Download Final Exam Medical Genetics Test A SINGLE BEST ANSWER 1

Final Exam Medical Genetics Test A
SINGLE BEST ANSWER
1. Which of the following factors distinguish an autosomal dominant trait limited to males from an Xlinked recessive trait?
A) Only males usually show the complete manifestations
B) Affected males have unaffected mothers
C) Affected sons may have affected fathers
D) Females may show mild features of the trait
E) Causative mutations may arise in males or females
2. The best definition of DNA fingerprinting (also known as DNA typing) is:
A) use of variable number tandem repeat analysis for the identification of individuals
B) currently relevant methods of genome sequence analysis for the identification and
prosecution of guilty individuals
C) establishment of a database allowing for statistical estimation of identity between two
biological samples
D) recognition of phenotypic variation among individuals
E) the use of genetic variation, detected in DNA from a biological sample, to establish a
biological relationship
3. A couple comes to the office with their third pregnancy. They are both white and 37 years old. After
discussing the risk of chromosome anomalies in babies of `older mothers', you counsel about screening
them for cystic fibrosis carrier status. You do this because:
A) the risk of autosomal recessive diseases increases with increasing paternal age
B) the risk of autosomal dominant diseases increases with increasing paternal age
C) it is an easy test of near 100% accuracy and you think everyone should have it
D) the couple is at significant risk for carrying cystic fibrosis because of their ethnic group
E) the lab is testing a new procedure and they need more patient samples
4. The "two-hit" hypothesis of the origin of cancer:
A) was first described in Wilm's tumor
B) describes how mutation of an oncogene results in cancer
C) explains why tumors are frequently present in both eyes of patients with the familial
form of retinoblastoma and only one eye of patients with sporadic retinoblastoma
D) states that loss of one copy of a tumor suppressor gene result in tumor formation
E) explains why breast cancer occurs in 1 of 8 women
5. Monozygous twin females have the greatest likelihood for an extremely discordant phenotype for:
A) Cystic Fibrosis
B) Polyposis of the colon
C) Hurler Syndrome
D) Duchenne Muscular Dystrophy
E) Achondroplasia
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6. The best definition of the difference between a Genetic Map and a Physical Map is.
A) A physical map is a collection of markers statistically related and a genetic map consists
of pieces of chromosomes or genes.
B) A genetic map is based upon linkage studies and a physical map takes advantage of the
genetic engineering of other organisms
C) A genetic map is microscopic and a physical map is macroscopic
D) A physical map is more useful for loci that are far apart and a genetic map is more useful
for loci that are close together
E) A physical map uses monoclonal antibodies and a genetic map uses protein subunits
7. Restriction fragment length polymorphisms (RFLPs) result from DNA variation that affects cleavage
sites for restriction endonucleases. In order for RFLPs to be useful in diagnosis for a genetic disorder.
A) they must be within or closely linked to the disease-causing gene locus
B) they must be associated with a cytogenetically visible chromosome abnormality
C) they must be the causative mutation for the disorder
D) they must result from digestion of DNA with EcoRI
E) they must be consistent in size from family to family
8. Therapeutic abortions can be performed legally in Texas in the first two trimesters of pregnancy (to 24
weeks gestation). Prenatal testing ideally is performed in such a way that results are available before 24
weeks gestation so an elective termination may still be done if there is an abnormality. Keeping this in
mind, fetal echocardiograms are generally not done before 22 weeks gestation because:
A) the heart is not completely formed until that time
B) anmiocentesis is typically done at 15-18 weeks, and those result must be back, first
C) structural congenital heart disease is never fatal
D) the time maximizes the ultrasound resolution of the heart
E) the American College of Obstetricians and Gynecologists sets 22 weeks as the date of
this screening test for all women.
9. Changes in the DNA base pair sequence are fairly common. Most nucleotide changes do not produce
disease in live-born humans because:
A) they are incompatible with early human embryogenesis
B) they happen in parts of the genome that are nonessential
C) they are more frequently beneficial than deleterious
D) they are recessive to the normal nucleotide sequence
E) they are corrected by the DNA repair mechanisms before the fetal period
Questions 10 and 11:
A man and a woman who both have albinism (absence of pigment) are contemplating marriage
and want to know the risk for their potential children to have albinism. You look up the condition
in the Clinical Genetics book and discover that there are two types of albinism caused by separate
genetic loci. Both are autosomal recessive traits, but one is characterized by absent activity of the
enzyme tyrosinase, while enzyme activity is normal in the other form. You tell them that they
should be tested for tyrosinase activity.
