother also relays that her
pediatrician has several times noted how prominent the veins of his scalp are and his
short stature. However, she thinks that this is just part of the spectrum seen in their
family given that she herself is quite short and has fair skin, making it easier to see her
veins. You speak with the dentist who isn't sure whether or not to refer the family. You
are most concerned about what mutation:
LMNA G1138A
LMNA G608G
FGFR3 Exon 11 deletion
FGFR3 G608G - Correct Answer LMNA G608G
The current prenatal screening test used in your clinic has a sensitivity of 96% and a
specificity of 89%. In speaking to representatives from the lab, you learn that they want
to adjust their reading of this test by increasing the cutoff levels. Which of the following
effects would you expect to see if this change was implemented?
i. Increase sensitivity
ii. Increase specificity
iii. Decrease false positives
iv. Decrease false negatives - Correct Answer ii, iii
Which of the following scenarios would MTHFR testing be appropriate?
a. Recurrent pregnancy loss
b. Thrombophilia, in the presence of negative primary thrombophilia testing
c. Open neural tube defect identified on prenatal ultrasound, despite adequate folic acid
intake
d. Patients about to start a methotrexate chemotherapy regimen
e. none of the above - Correct Answer None of the above are reasons that MTHFR
testing should be conducted
Genetic drift is an exception of which of the following assumptions of Hardy Weinberg:
a. No mutation
b. No migration
c. Population is infinitely large
d. Random mating - Correct Answer c
For which indication would telehealth service delivery model be inappropriate?
,Breast cancer
Marfan Syndrome
Carrier screening
Cascade testing - Correct Answer Marfan Syndrome (utility of testing influenced by
physical evaluation)
A couple is seen for preconception counseling. The woman's brother has Gaucher
disease, and she has Ashkenazi Jewish ancestry (Gaucher disease incidence of 1 in
1,000). Before doing any genetic testing, which of the following is closest to the risk of
the couple having an affected child?
1/50
1/100
1/150
1/200 - Correct Answer 1/100
--With incidence of disease in AJ being 1/1000, man's carrier risk is about 1/18
--Woman's risk of being a carrier is 2/3 since her parents are obligate carriers and she is
not affected
-- ⅔ x ½ x 1/18 x ½ = 1/108 = ~1/100
You are meeting a 3 year old little boy in the pediatric genetics clinic. His parents were
referred to the clinic by his astute dentist who mentioned he did not have as many teeth
as expected. On meeting the boy, you also note he has sparse hair. His parents also tell
you he tends to get overheated when he plays outside. Based on these findings, what is
the most likely genetic cause of his signs and symptoms?
a. Missense mutation in IKBKG
b. Deletion in OCA2
c. Missense mutation in EDA1
*The condition being described is hypohidrotic ectodermal dysplasia which is most often
caused by EDA1 mutations.
d. Translocation interrupting SPRED1 - Correct Answer c. Missense mutation in EDA1
*The condition being described is hypohidrotic ectodermal dysplasia which is most often
caused by EDA1 mutations.
A genetic counselor in the ophthalmology clinic is meeting with a family who have a 12
year old son recently diagnosed with retinitis pigmentosa. Throughout the appointment,
the patient's father makes disparaging remarks about blindness and his son being
handicapped. The genetic counselor finds herself to be annoyed and angry with the
father. The genetic counselor has a good friend with RP and she can't help but think
about him as she talks with the family. What best describes the behavior and feelings of
the genetic counselor?
a. Transference
b. Countertransference
c. Resistance
d. Resentment - Correct Answer b. Countertransference *The GC is displaying
countertransference as she is transferring her feelings and experiences with RP in her
friend onto the client/the family.
,You are meeting with a 30 year old woman to discuss a family history of reported Alport
syndrome. She is hoping to start a family in the near future and wishes to know her risk
to have a child with the condition. After taking the family history, you notice that only
males are affected and there is no male-male transmission. The patient's maternal
uncle is affected. Based on this family history, what is the highest recurrence risk you
would quote for this patient to have a child with Alport syndrome?
a. 50%
b. 25%
c. 12.5%
d. Less than 1% - Correct Answer c. 12.5%
Alport syndrome can be XLR, AD or AR. However, the most common form and the form
consistent with the pedigree is XLR. This means for the woman's mom, there is a 50%
chance she is a carrier. She has a 50% chance of passing on that X to the patient. The
patient has a 50% chance of passing that onto the future child. Note, that because it's X
linked, females with the condition may or may not manifest in symptoms.
