Question 1

Tyrone has Gaucher disease.He receives recombinant glucocerebrosidase every other week in an infusion to prevent the symptoms.This treatment is an example of
A) gene therapy.
B) gene transfer.
C) enzyme replacement therapy.
D) pharmacological chaperone therapy.
E) substrate reduction therapy.

Accepted Answer

Enzyme replacement therapy (ERT) is a treatment in which a missing or deficient enzyme is replaced with a functional one. Recombinant glucocerebrosidase is an example of ERT, and it is used to treat Gaucher disease by replacing the missing enzyme that is responsible for breaking down a certain type of fat in the body. This helps to prevent the buildup of these fats in various organs and tissues, which can cause symptoms such as anemia, bone pain, and organ enlargement.

Question 2

Newborn screening reveals that newborn Jessica has inherited PKU.Her parents are distraught at the diagnosis,but a nutritionist explains that Jessica can be treated,right away.The treatment for PKU is
A) nonheritable gene therapy.
B) heritable gene therapy.
C) exchange of her blood supply.
D) twice daily respiratory therapy, performed by the parents.
E) dietary.

Accepted Answer

The best choice for treatment of PKU is dietary. This involves avoiding foods that are high in phenylalanine and consuming a special formula low in phenylalanine. This will prevent the buildup of toxic levels of phenylalanine in the body, allowing the child to develop normally. Nonheritable and heritable gene therapy are not currently available for PKU, exchange of blood supply is not necessary for treatment, and respiratory therapy is not a treatment for PKU.

Question 3

A genetic counselor might discuss assisted reproductive technologies with a couple who wish to
A) adopt a child.
B) avoid one parent's passing on a disease-causing allele to a child.
C) learn if their fetus has an inherited disease.
D) avoid cancer in their children.
E) have a child who will excel at a particular sport or have a particular talent.

Accepted Answer

Assisted reproductive technologies, such as preimplantation genetic diagnosis and gene editing, can be used to avoid passing on disease-causing alleles to offspring. This is a common reason for genetic counseling. Options A, D, and E are not typically discussed in genetic counseling, and option C may be discussed but is not necessarily the primary reason for seeking counseling.

Question 4

One of the first applications of pharmacogenetics in prescribing drugs is for
A) Accutane, an acne drug.
B) an early pregnancy test kit.
C) Viagra, a drug to treat erectile dysfunction.
D) Warfarin, a blood thinner.
E) a narcotic to treat chronic pain.

Accepted Answer

Warfarin is a blood thinner that has a narrow therapeutic index, meaning that the difference between a therapeutic dose and a toxic dose is small. Pharmacogenetic testing can help identify genetic variations that may affect how an individual metabolizes Warfarin, allowing for personalized dosing to reduce the risk of adverse events such as bleeding.

Question 5

Sheree is referred to a genetic counselor because a cystic fibrosis (CF)test done as a routine part of her prenatal care indicated that she is a carrier of the most common mutant allele.Sheree is stunned,because no one in her family has the disease.She is 26 years old.The genetic counselor would most likely
A) explain autosomal recessive inheritance and suggest that Sheree's husband be tested for CF.
B) explain autosomal dominant inheritance and suggest that Sheree's husband be tested for CF.
C) explain autosomal recessive inheritance and suggest that Sheree's parents be tested for CF.
D) advise Sheree to have amniocentesis to check the fetus for the CF genotype.
E) explain that Sheree is obviously a new mutation and that the likelihood that her husband is too is very low, so there is no concern that the child would be affected.

Accepted Answer

The fact that Sheree is a carrier indicates autosomal recessive inheritance. The genetic counselor would suggest that Sheree's husband be tested for CF to determine if he is also a carrier. If both Sheree and her husband are carriers, there is a 25% chance that their child could inherit two copies of the mutant allele and develop CF. Amniocentesis may be considered later in the pregnancy, but it is not the first recommendation.

