Page 1 of 1: Ethics important clinical cases/9MCQ

doctorkarim · Credits: 84453 My Scrapbook

Q-1 Confidentially in the physician-patient relationship should be broken in which of the following clinical scenarios?
A A young woman has just tested positive for HIV. She begs you not to tell the test result to her boyfriend of 4 years.
B Your 23 year-old patient is starting a new job and her employer requests the results of her genetic test for expansion of triplet repeats in the Huntington Disease gene.
C You see a patient in the Psychiatry outpatient clinic who tells you he has recurring thoughts of murdering his wife, and he is now devising a realistic plan to do so.
D All of the above
E A and C only
ANSWER ? I LEAVE THAT FOR DISCUSSION

Q2-A large percentage of individuals with a1-antitrypsin deficiency will develop chronic obstructive pulmonary disease (COPD) or emphysema. The severity of this disease will be significantly increased if the patient is:

A heterozygous for the mutation, with one normal copy of the a1-antitrypsin gene.
B a woman.
C homozygous for null alleles of the elastase gene.
D a cigarette smoker.
E neutropenic.
ANSWER ? WAIT REPLY for discussion
Q3-Which of the following clinical features are characteristic of familial cancer syndromes?
A Earlier mean age of cancer onset, compared to sporadic form of the same tumor type
B Two or more independent primary tumors in a single individual
C Observed tumor types are rarely seen as sporadic cancers
D all of the above
E none of the above
F A & B ANSWER ? wait reply from you for discussion

Q4-Assuming Hardy-Weinberg equilibrium for alleles at the CFTR (cystic fibrosis) locus in the U.S. Caucasian population, and given that the mutant allele frequency, q, is 1/50, what fraction of this population are carriers of a CFTR mutation?

A 1/50
B (49/50)2
C 1/100
D (1/50)2
E 2/50
AnswerE NOTE-answer of this question taken from refrence

The normal allele frequency is calculated using the formula p+q=1; so given the mutant allele frequency of q=1/50, p=49/50. For a population in Hardy-Weinberg equilibrium, the heterozygote carrier frequency is 2pq = 2 x 49/50 x 1/50 = [snip]/2500. The closest answer of those given is 2/50.
Q5-A 26-year-old woman of Norwegian descent seeks genetic counseling. Her brother died at age eight of documented cystic fibrosis. Both of their parents are deceased. The woman undergoes DNA testing for 70 CF mutations which collectively detects approximately 90% of CF carriers of northern European descent. Testing reveals that she is negative for all 70 mutations. What is the probability that she is a heterozygous carrier of CF?

A 2/3
B 1/6
C 1/15
D 1/25
E < 1%
ANSWER ? FOR DICUSSION reply to reach the correct answer please
Q6-Which of the following observations is the strongest evidence for an important genetic component in the causation of type-1 diabetes mellitus (IDDM)?

A Pancreatic b-cell autoantibodies are frequently present.
B Approximately 10% of affected indivifuals have an affected sibling.
C Onset of disease is usually in childhood.
D The concordance rate in monozygotic twins is approximately 30%.
E The concordance rate in monozygotic twins is five times that in dizygotic twins.
ANSWER? REPLY FOR DISCUSSION
Q7-A. Polymorphism
B. Allelic heterogeneity
C. Locus heterogeneity
D. Variable expressivity
E. Polygenic disease
1-About 10% of pheochromocytomas (a tumor of the adrenal medulla) occur in patients with familial cancer syndromes, one of which is multiple endocrine neoplasia syndrome, type II (MEN-II). In most MEN-II families, there are germline mutations in the RET gene, located on chromosome 10. Most commonly, these mutations are in one of several different codons encoding cysteines. This is an example of:
A B C D E
2-MEN-II is an autosomal dominant cancer syndrome. Another autosomal dominant cancer syndrome associated with pheochromocytomas (and occasionally misdiagnosed as MEN-II) is von Hippel-Lindau disease, the gene for which is on chromosome 3. With regard to familial pheochromocytomas, these two diseases are examples of:
A B C D E
3-95% of individuals affected with MEN-II have thyroid C-cell hyperplasia and medullary thyroid carcinoma, 50% have pheochromocytoma, and about 20% have hyperparathyroidism. This is an example of:
A B C D EANSWER 1- B
BAllelic heterogeneity refers to a variety of alleles of a single gene (locus) that can all cause the same or a similar phenotype. In this case, various alleles of the RET gene on chromosome 10 can all cause MEN-II.
Locus heterogeneity refers to a variety of different genes, any of which may be mutated to cause the same or a similar phenotype. Polymorphism refers to variant alleles that have appreciable frequencies in the population under study. There is insufficient information given to decide whether the RET gene is truly polymorphic. Polygenic disease and variable expressivity do not apply here.
ANSWER 2- C
C As discussed above, locus heterogeneity refers to the situation in which mutations at a variety of genetic loci can cause the same or a similar phenotype. In this example mutations on chromosome 10 and chromosome 3 can both cause similar autosomal dominant cancer syndromes that include pheochromocytomas.
Note that "polygenic disease" refers to diseases that are caused by the concerted effect of multiple genes, each of which has a relatively minor effect. Both genes in this example, however, are practically the only important genes in their respective cancer syndromes
ANSWER 3- DD Variable expressivity refers to variation in the nature and severity of a phenotype. This is a frequent characteristic of autosomal dominant diseases that can affect multiple organ systems. In this example, the nature of the MEN-II phenotype can vary: affected patients may have medullary thyroid carcinoma or pheochromocytoma or hyperparathyroidism.
Variable expressivity should not be confused with penetrance, which refers to the clinical expression, or lack of it, of a mutant gene. Thus penetrance is an all-or-none phenomenon .
Q8-Patients with hemoglobin SC disease:

