Genetic Block 4

Question 1

In retinoblastoma, RB1 gene protein product regulates the cell cycle to cause cells to divide in a controlled manner. Once both copies of the tumor suppressor are mutated in a cell, cell cycle control is lost, and the cell can divide uncontrollably, leading to tumor formation. Two hit hypothesis of genes is associated with which other type of cancer/s?

a. familial breast cancer
b. familial colon cancer
c. familial melanoma
d. neurofibromatosis
e. all the above

Answer 1

all the above

Question 2

Earlier, the procedure used in diagnosis of genetics was to arrest mitosis in dividing cells in metaphase; hence, cells which are capable of growth and division were used for this purpose. Now, with recent advances somatic cells and cells in dried blood can also be used. Which cells, however, can never be used for DNA analysis?

a. Mature RBCs
b. Immature RBCs
c. Epithelial cells
d. Seminal fluid
e. Dead WBCs

Answer 2

Immature RBCs

Question 3

In certain genetic diseases, it is necessary to directly remove the compound causing harm to the body. Which of the following procedure/s is/are used to carry out this mechanism?

a. LDL apheresis
b. Plasmapheresis
c. Dialysis
d. Immunepheresis
e. All the above

Answer 3

LDL apheresis

Question 4

In gene therapy, correct copies of genes need to be transmitted to the dividing or non- dividing cells. Which of the following is the non-viral vector used for this purpose?

a. HTLV
b. Adeno-associated viruses
c. HIV
d. Blood
e. Liposome-polycation complexes

Answer 4

Adeno-associated virus

Question 5

A 21 year old woman presents to you for counseling. She is 8 weeks pregnant for the first time. She gives you history that her brother has a genetic condition because of which he is suffering from mental retardation and characteristic features. What will you advise her regarding her present pregnancy?

a. Terminate pregnancy
b. Use contraception
c. Adopt children
d. Take a chance
e. Do prenatal diagnosis

Answer 5

Do prenatal diagnosis

Question 6

In Duchene muscular dystrophy, the protein at fault is the ‘Dystrophin’ protein. The process of identifying a specific protein fragment, for better understanding of its structure, is known as_______?

a. Southern blot
b. Northern blot
c. Western blot
d. Eastern blot
e. Simple biochemical analysis

Answer 6

Western blot

Question 7

Gene therapy is introduction of the correct copy of gene into cells that have been cultured from the patient. Which is/are the target cell/s used?

a. Branch cells
b. Genital cells
c. Stem cells
d. Epithelial cells
e. All the above

Answer 7

Stem cells

Question 8

For achieving best corrective results for genetic diseases, gene therapy is used. This can be successful only if we can achieve ideal conditions for ideal vector for gene transfer. Which of the following conditions is ideal?

a. Ability to transduce only dividing cells but not the non-dividing cells
b. Ability to integrate into any location in the host cell but not the DNA
c. Unstable episome can be used.
d. Ability to target the desired type of cell.
e. Inconvenient to use will also do

Answer 8

Ability to target the desired type of cell

Question 9

Who amongst the following requires an immediate genetic counseling?

a. Mother of a 12 year old Down syndrome child
b. Couple who are married in a consanguineous setting
c. Newly diagnosed abnormality in a patient
d. Pregnant woman with advanced maternal age
e. Occupational exposure to radiation

Answer 9

Couple who are married in a consanguineous setting

Question 10

A middle aged man has history of enlarged spleen causing pain on the left side, malaise, joint and/or hip pain, low-grade fever, increased susceptibility to infections, anemia, and thrombocytopenia with easy bruising. He has an elevated white blood cell count on a routine laboratory tests [WBC = 250,000 mcL (normal= 4000-10,000 mcL)]. What is the chromosomal translocation associated with CML (chronic myelogenous leukaemia)?

a. ABL-BCR
b. Philadelphia chromosome
c. 9: 22
d. All the above
e. None of the above

Answer 10

All the above

Question 11

During your internal medicine rotation you are placed under the genetic counselor. Following are the steps involved in genetic counseling?
1. Based on intellectual capacity of the patient, inform the patient or relative responsible for the patient
2. Risk assessment
3. Diagnosis based on detailed investigations
4. Maintain contact information and detailed records for future communication
5. Inform all the options available
Mention the correct sequence in which genetic counseling should take place.
a. 1-2-3-4-5
b. 3-2-1-5-4
c. 3-2-1-4-5
d. 2-3-1-5-4
e. 5-4-3-2-1