½ * ½ *½ = ⅛ or 12.5%
A 12 year old female is referred to genetics after her PCP finds 5 café au lait spots on
physical exam. She also has freckling in her armpits. Which of the following clinical
findings would be most helpful for diagnosing her?
a. Learning disability
b. Lisch nodules
c. ADHD
d. Polydactyly - Correct Answer b. Lisch nodules. Learning disabilities and ADHD can
be seen in Legius and NF1, lisch nodules are the most common clinic sign of NF1 and
do not occur in NF2 or Legius, polydactyly is a key feature of any of these conditions
A 15 year old female is referred to genetics for ataxia. Which of the following clinical
findings would be most helpful for diagnosing her?
a. Oculomotor apraxia
b. If she currently uses a wheelchair
c. If she has ocular telangiectasias
d. When her ataxia began - Correct Answer c. If she has ocular telangiectasias. Ocular
telangiectasias and ataxia are features of AT and help distinguish this condition from
ataxia with oculomotor apraxia
A 1 year old girl is referred to pediatrics clinic due to a skin rash that began as many
blisters and slowly changed. It not appears as hypopigmentation that follows the lines of
blaschko. After taking the family history you find that she has an 11 year old paternal
half sister who presented with the same symptoms as an infant. She currently has hypo
and hyperpigmented skin, problems with her eyes and a learning disability. What is the
most likely pattern of inheritance in this family?
a. Autosomal Recessive
b. X linked dominant
, c. X linked recessive
d. Germline mosaicism - Correct Answer d. Germline mosaicism. Rashes that begin as
blisters, change to appear wart like and end in hypo or hyperpigmentation that follows
blaschko's lines are characteristic of incontinentia pigmenti syndrome. This condition
has XLD inheritance BUT this condition is lethal in males in the first trimester. The only
way for dad to pass this on is if he is germline mosaic.
You are seeing a 25y pregnant patient whose partner has renal disease, anterior
lenticonus, and a COL4A5 pathogenic variant. They want to know about the risks to
their children. Which of the following is a true statement:
a. All of their sons will be unaffected
b. All of their daughters will be unaffected carriers
c. Each of their children has a ½ chance of inheriting the mutation
d. Both A and B - Correct Answer a. All of their sons will be unaffected. Firstly,
mutations in COL4A5 cause XL-Alport syndrome (COL4A3 and COL4A4 associated
with AD/AR). Anterior lenticonus =Alport. Both hemizygous males and heterozygous
females with XLAS are at risk for ESRD.
In certain X-linked conditions, 1/3 of isolated males (i.e., no family history) are de novo,
while 2/3 have mothers who are unaffected carriers. Which of the following conditions
does this NOT apply to?
DMD
Lesch-Nyhan syndrome
Fabry
Menkes - Correct Answer c. Males with Fabry can reproduce (and also live long
enough to reach reproductive years). Fabry is usually inherited.
You are seeing a couple for preconception counseling and the family history is
remarkable for consanguinity. They are aware of the potential increased risks for
autosomal recessive conditions and birth defects and have done additional reading on
the topic to prepare their questions for this visit. They want to know (a) how closely they
are related and (b) the probability that their offspring will inherit two copies of an allele
that are the same (IBD). They are half-first cousins.
a. 6.25%; 3.125%
b. 3.125%; 1.5625%
c. 12.5%; 6.25%
d. 3.125%; 6.25% - Correct Answer A. Calculate the coefficient of relationship (r) and
the coefficient of inbreeding (F). r = ½ ^4 (same as for first cousins once removed). F = r
X½.
You are seeing Susie and her partner for a prenatal genetic counseling appointment.
Susie and her partner are overall feeling low stress about the pregnancy but want to
learn more about their risks because of Susie's family history of DMD. Susie had an
uncle who passed from DMD and has no other maternal aunts or uncles. Susie has
three unaffected sons and is currently pregnant with a boy. Susie said her mother never
had genetic testing, but Susie did and is a carrier of DMD.
Questions and Answers 100% (summer
2023/24).
