Hemoglobinopathies Flashcards
Hb A2 is
A2D2 (two delta chains)
*Minor adult hgb
Hb f consists of
A2Y2 (two alpha, 2 gamma)
Beta thal typically seen in what ethnicity/geographic area
Mediterranean
Bony abnormalities associated with thalassemia major
- bone marrow expansion leads to skeletal deformities with “frontal bossing,” thinning bone cortex, fractures
Lab feature of beta thal minor (trait) 1) unique lab feature
- RBC count will be very elevated
Hgb electrophoresis with two allele deletions
- normal (also normal with one allele deletion) (You make less of all hemoglobins (HbA, HBA, HBF so relative percentage doesn’t change)
African Americans and Asians in terms of typical alpha thalassemia gene deltions
a-/a- in Africans (trans)
aa/– in Asians (cis)
Path findings with hemoglobin H disease
- Hgb H is unstable and precipitates as the RBC ages, forming Heinz bodies, which causes bite cells
Bite cell differential
- G6PD
- Also Hgb H
Hemoglobin C 1) pathophysiology 2) ethnicity
1) Sixth amino acid in beta chain is changed from glutamate to lysine
2) West African
Hemoglobin C clinical features
- nonanemic
- microcytic
- splenomegaly
- mild hemolysis
Sickle beta+ thal on hgb electrophoresis
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
Sickle trait/alpha trait on hgb electrophoresis
**microcytic w/ MCV in 70s
HbA 70%
HbA2 4%
HbF 1%
HbS 25%
Sickle/HbE on electrophoresis
*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
Hgb E pathophys
- beta chain mutation leading to decreased beta chain synthesis
*it shows up as a different hgb species however on electrophoresis
Heterozygous hb lepore on electrophoresis
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
Homozygous hb lepore on electrophoresis
Hb 5-7
MCV 60s
HbF 3%
Abnormal hgb 97%
- migrates with HbS on alkaline gel
- migrates with HbA on acid gel
HbS/HPFH (hereditary persistence of fetal hgb)
- Hb 12.5
- normocytic
- HbA 0%
- HbA2 1.5%
***HbF 28.5% - HbS 70%
***So they are hgb SS but are fine
Heterogygous HPFH on hgb electrophoresis
- Hb 12.5
- MCV 78
- HbA 70%
- HbA2 2.5%
- HbF 27.5%
delta/beta thalassemia in hgb electrophoresis
all hgb F (can’t make any A2 or A1)
What is this?
Hb 12
MCV 70
HbA 85%
HbA2 1%
HbF 2%
HbS 15%
Sickledex negative
Heterozygous hemoglobin lepore
***Runs with HbS on alkaline gel but doesn’t sickle. Remember that it will look like sickle cell on hgb electrophoresis
