Question 1

Which is the most common F-VIII mutation in patients with a severe phenotype (occurring in almost 50% of patients)?

Accepted Answer

A) Gross deletion of entire gene locus 
B) Point mutation involving the thrombin cleavage site 
C) Inversion mutation of intron 22 
D) Point mutation involving the site of VWF attachment

Question 2

Screening tests for the evaluation of VWD include the platelet count, APTT, PT, the bleeding time, and/or the PFA-100.Which of the following results would be evident in most cases of VWD?

Accepted Answer

A) Platelet count low 
B) Ristocetin platelet aggregation test decreased 
C) rRstocetin platelet aggregation test normal 
D) VWF: Ag assay normal

Question 3

A 5-year-old boy has his blood drawn for platelet aggregation studies.Ristocetin aggregation (RIPA) comes back abnormal with all other agonists displaying normal aggregation.VWF antigen is within normal limits.What is the most likely reason for this discrepancy?

Accepted Answer

A) The VWF antigen test was performed incorrectly, and should be repeated. 
B) The patient might be suffering from a qualitative platelet defect disorder. 
C) The RIPA exam was performed incorrectly, and should be repeated. 
D) Multimer analysis should be performed to confirm these findings.

Question 4

What type of VWD is the only type to have a decreased platelet count?

Accepted Answer

A) Type 1 
B) Type 3 
C) Type 2B 
D) Type 2N

Question 5

A known hemophiliac has developed an inhibitor.The physician in charge of his care wants to know how much inhibitor is present so that he can properly treat him.What two lab tests would he have to order to assess this?

Accepted Answer

A) APTT; factor assay 
B) Factor VIII: C level; Bethesda titer 
C) VWF antigen; Bethesda titer 
D) Type and screen; factor assay

Question 6

Use this case to answer the following questions: 
A 5-year-old boy visits his primary care physician after an accident on his bike.It was his first accident, and he fell on his knees.His mother noticed severe swelling in his knees and elbows, but thought that it was from the accident.She placed an ice pack on the affected areas and put him to rest.After a few days, the swelling had not improved, so she made an appointment to see his pediatrician.The physician asks him a few questions about the accident and then proceeds to perform a physical examination.The physician notes small hematomas on his elbows and knees and also on his upper torso.He draws blood, and the results are shown below. PT: 12.2 sec (RR: 11.3-12.8 sec)
INR: 1.12
APTT: 72 sec (RR: 23-32 sec)
Platelet aggregation studies: normal aggregation with all agonists
The physician admits him to the area hospital.
-What should be his next course of action in investigating these results?

Accepted Answer

A) He should repeat the aggregation studies. 
B) He should start the patient on Coumadin. 
C) He should order factor assays of the intrinsic pathway. 
D) He should order factor assays of the intrinsic, extrinsic, and common pathways.

Question 7

Which of the following clinical symptoms correlates with a severe form of hemophilia A or B?

Accepted Answer

A) Bleeding at circumcision with a factor level of 1-5 U/dL 
B) Excessive bleeding after surgery or trauma with factor levels of 6-30 U/dL 
C) Frequent spontaneous hemarthroses 
D) Infrequent spontaneous joint and tissue bleeds

Question 8

Which congenital deficiency(s) is suspected with a normal platelet count, an abnormal PT and APTT, and normal PFA-100 and thrombin time?

Accepted Answer

A) Factor VII 
B) Factors X, V, II (prothrombin) 
C) Factor VIII 
D) Fibrinogen

Question 9

What term describes hereditary or acquired disorders and relates to the absence of a coagulation protein, or to a protein that is present in the plasma but that is functionally defective?

Accepted Answer

A) Circulating anticoagulant 
B) Lupus anticoagulant 
C) Deficiency 
D) Dysfunctional

Question 10

Deficiency of coagulation proteins is defined as:

Accepted Answer

A) A decrease in the concentration of the coagulation proteins. 
B) A decrease in the concentration of the coagulation proteins and a subsequent decrease in the functionality of those proteins. 
C) A decrease in the concentration of the coagulation proteins or impaired functionality of those proteins. 
D) A decrease in platelets that causes a decreased functionality of the coagulation proteins.

Question 11

A preterm infant (29 weeks old) has a platelet count of 85 x 109/L.Is this a normal finding? Why or why not?

Accepted Answer

A) No, it is an abnormal finding, because infants have normal adult amounts of platelets after 27 weeks' gestation. 
B) Yes, this is a normal finding, because preterm infants have decreased platelet counts due to abnormal birthing circumstances. 
C) Yes, this is a normal finding, because platelet development is similar to lung development in an infant; levels are dependent upon the age of gestation. 
D) No, this is an abnormal finding, because preterm infants are subject to DIC, and that results in a decreased platelet count.

Question 12

How does von Willebrand's disease differ from Bernard-Soulier syndrome? Correlate the pathophysiology of both disorders in your response.Name at least two laboratory test methods by which to differentiate between the two.

Accepted Answer

The answer of How does von Willebrand's disease differ from...

Question 13

F-VIII deficiency and F-IX deficiency are classified as what category of disorders?

Accepted Answer

A) Autosomal dominant 
B) X-linked recessive disorders 
C) Autosomal recessive 
D) X-linked dominant

Question 14

What test(s) would help differentiate this disorder from other acquired disorders?

Accepted Answer

A) D-dimer 
B) Liver enzymes 
C) von Willebrand's factor 
D) All of the above

Question 15

Explain the inheritance pattern of the following disorders, and explain how this contributes to the clinical manifestations of the disorders:
a.Hemophilia A
b. Hemophilia B
c. von Willebrand’s disease
d. Bernard-Soulier syndrome

Accepted Answer

The answer of Explain the inheritance pattern of the following...

Exam 31: Disorders of Secondary Hemostasis

Which is the most common F-VIII mutation in patients with a severe phenotype (occurring in almost 50% of patients) ?