Answer 11

3-2-1-5-4

Question 12

A patient presents to you with different colors of iris, one blue and the other green. This is an example of somatic mosaicism. A small possibility of diagnostic error because of placental mosaicism is seen with which invasive prenatal diagnostic test?

a. Amniocentesis
b. Fetoscopy
c. Ultrasonography
d. Biochemical analysis
e. Chorionic villus biopsy

Answer 12

Chorionic villus biopsy

Question 13

In cancer, oncogenes are activated whereas tumor suppressor genes are inactivated. What are the mechanisms by which oncogenes are activated?

a. Point mutation
b. DNA amplification
c. Chromosomal rearrangement
d. Telomerase activation
e. All the above

Answer 13

All the above

Question 14

An 18 year old male is brought in to the ER with complaints of wheezing, shortness of breath. He has history of progressive shortness of breath since 2-3 yrs. He has never smoked tobacco nor is he asthmatic since childhood. After initial management he stabilizes. On radiological examination as in fig.1, shows severely emphysematous lung fields and a large bulla. Family history is positive for emphysema in cousins and uncles at young age. Based on clinical, biochemical and genetic analysis you come to the conclusion that he has Alpha 1 antitrypsin deficiency. What is the best treatment option for the disease in this person

a. Stop smoking
b. Lung transplant
c. Replacement of alpha 1 antitrypsin
d. Bronchodilator medicine
e. Steroids

Answer 14

Replacement of alpha 1 antitrypsin

Question 15

A cord blood bank is a facility which stores Umbilical cord blood for future use. Both private and public cord blood banks have developed since the mid-to-late 1990s, in response to the potential for cord blood in treating diseases of the blood and immune systems. Which of the following is the advantage of using placental/cord blood over bone marrow transplantation?

a. Extreme histoincompatiblility of the placental blood than of other allogeneic donor cells.
b. Engraftment does not occur if there is even one HLA antigen mismatch between the donor and the recipient.
c. The wide availability of placental blood, together with the increased tolerance of histoincompatible donor cells, greatly expands the number of potential donors for any recipient.
d. The risk of graft-versus-host disease is substantially increased.
e. All of the above

Answer 15

The wide availability of placental blood, together with the increased tolerance of histoincompatible donor cells, greatly expands the number of potential donors for any recipient

Question 16

Pre natal diagnosis is an important step in genetic disease diagnosis, where decision can be taken between continuation and termination of pregnancy. Which of the following is an invasive test done specifically between 10-12 weeks (max 14 weeks)of gestation?

a. Amniocentesis
b. Fetoscopy
c. Ultrasonography
d. Biochemical analysis
e. Chorionic villus biopsy

Answer 16

Chorionic villus biopsy

Question 17

What is the process that involves increasing the expression of a normal gene that compensates for the effect of mutation?

a. Modification of entire somatic genotype
b. Modulation of gene expression
c. Gene repair
d. Enhancement of residual protein function
e. RNA interference to degrade mutant mRNA

Answer 17

Modulation of gene expression

Question 18

Which of the following is the enhanced use of alternative metabolic pathways to reduce the concentration of a harmful metabolite?

a. Diversion
b. Depletion
c. Inhibition
d. Replacement
e. LDL apheresis

Answer 18

Diversion

Question 19

Cancer occurs because of certain genetic mutations resulting into changes in the cellular processes. Which of the following are the changes seen in the cell physiology that sustains a cancer which is malignant?

a. Insufficient growth signals.
b. Sensitive to growth-inhibitory signals.
c. Evading programmed cell death.
d. Limited replication potential.
e. Noninvasiveness

Answer 19

Evading programmed cell death

Question 20

Erb B2/ Her2 is a gene associate with which type of cancer?

a. Colon
b. Ovary
c. Endocrine
d. Breast
e. Skin

Answer 20

Breast

Question 21

Certain DNA molecules can exist separately from the bacterial or yeast chromosome and replicate independently from the microorganisms own chromosomes. Amongst these some have no specific shape. Some of such DNA molecules that are specifically circular and double stranded is/are called as ______?