10. If both lack tyrosinase activity, the risk for their offspring to be affected is:
A) Negligible
B) 25%
C) 50%
D) 75%
E) 100%
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11. If one has normal tyrosinase activity and the other lacks it, the risk for their offspring to be
affected is:
A) Negligible
B) 25%
C) 50%
D) 75%
E) 100%
Questions 12
A woman knows that she is a carrier for Fragile X 'syndrome. She is interested in knowing what
son of prenatal diagnostic tests are of the most use to her for evaluating her next pregnancy. She
is interested in a test that can be done with the highest accuracy for Fragile X as early in the
pregnancy as possible. She is not currently pregnant.
12. The laboratory test(s) of choice is (are):
A) Karyotypic analysis of the X chromosome for the fragile site
B) Alphafetoprotein, human chorionic gonadotropic and unconjugated estriol
C) Linkage analysis
D) DNA analysis for the fragile X mutation
E) Interphase fluorescence-in-situ hybridization studies of the X chromosome
13. In Leber hereditary optic neuropathy, all individuals are related through the maternal line. Affected
males cannot pass on the disease. The most likely mechanism for this finding is:
A) Mitochondrial inheritance
B) Imprinting
C) Germline mosaicism
D) Uniparental disomy
E) Variable expressivity
14. Osteogenesis imperfecta, which is characterized by fragile bones, defective teeth and blue
sclerae, may be due to mutations of the alpha 2 chain of type I collagen that interrupt the
triple helix formation. Ehlers-Danlos syndrome type Vii, which is characterized by
extremely loose joints and stretchy skin, may be due to mutations of the alpha 2 chain of
type I collagen that disrupt the conversion of type I procollagen to type I collagen. The
term that has been used to describe this phenomenon is:
A) Homologous recombination
B) Allelic heterogeneity
C) Genetic homogeneity
D) Locus heterogeneity
E) Interallelic variability
15. About 70% of minor malformations involve the:
A) Head and Neck
B) Head and Chest
C) Head and Genitalia
D) Head and Hands
E) Head and Spine
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16. A couple who has just delivered a stillborn infant with multiple defects. Chromosome
analysis reveals a 69,XXX karyotype (triploidy). The family asks about recurrence risk.
You tell them that the chance that their next pregnancy will be similarly affected is:
A) 1-2%
B) 10%
C) 25%
D) negligible (-1:10,000)
E) dependant on the sex of the next pregnancy
17. Oncogenes
A) are normal DNA repair genes
B) cause most hereditary cancers
C) can result from specific chromosome translocations
D) are created by mutating tumor suppressor genes
E) can be activated by losing both copies
18. Cancer is:
A) a disease which uses more than 25% of US health care dollars every year
B) a single disease
C) familial in 95% of cases
D) a multitude of diseases with the common denominator of gene mutation
E) non-clonal in origin
19. If one of the X chromosomes is normally inactivated, why do girls with Turner syndrome
have physical abnormalities?
A) The inactivation often extends to an autosome
B) The inactivation often extends to the active X chromosome
C) Only girls with isochromosome X exhibit abnormalities
D) X inactivation only occurs in germ cells
E) Part of the inactive X chromosome remains active
20. A genetic polymorphism is defined as:
A) a non-disease producing genetic trait seen very rarely in the population
B) a disease-producing genetic trait seen very rarely in the population
C) the presence of more than one allele at a locus with the rarer allele having a frequency
of at least 1%
D) the presence of more than one allele at a locus with the rarer allele having a frequency of no
more than I%
E) the actual observed expression of a gene or pair of genes
21. Which of the following is expected to be phenotypically normal?
A) A female with 46 chromosomes and a Robertsonian translocation between
chromosomes 14 and 21.
B) A female with 46 chromosomes and an isochromosome formed from the long arm of
chromosome 21.
C) A female with 45 chromosomes and a Robertsonian translocation between
chromosomes 15 and 21.
D) A female with the karyotype 47,XX,+21.
E) A male with karyotype 47,XX+2 1.
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22. Cytogenetic studies of soft tissue tumors:
A) are a waste of health care resources
B) how non-specific chromosome changes
C) are virtually never diagnostic
D) can be performed with frozen, fixed, or living tissues
E) can distinguish tumor types when other methods fail
Questions 23-26:
A couple presents because they recently had a son who was healthy at birth but became ill and
died at 3 weeks of age. The hospital records indicate that careful physical exam showed no major
or minor abnormalities, although his urine and breath had a peculiar odor. The family history
reveals that the couple has two healthy daughters but that they also had a third daughter who died
soon after birth under circumstances similar to those of the recent child. There are no other family
members with similar problems. The parents now seek information regarding the most recent
child's illness and the implications for future pregnancies.
