Deck 10: Hemolytic Anemias: Intracorpuscular Defects: II Hereditary Enzyme Deficiencies

Question 1

Which red cell inclusion is characteristic of G6PD deficiency?

A) Cabot ring
B) Howell-Jolly body
C) Heinz body
D) Pappenheimer bodies
E) Siderotic granule

Answer 1

Heinz body

Question 2

Which of the following types of G6PD enzyme is the most common form in all populations and exists in 99% of whites in the United States?

A) Gd A+
B) Gd A-
C) Gd Med
D) Gd B
E) Gd Canton

Answer 2

Gd B

Question 3

Which of the following is a screening test for G6PD deficiency?

A) Heinz body stain
B) Methemoglobin reduction test
C) Ascorbate-cyanide test
D) All of the above
E) None of the above

Answer 3

All of the above

Question 4

Which of the following is characteristic of PK deficiency?

A) The severity of the hemolytic anemia varies widely
B) Varying degrees of polychromasia and poikilocytosis may be found on the peripheral smear and nucleated red cells may be seen
C) Clinical manifestations commonly found include splenomegaly and cholelithiasis
D) Onset may be during infancy or early childhood and mild cases may not be detected until adulthood
E) All of the above

Question 5

The diagnosis of G6PD deficiency in a black man during acute hemolysis may be difficult to detect in a screening test due to:

A) The increased number of younger red cells (reticulocytes) that have normal levels of G6PD and a lack of older G6PD-deficient red cells due to hemolysis
B) Drug interference in the testing
C) Too many G6PD-deficient red cells
D) Too many white blood cells
E) Too many platelets

Question 6

A laboratory result that would suggest a PK deficiency on a 20-year-old patient is/are?

A) Negative direct antiglobulin test (DAT)
B) Abnormal autohemolysis test uncorrected by the addition of glucose
C) Normal osmotic fragility test in freshly drawn blood
D) All of the above
E) None of the above

Question 7

Which of the following most often represents the pattern of inheritance for pyruvate kinase deficiency?

A) Autosomal dominant
B) Autosomal recessive
C) X-linked
D) Co-dominant
E) Any of the above

Question 8

Which of the following represents the pattern of inheritance of G6PD deficiency?

A) Autosomal dominant
B) Autosomal recessive
C) X-linked
D) Any of the above
E) None of the above

Question 9

Hemolysis induced by drugs is a clinical feature commonly seen in which G6PD deficiency?

A) Gd A-
B) Gd Med
C) Both
D) Neither

Question 10

Hemolysis induced by infection is a clinical feature commonly seen in which G6PD deficiency?

A) Gd A-
B) Gd Med
C) Both
D) Neither

Question 11

What is the major clinical feature of a patient with methemoglobinemia?

A) Reticulocytosis
B) Cyanosis
C) Splenomegaly
D) Pallor
E) Favism

Question 12

Which variant of the G6PD enzyme is commonly found in the Chinese and in people of Southeast Asia?

A) Gd A+
B) Gd A-
C) Gd Med
D) Gd B
E) Gd Canton

Question 13

Which G6PD enzyme commonly found in Africans has normal activity but differs from that found in whites by a single amino acid substitution that alters its electrophoretic mobility?

A) Gd A+
B) Gd A-
C) Gd Med
D) Gd B
E) Gd Canton

Question 14

Which of the following represents the second most frequently encountered enzyme deficiency that causes a hemolytic anemia?

A) Hexokinase
B) Lactic dehydrogenase
C) Pyruvate kinase
D) Glucose 6-phosphate dehydrogenase
E) None of the above

Question 15

Patients with which type of G6PD deficiency present with chronic hemolysis?

A) Gd A-
B) Gd Med
C) Both
D) Neither

Question 16

The presence of Heinz bodies is related to which enzyme deficiency?

A) Gd A-
B) Gd Med
C) Pyruvate kinase
D) Two of the above
E) All of the above

Question 17

Which of the following can cause methemoglobinemia?

A) Hereditary enzyme deficiency of NADH-methemoglobin reductase
B) Exposure to strong oxidizing drugs or toxic substances
C) Hemoglobin M disease
D) All of the above
E) None of the above

Question 18

Which of the following forms of G6PD enzymes is the product of a mutant gene located on the X chromosome resulting in a G6PD deficiency that occurs in 10-15% of American blacks?

A) Gd A+
B) Gd A-
C) Gd Med
D) Gd B
E) Gd Canton

Question 19

Favism is a clinical feature that occasionally occurs in which G6PD deficiency?

A) Gd A-
B) Gd Med
C) Both
D) Neither

Question 20

Occasionally transfusions may be required in which type of G6PD deficiency?

A) Gd A-
B) Gd Med
C) Both
D) Neither