Hemoglobinopathies

Question 1

Hb A2 is

Answer 1

A2D2 (two delta chains)
*Minor adult hgb

Question 2

Hb f consists of

Answer 2

A2Y2 (two alpha, 2 gamma)

Question 3

Beta thal typically seen in what ethnicity/geographic area

Answer 3

Mediterranean

Question 4

Bony abnormalities associated with thalassemia major

Answer 4

• bone marrow expansion leads to skeletal deformities with “frontal bossing,” thinning bone cortex, fractures

Question 5

Lab feature of beta thal minor (trait) 1) unique lab feature

Answer 5

• RBC count will be very elevated

Question 6

Hgb electrophoresis with two allele deletions

Answer 6

• normal (also normal with one allele deletion) (You make less of all hemoglobins (HbA, HBA, HBF so relative percentage doesn’t change)

Question 7

African Americans and Asians in terms of typical alpha thalassemia gene deltions

Answer 7

a-/a- in Africans (trans)
aa/– in Asians (cis)

Question 8

Path findings with hemoglobin H disease

Answer 8

• Hgb H is unstable and precipitates as the RBC ages, forming Heinz bodies, which causes bite cells

Question 9

Bite cell differential

Answer 9

• G6PD
• Also Hgb H

Question 10

Hemoglobin C 1) pathophysiology 2) ethnicity

Answer 10

1) Sixth amino acid in beta chain is changed from glutamate to lysine
2) West African

Question 11

Hemoglobin C clinical features

Answer 11

• nonanemic
• microcytic
• splenomegaly
• mild hemolysis

Question 12

Sickle beta+ thal on hgb electrophoresis

Answer 12

HbA 35% (make significantly less HbA but still some)
HBA2 4%
HBF 1%
HbS 60% (with trait it’s typically 30
***Boards loves this question

Question 13

Sickle trait/alpha trait on hgb electrophoresis

Answer 13

**microcytic w/ MCV in 70s
HbA 70%
HbA2 4%
HbF 1%
HbS 25%

Question 14

Sickle/HbE on electrophoresis

Answer 14

*Microcytic
HbA 0%
HbA2 4%
HbF 1%
HbS 47%
*abnormal hemoglobin 48%
- Migrates with HbA2 on alkaline electrophoresis (C migrates with A2) (think ACE2)
- Overlaps with HbA2 on HPLC

Question 15

Hgb E pathophys

Answer 15

• beta chain mutation leading to decreased beta chain synthesis
  *it shows up as a different hgb species however on electrophoresis

Question 16

Heterozygous hb lepore on electrophoresis

Answer 16

Hb 12
MCV 70
- HbA 85%
- HbA2 1%
- HbF 2%
-*abnormal hgb 15%
- migrates with HbS on alkaline gel
- migrates with HbA on acid gel

Question 17

Homozygous hb lepore on electrophoresis

Answer 17

Hb 5-7
MCV 60s
HbF 3%
Abnormal hgb 97%
- migrates with HbS on alkaline gel
- migrates with HbA on acid gel

Question 18

HbS/HPFH (hereditary persistence of fetal hgb)

Answer 18

• Hb 12.5
• normocytic
• HbA 0%
• HbA2 1.5%
  ***HbF 28.5%
• HbS 70%
  ***So they are hgb SS but are fine

Question 19

Heterogygous HPFH on hgb electrophoresis

Answer 19

• Hb 12.5
• MCV 78
• HbA 70%
• HbA2 2.5%
• HbF 27.5%

Question 20

delta/beta thalassemia in hgb electrophoresis

Answer 20

all hgb F (can’t make any A2 or A1)

Question 21

What is this?
Hb 12
MCV 70
HbA 85%
HbA2 1%
HbF 2%
HbS 15%
Sickledex negative

Answer 21

Heterozygous hemoglobin lepore
***Runs with HbS on alkaline gel but doesn’t sickle. Remember that it will look like sickle cell on hgb electrophoresis