23. The infant had a variety of laboratory studies performed; you are most interested in:
A) The karyotype of the child
B) Metabolic studies of the child
C) Metabolic studies of the mother
D) Metabolic studies of the father
E) The autopsy report of the deceased daughter
24. Upon repeated questioning the parents admit that they are second cousins. This makes you
suspect that the deceased child most likely had:
A) A chromosomal disorder
B) An autosomal dominant disorder
C) An autosomal recessive disorder
D) An X-linked recessive disorder
E) None of the above
25. You counsel the couple that their risk for having further children with this condition is:
A) 10% for each pregnancy
B) 25% for each pregnancy
C) 50% for each pregnancy
D) 25% for female children and 50% for male children
E) 25% for male children and 50% for female children
26. The couple asks what the risk of having an affected child is for their healthy daughters.
Assuming they do not marry relatives, their risk is:
A) Negligible
B) 10%
C) 25%
D) 33%
E) 50%
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Questions 27-29
A Hispanic couple is in your office for genetic counseling. The woman is 37 and the man is 39.
There is no known history of a genetic disease in either of their families. The woman is currently
pregnant at an estimated gestational age of 11 weeks. They report that the pregnancy has been
uncomplicated. They are interested in discussing their risk of having a child with a genetic or
congenital abnormality.
27. The indication for genetic counseling is:
A) Advanced maternal age
B) Ethnic risk of chromosomal abnormalities
C) Ethnic risk of hereditary disorders
D) Routine screening for genetic disorders
E) Advanced paternal age
28. They opt for undergoing chorionic villus sampling. The karyotype indicates that the fetus
is a female who has trisomy 13. You convey this information to the parents by:
A) dictating a letter with detailed explanations of trisomy 13 and their available options
B) calling the mother at work so that she'll know as soon as possible
C) calling the obstetrician's office and letting them handle it since they did the chorionic
villus sampling and are responsible for the results
D) calling the couple in the evening to tell them there is an abnormality and making an
appointment for the next morning to discuss it in detail
E) calling the father at work so he can tell the mother
29. The information that the parents need to know immediately includes the lethality of trisomy
13, the fact that they are not at fault for this occurring, and their options with regard to the
pregnancy. They are both educated professionals, and from your point of view the counselling is
straightforward. You assume:
A) nothing
B) they will have a classic grief response
C) they will be rational and logical in their reactions and decisions
D) they will make the same decisions that you would in their place
E) they will understand everything that you tell them
30. The newborn screening test for phenylketonuria has a high rate of false positives. There
are 15 children who test `positive' by the screening test for every 1 child who has true
phenylketonuria. The test parameters are defined this way on purpose because they assure
a good ascertainment rate for the children actually affected, and
A) there is a definitive biochemical test to back up the screening test and eliminate the false
positives
B) for the children who are carriers of the gene
C) there is a definitive mutation test to back up the screening test and eliminate the false
positives
D) for the children who are at risk for neuropathies from aspartamine ingestion
E) it allows for less rigid testing procedures
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Questions 31-33
A 25 year old black woman comes to see you because she is engaged to be married and her
fiancé’s brother has sickle cell anemia. She is concerned about having a child with the same
condition. She is not currently pregnant. She tells you that she and her fiancé are not related, and
that she has sickle cell trait (is a carrier for sickle cell disease).
31. The indication for genetic counseling in this case is:
A) Advanced maternal age
B) Family history of chromosomal abnormality
C) Family history of hereditary disorder
D) Exposure to a known teratogen
E) Prenatal diagnosis
32. The fiance is 27 years old and healthy. You tell her that his risk of being a carrier is 2 out
of 3. The most appropriate next procedure is:
A) to tell her that prenatal diagnosis can be done on either chorionic villus sampling or
amniocentesis
B) to test the fiance and determine his carrier status
C) to suggest racially-selected and sickle cell-screened sperm donation
D) to discuss the medical advances being made in the management of sickle cell disease
E) to refer her to hematology clinic so that they can address her questions
33. Your consultand wants to know the highest risk possible before any investigation
proceeds. You ten her that. since she is a known carrier and her fiance has a 2 out of 3
chance of being a carrier, their highest risk for having a child with sickle cell disease is:
A) 1 out of 50
B) 1 out of 25
C) 1 out of 12
D) 1 out of 6
E) 1 out of 3
Questions 34-35
A woman comes to see you in your office. She knows that some of her family members have
Marfan syndrome. You find out that her father, two of her siblings, and her eldest child have all
been diagnosed with Marfan syndrome.