A Frequently die in utero from complications of the hemoglobinopathy.
B Have a different mutation in each copy of their b-globin gene, though both are in the same codon.
C Could not have a child with sickle cell disease.
D Never experience sickle cell crises.
E Exhibit an excess of embryonic z-chains in their adult red blood cells.
ANSWER? B
Q9-Sickle cell anemia is:

A an X-linked recessive disease.
B caused by mutations in either the alpha-globin gene or the beta-globin gene.
C rarely due to the same mutation in unrelated individuals.
D always caused by the same point mutation in the beta-globin gene.
E an autosomal dominant disease.
ANSWER? FOR DISCUSSION DROP UR REPLY
ANSWER D

sd04 · Credits: 4337 My Scrapbook My Reading List 9 Books

hello
well ref to ur 1st quest--------aldo all physicians r expected to maintain pat confidentiality BUT not required to do so if the pat.is placing himself or others at serous risk n 2nd Huntington Disease gene i dont think so is reportable or keeping any1 at risk...so ans shud be A & C....
Further comments r welcome..

doctorkarim · Credits: 84453 My Scrapbook

hello
i got the answers for all 9 clinical cases ethics after searching
Q1-answer E
Genetic testing information should be kept in confidence and not disclosed to a third party such as an employer. The other two examples, though, are scenarios in which physician-patient confidentiality should be broken due to the realistic potential of harm to another person. The correct answer is A and C only.

Q2- Answer D

About 80% of individuals homozygous for the Z allele of the Pi (protease inhibitor) locus develop pulmonary emphysema. This observation lends support to the protease-antiprotease theory of emphysema, which holds that emphysema results from an imbalance between proteases like neutrophil elastase and protease inhibitors like 1-antitrypsin in the lung. The Pi locus codes for the 1-antitrypsin protein, which is produced predominantly in the liver and secreted into the serum. The Z allele results in defective transport of the 1-antitrypsin protein from the endoplasmic reticulum to the Golgi apparatus and consequent reduced serum concentrations. PiZZ homozygotes have serum 1-antitrypsin levels that are about 10% of normal.
Pulmonary emphysema in these patients occurs with greater severity and at an earlier age if the patient is a smoker. The protease-antiprotease theory of emphysema can explain the tendency of even normal smokers to develop emphysema, since cigarette smoke both increases the amount of protease in the lung and decreases the activity of alpha1-antitrypsin. In PiZZ individuals this effect is magnified.Having one normal copy of the alpha1-antitrypsin gene, having a deficiency of elastase, or being neutropenic would all be expected to reduce the severity of emphysema in PiZZ individuals.

Q3- answer F

As per lecture, the tumor types seen in familial cancer syndromes can also be seen in sporadic cases. This is one of the reasons that it can be difficult to look at a family history and know that there is an inherited syndrome present. The differences between an inherited case of cancer and a sporadic cancer include both two or more independent primary tumors and an earlier mean age of onset than in sporadic cases.

Q4- E

Q5 ANSWER B

Q6-E

Q7- ANSWER 1- B 2-C 3-D

Q8-B

Q9-D

sd04 · Credits: 4337 My Scrapbook My Reading List 9 Books

Thanku so much....

Pearl · Credits: 3484 My Scrapbook

thankyou, you 2 !!

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