Question 6

One of the most important types of information that a patient can bring to an initial appointment with a genetic counselor is
A) her immunization records from childhood.
B) results of a comprehensive lipid profile.
C) results from tests for traits and talents done with a direct-to-consumer genetic testing company using risk figures from genome-wide association studies.
D) the family health history, extending to second degree relatives.
E) a list of the occupations of every family member.

Accepted Answer

The family health history is crucial for a genetic counselor to assess the risk of inherited conditions and diseases within a family. Knowing the health history of second degree relatives, such as grandparents, aunts, and uncles, can provide a more comprehensive understanding of potential genetic risks. Immunization records, lipid profiles, and occupation lists may be important for overall health assessment, but are not as relevant to genetic counseling. Direct-to-consumer genetic testing results may also be useful, but should be interpreted with caution and confirmed by medical-grade testing.

Question 7

Nondirective genetic counseling
A) does not accept health insurance.
B) does not deal with disorders carried on the sex chromosomes.
C) is provided by a counselor who is the same gender as the patient.
D) considers diseases caused by genes that are located throughout the genome.
E) offers options but not opinions.

Accepted Answer

Nondirective genetic counseling is a type of counseling that offers options but not opinions, allowing patients to make their own informed decisions. It does not involve specific gender requirements, deal exclusively with sex-linked disorders, or require patients to pay out of pocket as a result of not accepting insurance. Nondirective genetic counseling considers genetic disorders caused by genes located throughout the genome.

Question 8

The phrase "When you hear hoofbeats,think horses,not zebras" applies to genetics in that
A) horse breeders need to know genetics to select which horses to cross.
B) transgenic zebras may have horse genes.
C) transgenic horses may have zebra genes.
D) syndromes with seemingly unrelated symptoms are often inherited.
E) inherited diseases are very rare compared to other types of diseases.

Accepted Answer

The answer of The phrase "When you hear hoofbeats,think horses,not...

Question 9

Which of the following might a genetic counselor do as part of her job?
A) order prenatal tests, interpret the results, and then deliver the baby
B) order a lipid profile, interpret the results, then prescribe a statin drug if cholesterol levels are unhealthy
C) require a patient to take a test for hereditary colon cancer
D) explain the inheritance of a specific disorder in a family, evaluate risks for relatives, and advise on genetic testing
E) take a DNA sample, extract and amplify the DNA, perform specific tests on the genome or sequence all of it, and explain the results to the patient

Accepted Answer

Genetic counselors are trained to evaluate the risk of a genetic disorder and advise patients and their families on genetic testing options. They do not order prenatal tests, deliver babies, prescribe medication, or perform DNA testing themselves. They may require a patient to take a genetic test if it is relevant to the patient's family history and medical condition.

Question 10

Genetic counseling to help patients with Huntington disease in their families decide if they wish to be tested generally
A) explains that testing for adult-onset dominant disorders is not available.
B) takes one or two visits.
C) takes several months.
D) advises all such individuals not to have children.
E) occurs after the person has taken the test for the mutation.

Accepted Answer

Genetic counseling to help patients with Huntington disease in their families decide if they wish to be tested typically takes several months. The process includes education about the disease, discussion of personal and family history, exploration of emotional concerns, and consideration of the possible ramifications of testing. The decision to be tested or not is ultimately up to the individual and their family. Testing for Huntington disease is available and can be done through a blood test, but individuals need to weigh the benefits and potential consequences of knowing their genetic status before proceeding with testing. There is no universal recommendation for all individuals carrying the mutation to not have children, but the decision should be made based on individual circumstances and preferences.

Question 11

Maxwell needs to take an anti-depressant drug.He enrolls in a clinical trial to detect genetic variants and gene expression profiles associated with response to various drugs.This approach to selecting a therapeutic drug is called
A) pharmacogenetics.
B) pharmacophenetics.
C) pharmacogenomics.
D) pharmacology.
E) recombinant DNA technology.