34. After a thorough exam and testing, you conclude that she shows no features of the
condition. You conclude that:
A) she is nonpenetrant for Marfan syndrome
B) she did not inherit the Marfan gene from her father
C) Marfan syndrome must be autosomal recessive in this family
D) her affected child must represent a new mutation for the condition
E) the family must have been misdiagnosed
35. This woman's risk for having a child affected with Marfan syndrome is
A) near 0%
B) 25%
C) 50%
D) near 100%
E) dependent upon the carrier status of her husband
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36. A couple is known to be at increased risk to have a child with cystic fibrosis because the
wife's sister died of the disease. Their carrier status was checked 6 of years ago,
confirming the presence of a ∆F508 mutation in the wife, but failing to find any mutation in
the husband. Though their first child was healthy, re-testing of the husband was
recommended during their second pregnancy. This recommendation was made because:
A) it is a surreptitious way to confirm paternity
B) he is advancing in age and may have developed a new mutation
C) screening of all couples is standard-of-care nationally
D) advances in knowledge about the CF gene has identified more testable mutations
E) gene therapy for correction of the carrier state has become available
37. The ultimate goal of the Human Genome Project is to:
A) clone people
B) provide information for prenatal manipulation of genes and tailoring of offspring
C) characterize all proteins in the human body down to the quantum level
D) sequence all the DNA in the human nuclear and mitochondrial DNA
E) develop germ-line gene therapy for the twenty major genetic diseases
38. By five (5) years of age, how many children may be recognized to have a congenital anomaly?
A) 0.5-2%
B) 5-7%
C) 10-15%
D) 25-30%
E) 55-60%
39. You have been called to the hospital newborn nursery to see a baby with Down syndrome.
The diagnosis is clinically apparent, and you leave the nursery to go talk to the parents
about the diagnosis. On the way to the mother's room, you decide that there is a specific,
relatively small, amount of genetic information that you absolutely must give them right
now. In your head, you run through various ways of cushioning what you must tell them.
The purpose of `cushioning' genetic information about a child's disease when we give it to
families is to:
A) influence their course of action to what is most medically appropriate
B) delay parental shock until the information is completely told
C) assuage parental guilt, then you can tell them the important stuff at a later meeting
D) tell the most important information in such a way that it can be understood as fully as
possible
E) stall for time until the primary care physician has a chance to tell them all the bad news
40. A gene is said to show pseudoautosomal inheritance if:
A) there is one copy on a sex chromosome and another on an autosome
B) there are homologous copies within the distal regions of Xp and Yp
C) it is a gene for a mitochondrial protein, but is found on the nuclear genome
D) the true gene is on an autosome, and there is a pseudogene on a the Xchromosome
E) it is transmitted from fathers to daughters, but not fathers to sons
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41. An. X-linked dominant allele causes hypophosphatemia in humans. A man with
hypophosphatemia marries a normal woman. What proportion of their sons will have
hypophosphatemia?
A) 0%
B) 25%
C) 50%
D) 75%
E) 100%
42. A woman had 2 brothers who died from Duchenne muscular dystrophy several years ago.
Her children include a daughter and 8 sons, all of whom have been examined and found not
to have the condition. What is the most likely chance that her daughter will have a son with
Duchenne muscular dystrophy?
A) Impossible to tell since it is not known whether or not she is a carrier
B) 1 in 4, because she is an obligate carrier
C) 1 in 8, because she has a 50% chance of being a carrier
D) Unlikely, because the actual chance that the woman is a carrier is lower than the
theoretical one, considering that she had 8 unaffected sons
E) Likely, because the unusual predominance of males in her offspring suggests that she
has a defective X chromosome
43. Fanconi anemia is a heritable chromosome instability syndrome. Patients have hematologic
abnormalities and/or malformations consisting of radial ray defects (anomalies of the
forearm and hand), short stature, and hypogonadism. The definitive test for Fanconi
anemia is:
A.
bone marrow biopsy
B.
bilateral forearm and hand x-ray
C.
series of complete blood counts
D.
chromosome breakage study
E.
gonadotropin stimulation test
44. Hereditary multiple exostosis (HME) is an autosomal dominant disorder characterized by
bony outgrowths from the ends of all of the long bones, normal face and no mental
retardation. The Langer-Gideon syndrome (LGS) is an autosomal dominant disorder
characterized by exostoses, short stature, sparse hair, bulbous nose and mental retardation.
