Deck 8: Genetic Testing and Prenatal Diagnosis

Question 1

Which of the following statements about PKU is FALSE?

A) A mutation in the PAH gene on chromosome 12 causes PKU.
B) PKU is one of the few genetic conditions that has a treatment.
C) PKU is influenced by both genetics and the environment.
D) PKU is inherited as an autosomal dominant trait.
E) People with PKU cannot convert phenylalanine to tyrosine.

Answer 1

D

Question 2

Amniocentesis is recommended when the mother is 35 years or older.This is because after age 35,

A) the mother's health will be severely impacted with each pregnancy.
B) she is more likely to have a female child.
C) the risk of the child having an X-linked disorder increases.
D) the mother's chromosomes are likely to suffer some damage.
E) the risk of having a child with a chromosomal abnormality increases dramatically.

Answer 2

E

Question 3

Prenatal genetic testing is performed

A) in order to understand developmental disorders.
B) to detect genetic disorders and birth defects in the developing fetus.
C) to identify if an individual will develop a genetic disorder in midlife.
D) to understand patterns of inheritance.
E) to determine if the parents are carriers of disease alleles.

Answer 3

B

Question 4

What is the genetic defect responsible for PKU?

A) A mutation in the PAH gene causes the body to break down phenylalanine more rapidly than normal.
B) A mutation in the PAH gene inactivates the phenylalanine hydroxylase enzyme.
C) A mutation in the PAH gene causes the body to break down the amino acid tyrosine more rapidly than normal.
D) A mutation in the PAH gene causes the body to break down the amino acid tyrosine more slowly than normal.
E) A mutated protein causes the body to convert tyrosine into phenylalanine.

Question 5

Preimplantation genetic diagnosis (PGD)

A) can be used to detect genetic abnormalities before the oocyte is fertilized.
B) can be used to detect genetic abnormalities before the embryo is implanted in the mother.
C) requires analysis of all of the blastomeres in the early embryo.
D) takes place after in vitro fertilization.
E) depends on direct microscopic analysis of embryonic cells.

Question 6

Prenatal genetic diagnosis is used to determine

A) the fetal genotype.
B) if family members are carriers.
C) if the individual will be completely free of genetic disorders throughout their lifetime.
D) if the parents have a fatal disorder.
E) if the fetus has a functioning kidney.

Question 7

Ultrasound can aid in the diagnosis of

A) monosomy 1.
B) trisomy 21..
C) all genetic disorders.
D) cystic fibrosis.
E) phenylketonuria.

Question 8

Which of the following statements is FALSE regarding CVS?

A) It has a about the same risk of miscarriage as amniocentesis.
B) It can be performed as early as 8-10 weeks of pregnancy.
C) It offers early diagnosis of genetic diseases.
D) It involves recovering fetal cells from the mother's blood.
E) It allows the preparation of karyotypes within a few hours or a few days after harvesting the cells.

Question 9

Ultrasound is a

A) diagnostic procedure used to directly detect DNA mutations.
B) diagnostic procedure used to analyze family history.
C) noninvasive technique used to image the developing fetus.
D) noninvasive technique used to directly detect abnormal chromosomes.
E) diagnostic procedure used to detect early colon cancer.

Question 10

Amniocentesis is typically recommended

A) only if both of the parents have a known chromosomal abnormality.
B) if the mother will be 25 years or older when she gives birth.
C) if the parents have already had a child with a chromosomal abnormality.
D) if the father is affected by an X-linked disorder.
E) anytime a couple is expecting a child.

Question 11

Which of the following situations would place a child at risk to inherit PKU from his or her parents?

A) The father is heterozygous (normal and mutant PAH alleles); the mother is homozygous normal.
B) The mother is heterozygous (normal and mutant PAH alleles); the father is homozygous normal.
C) Both parents are heterozygous (normal and mutant PAH alleles) for the PAH gene.
D) The father is homozygous for the mutant PAH alleles; the mother is homozygous normal.
E) The mother is homozygous for the mutant PAH alleles; the father is homozygous normal.

Question 12

A 30-year-old man comes from a family with a history of Huntington disease.What type of testing should he be considering?

A) Presymptomatic testing
B) Prenatal diagnosis
C) Ultrasonography
D) Carrier testing for his wife
E) Amniocentesis.

Question 13

This type of testing is used to test unaffected members of a family with a history of a genetic disorder such as cystic fibrosis.

A) Presymptomatic testing
B) Prenatal diagnosis
C) Ultrasonography
D) Carrier testing
E) Amniocentesis.

Question 14

Since adult polycystic kidney disease (ADPKD)is a

A) recessive trait, any individual who is heterozygous for the mutant allele will be affected.
B) dominant trait, any individual who is heterozygous for the mutant allele will be affected.
C) X-linked trait, any male who is heterozygous for the mutant allele will be affected.
D) recessive trait, any individual who is homozygous for the mutant allele will be affected.
E) X-linked trait, any female who is heterozygous for the mutant allele will be affected.

