BIO 836: Pathophysiology
DISCUSSION 1: JUSTIN
DIRECTIONS: After reading Chapters 8, 9 of the required text and listening to the related
audio lectures, you should be able to answer the questions concerning the case described below.
Contact your group members in the discussion forum corresponding to your Group number and
formulate your answers to the questions.
Discussion with your group members is required between September 16-19, 2015.
One group member should post the group’s summary (“ideal answer”) by midnight,
Saturday (September 27th)
You will be graded on your group submission (45 points) and your participation
within the group (5 points), so make sure you all agree with the answers and
REQUIREMENTS FOR SUMMARY POST OF THE “IDEAL ANSWER”:
The result of your group discussion is to develop an “ideal answer” to the case questions.
Discuss your individual rationale/answers and come to a consensus as to which is the
correct statement for each question with rationale.
When you comment on a classmate’s thoughts, be diplomatic, but make sure you analyze
their answers. In other words, don’t type “Good thinking! That is exactly what I thought!”
That kind of comment will not be given any points, because it doesn’t promote in-depth
thinking on the case.
Also agree on the rationale for why the other statements are incorrect.
o i.e. For each statement (A-E), you must state if it is correct or incorrect and WHY
you think it is correct or incorrect!
o Therefore, your response to each statement
“A (or B-E) is correct (or incorrect) because…
o Make sure to answer each question directly and explain your reasoning
thoroughly. However, answers to each question should need no more than a few
o Write in complete sentences without any abbreviations! The group will lose 1
point for each abbreviation, misspelled word or incomplete sentence!!!
One member of the group should post the group’s summary statement in the discussion
forum by the due date.
o For this final post enter the subject heading “GROUP # – Final Case Solution”
[substitute your group number]
o Include all participating group members’ names in the summary post.
o Your answers must be labeled in the same order as the questions listed below
and must be identified by the question number.
BIO 836: Pathophysiology
DISCUSSION 1: JUSTIN
Justin was born after an uneventful pregnancy and weighed 3.1kg. At 3 months, he
developed otitis media and an upper respiratory tract infection. At the ages of 5 months and 11
months, he was admitted to hospital with Haemophilus influenzae pneumonia. The infections
responded promptly to the appropriate antibiotics on each occasion. At the age of 16 months old,
he developed balanitis. He is the fourth child of unrelated parents: his three sisters show no
predisposition to infection.
Examination at the age of 18 months showed a pale, thin child whose height and weight
were below the third percentile. There were no other abnormal features. He had been fully
immunized as an infant (at 2, 3 and 4 months) with tetanus and diphtheria toxoids, whole-cell
pertussis, Haemophilus conjugate vaccine and oral polio. In addition he had received measles,
mumps and rubella vaccine at 12 months. All immunizations were uneventful.
Immunological investigations into the cause of his recurrent infections showed severe
panhypogammaglobulinemia with absent antibody production. Although there was no family
history of hypogammaglobulinemia, the absence of mature B-lymphocytes in his peripheral
blood strongly supported a diagnosis of infantile X-linked agammaglobulinemia (Bruton’s
disease). His antibody deficiency was treated by 2-weekly intravenous infusions of human
normal IgG in a dose of 400mg/kg body weight/month. Over the following 2 years, his health
steadily improved: his weight and height are now on the 10th percentile, and he has had only one
episode of otitis media in the last 18 months.
1. Which of the following statements is correct?
A. Justin’s immunodeficiency puts him at great risk for viral infections
B. Justin’s immunodeficiency puts him at great risk for fungal infections
C. Justin’s immunodeficiency puts him at great risk for bacterial infections
D. Justin’s immunodeficiency puts him at great risk for parasitic infections
E. Justin’s immunodeficiency puts him at great risk for seasonal allergies
2. Justin’s immunizations during in his first year of life will:
A. Provide with life-long immunity to infection with those microorganisms.
B. Not protect him from infection because he cannot produce specific antibodies
C. Induce long-lived innate immune or inflammatory responses
D. Induce adaptive responses to bacterial but not viral vaccines
E. Induce production of IgM but not IgG antibodies against the microorganisms
3. Which of the following statements about X-linked recessive statements is correct?
A. Fathers pass the trait to their sons but not their daughters
B. Mothers pass the trait to their daughters but not their sons.
C. Sons must receive two defective genes in order to express the disease
D. Daughters cannot pass the disease to their sons.
E. Mothers can pass the trait to both their sons and daughters