The trichorhinophalangeal syndrome (TRP) is an autosomal dominant disorder
characterized by short stature, sparse hair, bulbous nose, normal intelligence and no
exostoses. Chromosome 8 deletions have been identified in some patients with LGS and
TRP. These conditions are related to one another by:
A) being genocopies of each other
B) being phenocopies of each other
C) being overlapping contiguous gene syndromes
D) demonstrating genetic heterogeneity
E) reciprocal imprinting
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Questions 45-48
A sex-linked recessive allele c produced a red-green colorblindness in humans. A normal woman
whose father was colorblind marries a colorblind man.
45. What are the chances that the first child from this marriage will be a colorblind boy?
A) 0%
B) 25%
C) 50%
D) 75%
E) 100%
46. Of the girls produced by these parents, what proportion can be expected to be colorblind?
A) 0%
B) 25%
C) 50%
D) 75%
E) 100%
47. Of all the children (sex unspecified) of these parents, what proportion can be expected to
have normal color vision?
A) 0%
B) 25%
C) 50%
D) 75%
E) 100%
48. A condition known as ichthyosis hystrix gravior appeared in a boy in the early eighteenth
century. His skin became very thick and formed loose spines that were sloughed off at
intervals. When he grew up, this "porcupine man" married and had six sons, all of whom
had this condition, and several daughters, all of whom were normal. For four generations,
this condition was passed from father to son. From this evidence, you surmise that the
gene is most likely located on:
A) Chromosome 2
B) The X Chromosome
C) The Mitochondria) Chromosome
D) Chromosome 15
E) The Y Chromosome
49. A patient with sickle cell trait is 18 weeks pregnant; the genotype of the father, who is
black, is unknown. The most efficient method for determining the genotype of the fetus is:
A) DNA analysis of fetal cells for sickle cell mutation
B) Hemoglobin electrophoresis of fetal blood
C) Linkage analysis of fetal DNA
D) Polymerase chain reaction assays of fetal cells from the maternal circulation
E) Ultrasonography of fetal spleen size.
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50. Anomalies that result from intrinsic abnormalities include:
A) Deformations and Disruptions
B) Disruptions and Malformations
C) Malformations and Dysplasias
D) Dysplasias and Disruptions
E) Deformations and Malformations
51. If a man of blood group AB marries a woman of blood group A whose father was of blood
group O, to what different blood groups can this man and woman expect their children to
belong?
A) B and O only
B) AB and A only
C) A, AB, and B
D) A and O only
E) A, B, and O.
52. A couple brings their child to see you because she has been born with a cleft lip. The father
tells you that he and one of his seven siblings also were born with a cleft lip. Your exam
fails to reveal lip pits or other indications of a syndrome, so you conclude that this family is
affected by isolated cleft lip inherited in a multifactorial fashion. You tell them that their
risk to have another child with the same or a similar condition is significantly higher than
the general population because:
A) once a parent and child are both affected, it turns into a dominantly transmissible trait
B) they are not related in any way other than by marriage
C) it is a defect of low severity, and as such is associated with higher recurrence risks
D) the mother's next pregnancy will take place during an eclipse
E) the recurrence risk increases as more family members are affected
Questions 53 and 54:
A 22 year old woman and a 24 year old man meet while attending college and decide to marry.
He is a United States citizen of Ashkenazi Jewish extraction while she is an Irish national. The
young man has never been tested for Tay Sachs carrier status but knows that the disease incidence
in his ethnic group is I in 3,600 births. The young woman doesn't know her carrier status either,
but found out from a Irish geneticist that the disease incidence in the Irish population is I in
360,000.
53. Given this information, calculate the risk for this couple to have a child with Tay Sachs disease.
A) 1 in 3,600
B) 1 in 7,200
C) 1 in 36,000
D) 1 in 72,000
E) 1 in 360,000
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54. The couple from the above question has a child who is healthy. They are thinking about
having another child and are again worrying about the risk of Tay Sachs disease. The
father decides to be tested and is determined to be a carrier. Given this new information,
calculate the risk that they will have a child with Tay Sachs disease.