A young patient (5yrs) presents for the first time to a new dentist with crowded teeth,
making them very hard to clean. In further exploration of the issue, she learns that the
child had delayed eruption of his teeth. The patient's mother also relays that her
pediatrician has several times noted how prominent the veins of his scalp are and his
short stature. However, she thinks that this is just part of the spectrum seen in their
family given that she herself is quite short and has fair skin, making it easier to see her
veins. You speak with the dentist who isn't sure whether or not to refer the family. You
are most concerned about what mutation:
LMNA G1138A
LMNA G608G
FGFR3 Exon 11 deletion
FGFR3 G608G - Correct Answer LMNA G608G
The current prenatal screening test used in your clinic has a sensitivity of 96% and a
specificity of 89%. In speaking to representatives from the lab, you learn that they want
to adjust their reading of this test by increasing the cutoff levels. Which of the following
effects would you expect to see if this change was implemented?
i. Increase sensitivity
ii. Increase specificity
iii. Decrease false positives
iv. Decrease false negatives - Correct Answer ii, iii
Which of the following scenarios would MTHFR testing be appropriate?
a. Recurrent pregnancy loss
b. Thrombophilia, in the presence of negative primary thrombophilia testing
c. Open neural tube defect identified on prenatal ultrasound, despite adequate folic acid
intake
d. Patients about to start a methotrexate chemotherapy regimen
e. none of the above - Correct Answer None of the above are reasons that MTHFR
testing should be conducted
Genetic drift is an exception of which of the following assumptions of Hardy Weinberg:
a. No mutation
b. No migration
c. Population is infinitely large
d. Random mating - Correct Answer c
For which indication would telehealth service delivery model be inappropriate?
,Breast cancer
Marfan Syndrome
Carrier screening
Cascade testing - Correct Answer Marfan Syndrome (utility of testing influenced by
physical evaluation)
A couple is seen for preconception counseling. The woman's brother has Gaucher
disease, and she has Ashkenazi Jewish ancestry (Gaucher disease incidence of 1 in
1,000). Before doing any genetic testing, which of the following is closest to the risk of
the couple having an affected child?
1/50
1/100
1/150
1/200 - Correct Answer 1/100
--With incidence of disease in AJ being 1/1000, man's carrier risk is about 1/18
--Woman's risk of being a carrier is 2/3 since her parents are obligate carriers and she is
not affected
-- ⅔ x ½ x 1/18 x ½ = 1/108 = ~1/100
You are meeting a 3 year old little boy in the pediatric genetics clinic. His parents were
referred to the clinic by his astute dentist who mentioned he did not have as many teeth
as expected. On meeting the boy, you also note he has sparse hair. His parents also tell
you he tends to get overheated when he plays outside. Based on these findings, what is
the most likely genetic cause of his signs and symptoms?
a. Missense mutation in IKBKG
b. Deletion in OCA2
c. Missense mutation in EDA1
*The condition being described is hypohidrotic ectodermal dysplasia which is most often
caused by EDA1 mutations.
d. Translocation interrupting SPRED1 - Correct Answer c. Missense mutation in EDA1
*The condition being described is hypohidrotic ectodermal dysplasia which is most often
caused by EDA1 mutations.
A genetic counselor in the ophthalmology clinic is meeting with a family who have a 12
year old son recently diagnosed with retinitis pigmentosa. Throughout the appointment,
the patient's father makes disparaging remarks about blindness and his son being
handicapped. The genetic counselor finds herself to be annoyed and angry with the
father. The genetic counselor has a good friend with RP and she can't help but think
about him as she talks with the family. What best describes the behavior and feelings of
the genetic counselor?
a. Transference
b. Countertransference
c. Resistance
d. Resentment - Correct Answer b. Countertransference *The GC is displaying
countertransference as she is transferring her feelings and experiences with RP in her
friend onto the client/the family.
,You are meeting with a 30 year old woman to discuss a family history of reported Alport
syndrome. She is hoping to start a family in the near future and wishes to know her risk
to have a child with the condition. After taking the family history, you notice that only
males are affected and there is no male-male transmission. The patient's maternal
uncle is affected. Based on this family history, what is the highest recurrence risk you
would quote for this patient to have a child with Alport syndrome?
a. 50%
b. 25%
c. 12.5%
d. Less than 1% - Correct Answer c. 12.5%
Alport syndrome can be XLR, AD or AR. However, the most common form and the form
consistent with the pedigree is XLR. This means for the woman's mom, there is a 50%
chance she is a carrier. She has a 50% chance of passing on that X to the patient. The
patient has a 50% chance of passing that onto the future child. Note, that because it's X
linked, females with the condition may or may not manifest in symptoms.