Question 15

A woman with PKU becomes pregnant.During her pregnancy,she should

A) eat and drink foods containing lots of phenylalanine.
B) take tyrosine supplements.
C) find out if her partner is a carrier.
D) follow a strict diet avoiding phenylalanine.
E) do nothing special.

Question 16

Which of the following statements about adult polycystic kidney disease (ADPKD)is FALSE?

A) Treatment options include kidney dialysis or transplantation.
B) There is a presymptomatic genetic test for ADPKD.
C) ADPKD typically affects individuals between the ages of 35-50.
D) ADPKD affects about 1 in 1,000 individuals.
E) Most individuals with ADPKD receive a kidney transplant.

Question 17

Genetic testing can be used to identify all of the following EXCEPT those individual who

A) carry a genetic disease allele.
B) are at risk of having a child with a genetic disorder.
C) may have a genetic susceptibility to drugs.
D) may have a genetic susceptibility to environmental agents.
E) will definitely develop cancer in their lifetime.

Question 18

This type of testing is usually used to identify individuals who will develop disorders in midlife.

A) Presymptomatic testing
B) Prenatal diagnosis
C) Ultrasonography
D) Carrier testing
E) Amniocentesis.

Question 19

What is the mode of inheritance for PKU?

A) autosomal dominant
B) autosomal recessive
C) X-linked recessive
D) X-linked dominant
E) The mode of inheritance for PKU has not yet been determined.

Question 20

Recovering fetal cells present in the mother's blood can be difficult because

A) only 1 in every 100,000 cells in the mother's blood is a fetal cell.
B) this technique increases the risk of miscarriage.
C) the fetal cells lack a nucleus.
D) fetal cells do not enter the mother's blood stream.
E) these cells have not been useful for diagnosing genetic disorders.

Question 21

In 1972,Congress passed a law that established a screening program to identify carriers of sickle cell anemia.

Question 22

MATCHING
Match the appropriate term with the description.
a.Sonar imaging of a fetus
b.Treatments include dialysis
c.Carriers were prevented from joining the United State Air Force
d.Analyzes DNA present in amniotic fluid
e.Procedure where a needle is inserted through the abdominal and uterine wall
f.Leads to death by age 3 or 4
g.Blastomere genetic testing
h.Can be done at 8-10 weeks of pregnancy
i.Treatment involves avoiding phenylalanine in the diet
ADPKD

Question 23

All of the following are conditions that allow population screenings of carriers EXCEPT

A) the disease must occur mainly in defined populations.
B) tests for carriers must be available.
C) tests for carriers must be fairly inexpensive.
D) there must be several options for at-risk couples to have unaffected children.
E) there must be a cure for the disease.

Question 24

Tay-Sachs disease is a fatal ____ trait.

A) autosomal recessive
B) X-linked recessive
C) autosomal dominant
D) X-linked dominant
E) Y-linked

Question 25

Prenatal testing is usually only done to detect genetic disorders in the fetus when there is a risk of such conditions.

Question 26

MATCHING
Match the appropriate term with the description.
a.Sonar imaging of a fetus
b.Treatments include dialysis
c.Carriers were prevented from joining the United State Air Force
d.Analyzes DNA present in amniotic fluid
e.Procedure where a needle is inserted through the abdominal and uterine wall
f.Leads to death by age 3 or 4
g.Blastomere genetic testing
h.Can be done at 8-10 weeks of pregnancy
i.Treatment involves avoiding phenylalanine in the diet
Amniocentesis

Question 27

MATCHING
Match the appropriate term with the description.
a.Sonar imaging of a fetus
b.Treatments include dialysis
c.Carriers were prevented from joining the United State Air Force
d.Analyzes DNA present in amniotic fluid
e.Procedure where a needle is inserted through the abdominal and uterine wall
f.Leads to death by age 3 or 4
g.Blastomere genetic testing
h.Can be done at 8-10 weeks of pregnancy
i.Treatment involves avoiding phenylalanine in the diet
PKU

Question 28

Genetic testing can determine an individual's genotype.

Question 29

Tay-Sachs is an autosomal dominant disorder affecting lysosomes.

Question 30

A couple at risk of having a baby with a genetic disorder may have to choose between aminocentesis and chorionic villus sampling (CVS)for genetic analysis of their fetus.One main advantage CVS has over amniocentesis is CVS

A) does not increase the risk of miscarriage.
B) can provide results much earlier in pregnancy.
C) can provide an actual image of the fetus.
D) provides more genetic information.
E) can be used prior to embryos being implanted in the mother.

Question 31

Which of the following statements about genetic screening programs across the United States is FALSE?

A) The number of disorders screened varies from state to state.
B) The types of disorders screened vary from state to state.
C) Genetic screening programs for newborns are mandated by law.
D) Genetic screening started in the 1960s with screening for PKU.
E) Genetic screening started in the 1970s with screening for Tay-Sachs disease.