A) 1 in 1,200
B) 1 in 2,400
C) 1 in 3,600
D) 1 in 4,800
E) 1 in 12,000
55. In many places, the newborn screening tests include a screen for hemoglobinopathies. These tests
were added because:
A) infants with beta-thalassernia are now treated prophylactically with hydroxyurea
B) infants with beta-thalassemia are now treated prophylactically with penicillin
C) infants with sickle cell anemia need to be identified for bone marrow transplant
D) infants with sickle cell anemia are now treated prophylactically with hydroxyurea
E) infants with sickle cell anemia are now treated prophylactically with penicillin
Questions 56-65
Mr. and Mrs. Jones-Smith come to your office in their 8th week of pregnancy. They have one 7
year old son with the urea cycle defect of Ornithine Transcarbamylase (OTC) deficiency. He is
neurologically devastated from the disease. They are interested in having the current pregnancy
tested. They know that OTC deficiency is X-linked and know that it only affects males. Using
that logic, they ask about testing the gender of the pregnancy.
56. At this stage of the pregnancy, you tell them that the test for gender identification that can
be done to give them the earliest and most specific answer is:
A) Targeted ultrasound looking at the genitalia
B) Early amniocentesis for karyotyping
C) Fetal blood sampling for karyotyping
D) Chorionic villus sampling for karyotyping
E) Routine amniocentesis for karyotyping
57. In the time since the birth of their now 7-year old affected son, new technologies have
become available that allow for direct enzyme testing of a fetus. Specifically, it is possible
to test the activity of the OTC enzyme in fetal cells and determine whether a fetus is
affected. From the point of view of patient and pregnancy management the greatest
advantage to this new test is:
A) differentiation between normal and affected male fetuses
B) increased detection of carrier female fetuses
C) facilitated identification of carrier mothers
D) ability to monitor the effect of the maternal diet on the fetus
E) ability to monitor developmental activation of the enzyme
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58. As the couple ponders what you have told them, you wonder whether Mrs. Jones-Smith knows her
carrier status. Based on the reasoning of Haldane's Theorem, youknow that her baseline risk of being a
carrier for OTC deficiency is:
A) ~0
B) 1/4
C) 1/3
D) 2/3
E) ~1
59. If Mrs. Jones- Smith is not a carrier, the chance that this pregnancy will result in an
affected male is:
A) ~0
B) 1/4
C) 1/3
D) 2/3
E) ~1
Questions 60-66 (continued)
60. You ask the Jones-Smiths if you can have a little more information about their families.
They tell you that they each have two siblings. Both of Mrs. Jones-Smith's siblings have
healthy children, while Mr. Jones-Smith has only one nephew. Mrs. Jones-Smith's
mother died last year in a motor vehicle accident and both of Mr. Jones-Smith's parents are
still living and are healthy. No one in the family is on an unusual diet and no one is
mentally retarded. As far as the couple knows, they are not blood relatives. The other
most significant question that you have to ask is:
A) whether anyone has had any miscarriages or stillbirths
B) whether Mrs. Jones-Smith might have been exposed to anything during her previous
pregnancy
C) who the affected child looks like in the family
D) what the ethnic/nationality background of the family is
E) whether there have been any children who died as infants
61. You find out that Mrs. Jones-Smith had a brother who died at a few days of age,
reportedly because or an infection. Knowing that the manifestations of OTC deficiency in
infants overlap significantly with those of infection, you are suspicious that that child
actually died of the genetic disease. Your concerns that Mrs. Jones-Smith is a carrier:
A) do not change significantly
B) increase
C) decrease slightly
D) are not affected by the new data
E) decrease significantly
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62. The Jones-Smith's tell you that they are, indeed, interested in more precise and specific
testing if it is available. You do not know yet which test may be most appropriate for
them, as you do not know what they plan to do with the information. It is important to ask
what their plans may be because:
A) you want to be able to persuade them to terminate because this is a devastating disease
B) they may not know all of the options available to them
C) you prefer to order the most expensive test that their insurance will cover
D)you want to confirm that they will do what you would do in this situation
E)-you do not want them to be saddled with another affected child
63. The couple tells you that they are not interested in terminating a pregnancy, but also do not
wish to have another child who is neurologically devastated. Your recommendation to
them is:
A) they meet with some other families to get another perspective
B) that they reconsider termination as the only logical option
C) that they do not need prenatal testing if they are not going to choose to terminate
D) not to tell anyone, and let the baby die at home if it gets sick in the first few days
E) to deliver at a hospital that is equipped to handle an affected baby if necessary
Questions 64-66 (continued)
64. After the appropriate testing, you contact the couple to tell them that the current fetus is indeed, an
affected male. Plans are made to handle the delivery of the baby and his immediate post-partum care. The
most important thing about immediate care of the baby is to:
A) avoid contact with the other family members
B) feed the baby large amounts of specific amino acids
C) isolate him from the rest of the nursery
D) restrict his diet so that he receives a small, controlled amount of protein
