Deck 12: Anemias of Disordered Iron Metabolism and Heme Synthesis

Question 1

The hereditary form of sideroblastic anemia is most commonly the result of:

A)Decreased hepcidin synthesis
B)Mutation of the HFE gene
C)Abnormal ALAS
D)Increased absorption of iron

Answer 1

Abnormal ALAS

Question 2

What measurements are used in the percent saturation calculation?

A)Transferrin and ferritin
B)Ferritin and bone marrow iron
C)Serum iron and TIBC
D)Serum iron and ferritin

Answer 2

Serum iron and TIBC

Question 3

Which of the following acts as the chief regulator of iron absorption in the intestines?

A)HFE
B)Hepcidin
C)Duodenal cytochrome-B reductase
D)Ferroportin

Answer 3

Hepcidin

Question 4

A storage form of iron is:

A)Pappenheimer bodies
B)Hemoglobin
C)Ferritin
D)Transferrin

Question 5

What enzyme is responsible for reducing ferric iron to the ferrous state at the enterocyte brush border?

A)Apoferritin
B)DcytB
C)Ferritin
D)Transferrin

Question 6

Regulation of iron entering the body occurs mainly through which mechanism?

A)Transfer of iron in the enterocyte into the blood
B)Absorption of dietary iron into the enterocyte
C)Excretion of excess iron from the intestine into the urine
D)Chelation of dietary iron in the intestine

Question 7

Iron-deficiency anemia can occur from what three mechanisms?

A)Impaired iron absorption,blood loss,inadequate iron intake
B)ALAS deficiency,blood loss,decreased transferrin
C)Mutation of HFE gene,decreased transferrin,increased hepcidin
D)Inadequate iron intake,impaired iron absorption,decreased hepcidin

Question 8

What organ is the primary storage depot for iron?

A)Bone marrow
B)Duodenum
C)Stomach
D)Liver

Question 9

A term used to describe impaired utilization of iron as seen in ACD is:

A)Sideropenic
B)Sideroblastic
C)Sideroachrestic
D)Siderocyte

Question 10

Which laboratory test measures the maximum amount of iron able to be bound to transferrin in the serum?

A)Ferritin
B)Percent transferrin saturation
C)Serum iron
D)TIBC

Question 11

A 4-year-old boy who primarily eats grilled cheese sandwiches and tomato soup can suffer from iron-deficiency anemia because of:

A)Increased need
B)Inadequate intake
C)Impaired utilization
D)Increased need and inadequate intake

Question 12

What is the percent of transferrin saturation and UIBC in a patient with a serum iron of 85 mcg (µg)/dL and a TIBC of 280 ug/dL?

A)45%;280 mcg/dL
B)30%;195 mcg/dL
C)55%;195 mcg/dL
D)32%;280 mcg/dL

Question 13

An unknown sample reveals low serum iron,high TIBC,low ferritin,low hemoglobin,and a microcytic hypochromic picture in the peripheral blood.Which stage of IDA is this?

A)Stage 1 IDA
B)Stage 2 IDA
C)Stage 3 IDA
D)Cannot be determined based on the information given

Question 14

Anemia of chronic disease is characterized by:

A)A block in globin synthesis
B)An inadequate intake of iron
C)A block in insertion of iron into the porphyrin ring of heme
D)A block in iron release from macrophages

Question 15

What is the typical PB picture in a patient with stage 1 IDA?

A)Normocytic normochromic
B)Microcytic hypochromic
C)Macrocytic normochromic
D)Normocytic hypochromic

Question 16

Accumulation of heterogeneous aggregates of iron is called:

A)Hemosiderosis
B)Sideroblastosis
C)Ferritinemia
D)Transferrinuria

Question 17

Which of the following is the correct progression of iron-deficiency anemia?

A)Storage depletion,iron-poor hemoglobin production,transport depletion
B)Storage depletion,transport depletion,iron-poor hemoglobin production
C)Iron-poor hemoglobin production,transport depletion,storage depletion
D)Iron-poor hemoglobin production,storage depletion,transport depletion

Question 18

Name the molecule that is responsible for oxidizing ferrous iron to ferric iron to be combined with transferrin.

A)DCytB
B)DMT1
C)Ferroportin
D)Hephaestin

Question 19

All of the following disorders would have normal-to-elevated ferritin levels except:

A)Iron-deficiency anemia
B)Anemia of chronic disease
C)Sideroblastic anemia
D)Lead poisoning

Question 20

Which laboratory test would be most helpful in differentiating iron-deficiency anemia from anemia of chronic disease?