Accepted Answer

Pharmacogenomics involves studying how genes affect a person's response to drugs, including identifying genetic variants and gene expression profiles that can predict an individual's response to specific medications. Therefore, Maxwell's enrollment in a clinical trial to detect genetic variants and gene expression profiles associated with response to various drugs is an example of pharmacogenomics. Choice A) pharmacogenetics is a related field that focuses specifically on how genetic variations affect drug response. Choice B) pharmacophenetics is not a commonly used term in the field, and its meaning is unclear. Choice D) pharmacology is the study of drugs in general and does not specifically address individual responses to medications. Choice E) recombinant DNA technology involves altering genetic material in order to produce specific molecules, such as proteins, and is not directly related to selecting therapeutic drugs based on an individual's genetics.

Question 12

Newborn screening using tandem mass spectrometry identifies certain single-gene disorders by detecting
A) the causative mutation.
B) the wild type gene sequence.
C) an unusual metabolite or metabolic imbalance.
D) abnormal proteins in urine.
E) genome sequences.

Accepted Answer

Newborn screening using tandem mass spectrometry identifies certain single-gene disorders by detecting an unusual metabolite or metabolic imbalance. This is because certain genetic disorders lead to the accumulation or deficiency of specific metabolites, which can be detected through mass spectrometry.

Question 13

Macy has BRCA1 breast cancer.Her sister Philene is healthy,but wants to know if she has inherited the BRCA1 mutation that could make her develop cancer.She is a candidate for a
A) newborn screen.
B) carrier screen.
C) genome screen.
D) predisposition test.
E) genome-wide association study.

Accepted Answer

The best choice for Philene would be a predisposition test. This type of test specifically looks for mutations in genes that increase the risk of developing certain diseases, such as BRCA1 mutations in breast cancer. A carrier screen is used to identify carriers of genetic disorders that can be passed on to children, but it does not necessarily identify an individual's own risk for developing a disease. A genome screen and genome-wide association study are more comprehensive tests that look at an individual's entire genome and are typically used for research purposes rather than clinical decision-making. A newborn screen is performed shortly after birth to identify certain genetic disorders that require early medical intervention.

Question 14

Nonheritable gene therapy is performed on _______ cells.
A) germline
B) somatic
C) constitutional
D) bacterial
E) gametic

Accepted Answer

Nonheritable gene therapy targets somatic cells, which are cells that are not involved in creating offspring (unlike germline cells, which could pass on genetic changes to future generations). Somatic cells include all cells in the body except for the reproductive cells (i.e. sperm and egg).

Question 15

Pharmacological chaperone therapy
A) restores proper folding to a misfolded protein.
B) restores the double helix to opened-up DNA.
C) restores the sugar-phosphate background to the DNA of a specific gene.
D) provides a drug that accompanies a specific mutation, correcting it.
E) replaces a missing enzyme.

Accepted Answer

Pharmacological chaperone therapy involves the use of small molecules that can bind to and stabilize a misfolded protein, thereby restoring its proper folding and function. This approach can be used to treat certain genetic disorders caused by mutations that result in protein misfolding, such as cystic fibrosis and Fabry disease. The other choices mentioned are not relevant to pharmacological chaperone therapy.

Question 16

Diagnosis of hereditary hemochromatosis cannot be based on the results of a genetic test alone because
A) the disease is non penetrant.
B) genetic tests are untrustworthy.
C) the disease is genetically heterogeneic.
D) the disease is not inherited.
E) the genotype changes as a person ages, especially in women.

Accepted Answer

Hereditary hemochromatosis is an autosomal recessive disorder with variable penetrance, meaning not all individuals with the genetic mutation will express the disease phenotype. Therefore, a genetic test alone cannot confirm the presence of the disease without considering clinical symptoms and other diagnostic tests.

Question 17

A test offered on the Web by a direct-to-consumer genetic testing company genotypes a gene for ability to taste bitter substances.This test is not regulated by the Clinical Laboratory Improvement Amendments (CLIA)because
A) the test is not expensive.
B) the test provides information, not a diagnosis.
C) the test is offered in a state of the U.S. not covered by these regulations.
D) the Genetic Information Nondiscrimination Act outlawed CLIA.
E) it is not accurate.