E) remember not to give him the diphtheria vaccine
65. 11 months after birth, the boy, now named William, is healthy, active, and normal in
3 development. He has been carefully monitored and treated by his geneticists and his
parents have been fastidious in management of his OTC deficiency. The parents now are
seeking a more permanent `cure' for William's disease. You tell them that the only
currently available, long term `cure' is:
A) liver transplant
B) keep him on his special diet
C) retroviral gene therapy
D) bone marrow transplant
E) weekly infusion of normal gene product
66. It is late in the evening. You are called to see a fetus that has just miscarried at 15 weeks
gestation. The mother is not known to the hospital and presented, in labor and delivering,
to the emergency room about 45 minutes ago. You examine the fetus and find that it has
features consistent with a diagnosis of Turner syndrome (45,X karyotype), and you collect
tissue for a karyotype to confirm this. The mother is still in the delivery room, and is
awake, but sedated. The family is available in the waiting room. Your best course of
action is to:
A) go tell the family everything and make an appointment to talk to the mother in 3 weeks
after the chromosome report is back
B) go tell the mother everything and make an appointment to talk to her again in 3 weeks
- 14 -
after the chromosome report is back
C) write a detailed note in the chart and defer talking to anyone until the chromosome report
is back
D) go introduce yourself to the mother, answer any immediate questions, and tell her that
you will talk to her more in the morning
E) write a detailed note in the chart, leave literature for the mother based on your clinical
diagnosis, and go tell the family everything.
67. Consent is required in order to enroll people in screening programs of almost any type.
The one exception to this rule is newborn screening. All newborns in the United States or
babies born to US Military Personnel overseas are subject to screening for phenylketonuria
and other genetic diseases. Consent of the parents is not required for this screening to be
done. This exception exists because:
A) the public health issue of avoiding the consequences of these diseases takes precedence
over family autonomy.
B) testing on children does not generally require the consent of parents
C) consent is not required for any genetic screening as long as the results are kept
confidential
D) the lobby for providers of special infant formulas is so strong that congress will not
address the issue
E) the courts have mandated that this is an appropriate hospital policy in the face of early
discharges of newborns and their mothers
68. The Hardy-Weinberg Equilibrium Theory states that genotypes are distributed in proportion
to the frequencies of individual alleles in a population and remain constant from generation
to generation. It explains the basis for the constant gene frequencies seen in the population.
One supposition of the theory is that:
A) with entirely random mating, many generations are required to reach equilibrium
B) a high proportion of consanguineous matings will cause deviation from equilibrium
C) a dominant allele will ultimately replace its recessive counterpart over time
D) allele frequency will be unaffected by behavior patterns
E) allele frequency will be affected by natural disasters
69. Assume mutation analysis detects 90% of CF chromosomes. A consultant has a sibling
with CF who has one copy of the QF508 mutation and one unidentified mutation. The consultant
has neurative mutation studies. The probability that the consultant is a carrier is
A) 2/3
B) 1/2
C) 1 /3
D) 1/6
E) 1/15
70. The risk for subsequent affected children to a couple with a child with a multifactorial trait
club foot:
A) Is 1/4
B) Does not depend on parental phenotypes
C) Is significantly higher for males, as in all multifactorial traits
D) Depends upon whether there are any affected first or second degree relatives
E) Does not increase with the birth of every affected child
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71. The Chorionic Villus Sampling procedure was introduced in 1968, and can be performed
either transabdominally or transcervically. It has a number of diagnostic advantages over
amniocentesis. One drawback to CVS relative to amniocentesis is that:
A) CVS must be done at an earlier gestational age
B) CVS require more time to generate preliminary cytogenetic results
C) it is not possible to evaluate the risk of neural tube defect
D) even if an abnormality is found, pregnancy termination must be delayed
E) it requires elaborate and specific instrumentation
72. Duchenne and Becker muscular dystrophies both result from mutations in the gene for
dystrophin. The diseases differ in onset and severity, but not in inheritance pattern. They
should therefore be considered:
A) pleiotropic disorders
B) allelic disorders
C) variably penetrant disorders
D) closely linked disorders
E) reciprocally expressed disorders
73. The father of a 24 year old male consultand has a diagnosis of Huntington disease and is
cared for at home. Several paternal relatives are similarly affected, and most are now in
long-term care facilities. The consultand and his wife request predictive testing. All
appropriate blood samples are obtained in duplicate, and the results indicate that there is
nonpaternity; that is, the consultand's biological father is not the legal and affected father
and the consultand has not inherited the Huntington gene. The mother is interviewed
separately and gently but does not confirm your genetic interpretation. Which one of the
following solutions would best aid the consultand and his wife in planning their future?