A)Hemoglobin
B)Serum iron
C)Percent transferrin saturation
D)Serum transferrin receptor

Question 21

The most common form of hereditary hemochromatosis is the result of which gene mutation?

A)HFE
B)Hepcidin gene
C)Ferroportin gene
D)HJV

Question 22

6-8.Use this case to answer the following questions: Hugo brought his 2-year-old son to the doctor for a checkup.He had recently moved to upstate New York from a poor neighborhood in Los Angeles.Hugo commented that his son had been very cranky lately.He attributed this condition to teething.He had a habit of chewing on his favorite painted wooden toys,which were family heirlooms.The well-baby clinic referred Hugo's son to the hospital laboratory because he was lethargic and pale.A CBC was ordered.
The patient was found to have normal serum iron studies.What other reflex test(s)should be done?

A)Blood lead level
B)Porphyrin studies
C)Reticulocyte count
D)Osmotic fragility

Question 23

Erythropoietic porphyrias are associated with:

A)Abnormal iron metabolism
B)Abnormal enzymes in the heme biosynthetic pathway
C)Abnormal globin synthesis
D)DMT1 mutations

Question 24

6-8.Use this case to answer the following questions: Hugo brought his 2-year-old son to the doctor for a checkup.He had recently moved to upstate New York from a poor neighborhood in Los Angeles.Hugo commented that his son had been very cranky lately.He attributed this condition to teething.He had a habit of chewing on his favorite painted wooden toys,which were family heirlooms.The well-baby clinic referred Hugo's son to the hospital laboratory because he was lethargic and pale.A CBC was ordered.
What is the most probable diagnosis based on these clinical findings and patient history?

A)Lead poisoning
B)Iron-deficiency anemia
C)Sideroblastic anemia
D)Hereditary hemochromatosis

Question 25

How is sideroblastic anemia confirmed by laboratory analysis?
Explain your answer.

Question 26

Alcoholics have an increased incidence of sideroblastic anemia because of which of the following?

A)Impaired utilization of globin chains
B)Abnormal stem cells
C)Abnormal activity of enzymes of heme synthesis
D)Impaired transport of iron into erythroid precursors

Question 27

A bone marrow aspirate is performed on a patient with sideroblastic anemia.The smear is stained with Prussian blue iron.The expected findings in this patient would be that iron stores:

A)Will be decreased as compared with the normal control
B)Will be the same as those in the normal control
C)Will be increased as compared with the normal control
D)Cannot be determined based on the diagnosis alone

Question 28

Note the text states 200 mcg/L in premenopausal females and 300 µg/L in men and postmenopausal women (page 220).Iron overload exists when ferritin levels are higher than:

A)100 ng/mL
B)200 ng/mL
C)50 ng/mL
D)24 ng/mL

Question 29

Differentiate between primary and secondary hemochromatosis.

Question 30

Explain the difference between the chemical composition of hemosiderin and that of ferritin.

Question 31

6-8.Use this case to answer the following questions: Hugo brought his 2-year-old son to the doctor for a checkup.He had recently moved to upstate New York from a poor neighborhood in Los Angeles.Hugo commented that his son had been very cranky lately.He attributed this condition to teething.He had a habit of chewing on his favorite painted wooden toys,which were family heirlooms.The well-baby clinic referred Hugo's son to the hospital laboratory because he was lethargic and pale.A CBC was ordered.
What reflex laboratory tests would be helpful to identify the cause of this anemia?

A)Serum iron studies
B)Vitamin B₁₂
C)Bone marrow aspirate
D)Cytogenetic studies

Question 32

Which of the following is not characteristic of iron deficiency anemia?

A)Decreased ZPP
B)Decreased serum iron
C)Increased TIBC
D)Decreased serum ferritin

Question 33

A defect in the HFE gene would cause which of the following to occur?

A)Increased iron absorption in the intestines
B)Decreased iron absorption in the intestines
C)Increased erythropoiesis in the bone marrow
D)Increased transferrin synthesis

Question 34

Explain how lead inhibits heme synthesis.

Question 35

Hypochromic,microcytic anemia is found in which stage of iron deficiency?

A)1
B)2
C)3
Correct

Question 36

Explain the absorption and assimilation of nonheme iron into hemoglobin in the RBC.