Question 32

MATCHING
Match the appropriate term with the description.
a.Sonar imaging of a fetus
b.Treatments include dialysis
c.Carriers were prevented from joining the United State Air Force
d.Analyzes DNA present in amniotic fluid
e.Procedure where a needle is inserted through the abdominal and uterine wall
f.Leads to death by age 3 or 4
g.Blastomere genetic testing
h.Can be done at 8-10 weeks of pregnancy
i.Treatment involves avoiding phenylalanine in the diet
Tay-Sachs

Question 33

In the Ashkenazi Jewish ?community,Tay-Sachs screening programs are combined with counseling sessions to provide information about the risks of having an affected child.

Question 34

The Tay-Sachs screening program has actually led to an increase in the number of children born with the disease.

Question 35

Tay-Sachs disease

A) is inherited as a dominant trait.
B) occurs at a higher frequency among African Americans.
C) affects individuals in adulthood.
D) can lead to deterioration of mental capabilities.
E) can be treated by controlling diet.

Question 36

Genetic testing can be done on fetuses,newborns,children,and adults.

Question 37

Ultrasound can be used to identify fetuses with trisomy 18 because it can directly visualize chromosomes in a cell.

Question 38

Currently,some genetic conditions can be treated,but none can be cured.

Question 39

Some genetic disorders are found in higher frequencies in certain ethnic groups.

Question 40

All individuals with adult polycystic kidney disease (ADPKD)carry two copies of the mutant allele.

Question 41

What are the different types of prenatal tests that can be performed to diagnose genetic disorders? Give at least one advantage and disadvantage of each method.

Question 42

MATCHING
Match the appropriate term with the description.
a.Sonar imaging of a fetus
b.Treatments include dialysis
c.Carriers were prevented from joining the United State Air Force
d.Analyzes DNA present in amniotic fluid
e.Procedure where a needle is inserted through the abdominal and uterine wall
f.Leads to death by age 3 or 4
g.Blastomere genetic testing
h.Can be done at 8-10 weeks of pregnancy
i.Treatment involves avoiding phenylalanine in the diet
Ultrasound

Question 43

MATCHING
Match the appropriate term with the description.
a.Sonar imaging of a fetus
b.Treatments include dialysis
c.Carriers were prevented from joining the United State Air Force
d.Analyzes DNA present in amniotic fluid
e.Procedure where a needle is inserted through the abdominal and uterine wall
f.Leads to death by age 3 or 4
g.Blastomere genetic testing
h.Can be done at 8-10 weeks of pregnancy
i.Treatment involves avoiding phenylalanine in the diet
ffDNA analysis

Question 44

Distinguish between genetic testing and genetic screening.

Question 45

MATCHING
Match the appropriate term with the description.
a.Sonar imaging of a fetus
b.Treatments include dialysis
c.Carriers were prevented from joining the United State Air Force
d.Analyzes DNA present in amniotic fluid
e.Procedure where a needle is inserted through the abdominal and uterine wall
f.Leads to death by age 3 or 4
g.Blastomere genetic testing
h.Can be done at 8-10 weeks of pregnancy
i.Treatment involves avoiding phenylalanine in the diet
CVS

Question 46

What are the genetic and biochemical basis for PKU? What type of treatment is recommended for individuals diagnosed with the disease? Explain why mandatory screening for PKU exists in every state and is considered to be ethically appropriate,while this is not the case for screening for other genetic conditions.

Question 47

MATCHING
Match the appropriate term with the description.
a.Sonar imaging of a fetus
b.Treatments include dialysis
c.Carriers were prevented from joining the United State Air Force
d.Analyzes DNA present in amniotic fluid
e.Procedure where a needle is inserted through the abdominal and uterine wall
f.Leads to death by age 3 or 4
g.Blastomere genetic testing
h.Can be done at 8-10 weeks of pregnancy
i.Treatment involves avoiding phenylalanine in the diet
PGD

Question 48

Compare and contrast amniocentesis and chorionic villus sampling (CVS).

Question 49

MATCHING
Match the appropriate term with the description.
a.Sonar imaging of a fetus
b.Treatments include dialysis
c.Carriers were prevented from joining the United State Air Force
d.Analyzes DNA present in amniotic fluid
e.Procedure where a needle is inserted through the abdominal and uterine wall
f.Leads to death by age 3 or 4
g.Blastomere genetic testing
h.Can be done at 8-10 weeks of pregnancy
i.Treatment involves avoiding phenylalanine in the diet
Sickle cell

Question 50

Currently there are no programs requiring that people be tested to see if they are carriers for a genetic disease.If this changed,would you support such a policy? Why or why not? Include arguments both for and against such a policy.

Question 51

As more disease-related genes are located and characterized,and increased genetic screening becomes available,what changes,if any,do you think will occur in the human population's gene pool? Provide examples.