A).Respect the autonomy of the mother and tell the patient the molecular resting was not
informative
B). Impress upon the mother the importance of divulging the results to her son
C) Respect the autonomy of the mother, say nothing about the nonpaternity, but tell the
patient that the results indicated that he has not inherited the Huntington gene
D) Call the couple in and review all the results, including the nonpaternity
E) Obtain a court order releasing you from confidentiality to the mother so that you can
reveal all of the results, including the nonpaternity, to the consultand
74. A child is ready to go home from the hospital with her mother. She was born 48 hours
previously and has been well. The family is of Ashkenazic Jewish descent. Before being
discharged, the mother is informed that the child must undergo a screening test for genetic
disorders. The mother would rather not have the testing, but you tell her that it must be
done because:
A) it is mandated by hospital policy
B) it is mandated by state law
C) it is mandated by federal law
D) the baby is of a high risk ethnic group
E) the baby is of a high risk gender
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75. The results of a recent study reported a DNA polymorphism linked to a debilitating
dominant disease with an adult age of onset. The data revealed a LOD (log of the odds)
score = 9.0 at θ = 0.01. What conclusion would you draw?
A) The DNA marker may be a good presymptomatic or prenatal diagnostic tool
B) The study was uninformative
C) Families with the disease need not be made aware of the study
D) The LOD score was too low to be significant
E) The recombination fraction (e) is too low to support linkage
MULTIPLE MATCHING
Each group of items in this section consists of lettered options followed by a set of numbered
items. For each item, select the one lettered option that is most closely associated with it. Each
lettered option may be selected once, more than once, or not at all.
Questions 76-79
A) Malformation
B) Disruption
C) Deformation
D) Dysplasia
For each clinical situation described below, select the corresponding type of congenital anomaly.
76. A child has short leas because of abnormal formation of cartilage (as reflected by histologically
abnormal growth plates) in the long bones
77. A child is born with only her right kidney because of complete loss of blood supply to the left
kidney at 14 weeks of gestation
78. A twin has an indentation in his skull because his head and his twin's head were both tightly
jammed into the mother's pelvis during the last month of pregnancy
79. A child is born with severe chorioretinitis and blindness of her right eye because of an in utero
rubella infection
Questions 80-94
A) Online Mendelian Inheritance in Man (OMIM)
B) Genome Data Base (GDB)
C) POSSUM
Match the statement below with the genetic database that it best describes
80. Provides lists of genetic polymorphisms
81. Allows searching on keywords with weighted importance
82. Continuously updated clinical information
83. Gives information about detection methods for genetic markers
- 17 -
For each item, select the one lettered option that is most closely associated with it. Each lettered option
may be selected once, more than once, or not at all.
Questions 84-88
A) Dietary Treatment
B) Vitamin Treatment
C) Specific Drug treatment (not vitamins)
D) Replacement of Gene Product
Match the disease below with the most common treatment modality
84. Phenylketonuria
85. Gout (Parial HPRT deficiency)
86. Hemophilia
87. Thalassemia
88. Wilson Disease
For the purposes of evaluating and refining/modifying the course, we would appreciate an answer to the
following question.
1) Which problem did you work on in your Small Group Session?
A) Problem 1 - Huntington Disease
B) Problem 2 - Spina Bifida
C) Problem 3 - Tay Sachs
D) Problem 4 - Chromosomal Anomaly
E) Problem5-NF,SS
- 18 -
ANSWERS:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
39.
40.
41.
42.
43.
44.
C
E
D
C
D
B
A
D
B
E
A
D
A
B
A
D
C
D
E
C
C
E
B
C
B
A
A
D
A
A
C
B
D
A
C
D
D
B
D
B
A
D
D
C
45.
46.
47.
48.
49.
50.
51.
52.
53.
54.
55.
56.
57.
58.
59.
60.
61.
62.
63.
64.
65.
66.
67.
68.
69.
70.
71.
72.
73.
74.
75.
76.
77.
78.
79.
80.
81.
82.
83.
84.
85.
86.
87.
88.
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B
C
C
E
A
C
C
E
C
A
E
D
A
D
A
E
B
B
E
D
A
D
A
B
B
D
C
B
C
B
A
D
B
C
B
C
B
A
B
A
C
D
D
C