12. Hemoglobinopathies

Question 1

Most common cause of hemoglobinopathies

Answer 1

Amino acid substitutions in the β-globin chains

Question 2

Mutation in Hgb S

Answer 2

β6(Glu–>Val)

Question 3

Race where Hgb S is seen

Answer 3

African

Question 4

Homozygous for Hgb S

Answer 4

Sickle cell disease

Question 5

RBC morphologies seen in sickle cell disease

Answer 5

• normocytic/normochromic

- drepanocytes

Question 6

WBC count in sickle cell disease

Answer 6

Elevated

Question 7

Retic count in sickle cell disease

Answer 7

Elevated

Question 8

Sickle screen is AKA

Answer 8

Dithionite solubility

Question 9

Dithionite solubility of sickle cell disease

Answer 9

Positive

Question 10

In Hgb electrophoresis of sickle cell disease, what hgb is present? What Hgb is absent?

Answer 10

Present: Hgb S
Absent: Hgb A

Question 11

Other methods for demonstrating Hgb S

Answer 11

HPLC

Isoelectric focusing

Question 12

Used to help retain Hgb F production

Answer 12

Hydroxyurea

Question 13

What situation do sickle cells form?

Answer 13

When O2 saturation decreases

Question 14

Heterozygous for Hgb S

Answer 14

Sickle cell trait

Question 15

Majority of Hgb present in sickle cell trait

Answer 15

Hgb A

Question 16

Dithionite solubility of sickle cell trait

Answer 16

Positive

Question 17

In Hgb electrophoresis of sickle cell trait, what Hgbs are present?

Answer 17

Present: Hgb A & Hgb S

Question 18

Mutation in Hgb C

Answer 18

β6(Glu–>Lys)

Question 19

Characteristics of Hgb C

Answer 19

Thick crystals resembling bars of gold or the Washington Monument

Question 20

Dithionite solubility of Hgb C

Answer 20

Negative

Question 21

Hgbs seen during Hgb electrophoresis of Hgb C

Answer 21

Homozygous: Hgb C
Heterozygous: Hgb A & C

Question 22

Hgb characterized by a double mutation [β6(Glu–>Val) and β73(Asn–>Asp)] and is clinically significant if inherite in combination with Hgb S

Answer 22

Hgb C-Harlem

Question 23

Muation seen in Hgb C-Harlem

Answer 23

β6(Glu–>Val) and β73(Asn–>Asp)

Question 24

Muation in Hgb E

Answer 24

β26(Glu–>Val)

Question 25

RBC morphology seen in Hgb E

Answer 25

Microcytes

Target cells

Question 26

Dithionite solubility of Hgb E

Answer 26

Negative

Question 27

Combination disorder with inheritance of mutations for both Hgb S and Hgb C

Answer 27

Hgb SC

Question 28

Most common of the compound Hgb disorders

Answer 28

Hgb SC

Question 29

Crystalline structure resembling birds or fingers

Answer 29

Hgb SC

Question 30

Dithionite solubility of Hgb SC

Answer 30

Positive

Question 31

Hgbs seen during Hgb electrophoresis and HPLC of Hgb SC

Answer 31

Hgb S & C

Question 32

RBC morphology seen in Hgb SC

Answer 32

Target cells

Hgb SC crystals

Question 33

Disorders resulting from genetic mutations that lead to structural changes in th Hgb molecule

Answer 33

Hemoglobinopathies