Accepted Answer

According to the Clinical Laboratory Improvement Amendments (CLIA) regulations, a genetic test that provides information about an individual's health but does not provide a diagnosis is not considered a "clinical laboratory test" and therefore is not subject to CLIA regulation. As the test in this case genotypes a gene for ability to taste bitter substances, it only provides information and does not provide a diagnosis, so it is not regulated by CLIA.

Question 18

The field of genetic counseling began when the term was coined
A) in 1986, when the human genome project was first suggested.
B) in 2001, when the first draft of the human genome was published.
C) in 1947, to help physicians explain inherited diseases to their patients.
D) in 1953, when Watson and Crick discovered the structure of DNA.
E) in 1865, when Gregor Mendel published his work on inheritance patterns in pea plants.

Accepted Answer

The field of genetic counseling originated in 1947 to assist physicians in explaining inherited diseases to their patients, particularly with regard to the risks of passing genetic disorders on to their children. The term "genetic counseling" was first used by Sheldon Reed and colleagues in a 1947 paper titled "Genetic counseling" in the American Journal of Human Genetics.

Question 19

Rita has been diagnosed with Her2 breast cancer,and is prescribed Herceptin.The approach of basing a drug prescribing decision on the results of a single-gene test is called
A) pharmacogenetics.
B) pharmacophenetics.
C) pharmacogenomics.
D) pharmacology.
E) enzyme replacement therapy.

Accepted Answer

Pharmacogenetics is the study of how a person's genetic makeup affects their response to drugs, often involving single-gene tests to guide drug prescribing decisions.

Question 20

Enzyme replacement therapy treats
A) the genotype.
B) the genome.
C) protein folding.
D) the phenotype.
E) the genetic code.

Accepted Answer

Enzyme replacement therapy is a medical treatment where an enzyme that is either absent or not functional in a patient is replaced with a functional enzyme. This therapy is intended to treat the phenotypic symptoms caused by the enzyme deficiency. Therefore, the correct answer is D, the phenotype.

Quiz 20: Genetic Testing and Treatment

Tyrone has Gaucher disease.He receives recombinant glucocerebrosidase every other week in an infusion to prevent the symptoms.This treatment is an example of

Newborn screening reveals that newborn Jessica has inherited PKU.Her parents are distraught at the diagnosis,but a nutritionist explains that Jessica can be treated,right away.The treatment for PKU is

A genetic counselor might discuss assisted reproductive technologies with a couple who wish to

One of the first applications of pharmacogenetics in prescribing drugs is for

One of the most important types of information that a patient can bring to an initial appointment with a genetic counselor is

Nondirective genetic counseling

The phrase "When you hear hoofbeats,think horses,not zebras" applies to genetics in that

Which of the following might a genetic counselor do as part of her job?

Genetic counseling to help patients with Huntington disease in their families decide if they wish to be tested generally

Maxwell needs to take an anti-depressant drug.He enrolls in a clinical trial to detect genetic variants and gene expression profiles associated with response to various drugs.This approach to selecting a therapeutic drug is called

Newborn screening using tandem mass spectrometry identifies certain single-gene disorders by detecting

Macy has BRCA1 breast cancer.Her sister Philene is healthy,but wants to know if she has inherited the BRCA1 mutation that could make her develop cancer.She is a candidate for a

Nonheritable gene therapy is performed on _______ cells.

Pharmacological chaperone therapy

Diagnosis of hereditary hemochromatosis cannot be based on the results of a genetic test alone because

A test offered on the Web by a direct-to-consumer genetic testing company genotypes a gene for ability to taste bitter substances.This test is not regulated by the Clinical Laboratory Improvement Amendments (CLIA) because

The field of genetic counseling began when the term was coined

Rita has been diagnosed with Her2 breast cancer,and is prescribed Herceptin.The approach of basing a drug prescribing decision on the results of a single-gene test is called

Enzyme replacement therapy treats