½ * ½ *½ = ⅛ or 12.5%
A 12 year old female is referred to genetics after her PCP finds 5 café au lait spots on
physical exam. She also has freckling in her armpits. Which of the following clinical
findings would be most helpful for diagnosing her?
a. Learning disability
b. Lisch nodules
c. ADHD
d. Polydactyly - Correct Answer b. Lisch nodules. Learning disabilities and ADHD can
be seen in Legius and NF1, lisch nodules are the most common clinic sign of NF1 and
do not occur in NF2 or Legius, polydactyly is a key feature of any of these conditions
A 15 year old female is referred to genetics for ataxia. Which of the following clinical
findings would be most helpful for diagnosing her?
a. Oculomotor apraxia
b. If she currently uses a wheelchair
c. If she has ocular telangiectasias
d. When her ataxia began - Correct Answer c. If she has ocular telangiectasias. Ocular
telangiectasias and ataxia are features of AT and help distinguish this condition from
ataxia with oculomotor apraxia
A 1 year old girl is referred to pediatrics clinic due to a skin rash that began as many
blisters and slowly changed. It not appears as hypopigmentation that follows the lines of
blaschko. After taking the family history you find that she has an 11 year old paternal
half sister who presented with the same symptoms as an infant. She currently has hypo
and hyperpigmented skin, problems with her eyes and a learning disability. What is the
most likely pattern of inheritance in this family?
a. Autosomal Recessive
b. X linked dominant
, c. X linked recessive
d. Germline mosaicism - Correct Answer d. Germline mosaicism. Rashes that begin as
blisters, change to appear wart like and end in hypo or hyperpigmentation that follows
blaschko's lines are characteristic of incontinentia pigmenti syndrome. This condition
has XLD inheritance BUT this condition is lethal in males in the first trimester. The only
way for dad to pass this on is if he is germline mosaic.
You are seeing a 25y pregnant patient whose partner has renal disease, anterior
lenticonus, and a COL4A5 pathogenic variant. They want to know about the risks to
their children. Which of the following is a true statement:
a. All of their sons will be unaffected
b. All of their daughters will be unaffected carriers
c. Each of their children has a ½ chance of inheriting the mutation
d. Both A and B - Correct Answer a. All of their sons will be unaffected. Firstly,
mutations in COL4A5 cause XL-Alport syndrome (COL4A3 and COL4A4 associated
with AD/AR). Anterior lenticonus =Alport. Both hemizygous males and heterozygous
females with XLAS are at risk for ESRD.
In certain X-linked conditions, 1/3 of isolated males (i.e., no family history) are de novo,
while 2/3 have mothers who are unaffected carriers. Which of the following conditions
does this NOT apply to?
DMD
Lesch-Nyhan syndrome
Fabry
Menkes - Correct Answer c. Males with Fabry can reproduce (and also live long
enough to reach reproductive years). Fabry is usually inherited.
You are seeing a couple for preconception counseling and the family history is
remarkable for consanguinity. They are aware of the potential increased risks for
autosomal recessive conditions and birth defects and have done additional reading on
the topic to prepare their questions for this visit. They want to know (a) how closely they
are related and (b) the probability that their offspring will inherit two copies of an allele
that are the same (IBD). They are half-first cousins.
a. 6.25%; 3.125%
b. 3.125%; 1.5625%
c. 12.5%; 6.25%
d. 3.125%; 6.25% - Correct Answer A. Calculate the coefficient of relationship (r) and
the coefficient of inbreeding (F). r = ½ ^4 (same as for first cousins once removed). F = r
X½.
You are seeing Susie and her partner for a prenatal genetic counseling appointment.
Susie and her partner are overall feeling low stress about the pregnancy but want to
learn more about their risks because of Susie's family history of DMD. Susie had an
uncle who passed from DMD and has no other maternal aunts or uncles. Susie has
three unaffected sons and is currently pregnant with a boy. Susie said her mother never
had genetic testing, but Susie did and is a carrier of DMD.