a. Vector
b. Plasmid
c. Naked free ended DNA
d. All the above
e. None of the above

Answer 21

b. Plasmid

Question 22

56 year old male presents to you with history of alternating constipation and diarrhea and weight loss. CT scan, colonoscopy and histopathology report is suggestive of Colon cancer. Which of the following is the reason why any cancer can develop?

a. Mutagenic Damage to DNA via Ionizing Radiation
b. Random replication errors
c. Inheritance of Cancer-Risk Genes
d. Mutagenic Damage via Chemical Changes
e. All the above

Answer 22

All the above

Question 23

A 20 year old male patient, diagnosed as hemophilia in his childhood, on regular treatment, follows up in your clinic with his wife who is 18 years old. They are planning pregnancy and they are now seeking genetic advice. What will you inform them at this point?

a. Whether boy or a girl, your children will never inherit the disease.
b. Your wife is too young to get pregnant.
c. You have a serious genetic condition and you will not be able to reproduce.
d. Check if wife is X-lined recessive to hemophilia before giving them risk assessment.
e. Whether boy or a girl, all your children will suffer from the disease.

Answer 23

Check if wife is X-lined recessive to hemophilia before giving them risk assessment

Question 24

A patient with glioblastoma recurrence is been treated in your hospital. He said he has been injected with a CD enzyme gene that will activate the drug Flucytosine that he is currently on and that the side effects of this particular medicine is very less. What do you think is the therapy that has been FDA approved, is been tried on him?

a. Tumor suppressor gene therapy
b. radiation therapy
c. immunotherapy
d. suicide gene therapy
e. all the above

Answer 24

Immunotherapy

Question 25

A 39 year old Asian woman presents to the clinic with her 6 month old baby for the first time. On history, you find out that this is her first child, born after 12 years of marriage and after 3 miscarriages. She had not received any prenatal assessment or medical care. The patient informs you that the baby is very precious to her and her family. There is no family history of any significant genetic disorders. Presently she has no complaints. You give one (fig.2) look at the baby and you know there is something wrong. What is the first step that you will do in this case?

a. Counsel the mother regarding Down syndrome that the baby has.
b. Tell the mother she has chances of conceiving a baby with Down syndrome in future
c. Do karyotyping of the baby’s cells to detect the genetic condition
d. Take the mother’s contact details and tell her to be in touch
e. Tell the mother to follow up on a later date while you take time to read more about the baby’s features

Answer 25

Do karyotyping of the baby’s cells to detect the genetic condition

Question 26

Consider the following statements regarding PCR

i. First step involved in PCR is Annealing
ii. Automated thermal cyclers are used in this techniques
iii. Process of binding of primer to denatured strand is called elongation
iv. Amplified segment can then be tested by AS0 hybridization methods to detect a mutation

Which of the above statements are true/false

a. i=true, ii=true, iii=true, iv=true
b. i=false, ii=false, iii=false, iv=false
c. i=true, ii=false, iii=true, iv=false
d. i=false, ii=true, iii=false, iv=true
e. i=true, ii=true, iii=false, iv=false

Answer 26

i=false, ii=true, iii=false, iv=true

Question 27

A 38 yr old male presents to your clinic with complaints of Loss of weight and Loss of appetite with multiple skin lesions as shown in the fig.5. He is a known case of hemophilia and has received multiple blood transfusions in the past. On further testing of his skin lesions it was found that he has now developed Kaposi Sarcoma a cancer of lymphatic endothelium. Which of the following viruses might the patient be infected with that has given aid in development of this cancer?

a. HIV
b. HPV
c. Hepatitis B
d. EBV
e. Chicken pox virus

Answer 27

HIV

Question 28

30. While on your ER rotation, a 22 yr old patient is rolled in unconscious at 3pm in the afternoon. He collapsed on his way back home from work. His friend gave a history that he was feeling uneasy all day at work and was seen sweating, clutching his chest before he collapsed. On arrival you and your team did best to resuscitate him, however he could not be revived and was eventually declared dead. On further enquiry it was found that he had family history of cardiovascular disease .The post mortem report confirmed death due to massive myocardial infarction. The blood report suggested total cholesterol levels of 950 mg/dL (normal

Answer 28

1,5