hemoglobinopathy Flashcards
What are the normal hemoglobin electrophoresis findings in healthy adults?
Hgb FA on newborn screen.
Hgb A (α₂β₂): >95%
Hgb A2 (α₂δ₂): <3.5%
Hgb F (α₂γ₂): <2%
What are the normal hemoglobin electrophoresis findings in healthy newborns?
Hgb F (α₂γ₂): 90%
Hgb A (α₂β₂): 10%
Hgb A2 (α₂δ₂): 0%
What are the hemoglobin electrophoresis findings in adults with sickle cell trait?
Hgb A: 60%
Hgb S: 40%
Hgb F: <2%
Hgb A2: <3.5%
What are the newborn screening results for sickle cell trait?
Hgb FAS
Hgb F: 90%
Hgb A: 7%
Hgb S: 3%
What are the hemoglobin electrophoresis findings in adults with sickle cell disease (Hgb SS)?
Hgb S: 90%
Hgb F: 5-9%
Hgb A: 0%
Hgb A2: <3.5%
What are the newborn screening results for sickle cell disease (Hgb SS)?
Hgb FS
Hgb F: 90%
Hgb S: 10%
What are the hemoglobin electrophoresis findings in β-thalassemia major?
Hgb F: >90%
Hgb A: 0%
Hgb A2: <3.5%
What is the newborn screening result for β-thalassemia major?
Hgb F
Hgb F: 100%
What are the hemoglobin electrophoresis findings in β-thalassemia minor (trait)?
Hgb A: 85%
Hgb A2: 5-7%
Hgb F: 5-7%
What is the newborn screening result for β-thalassemia minor (trait)?
Hgb FA
Hgb F: 90%
Hgb A: 10%
What are the hemoglobin electrophoresis findings in Hemoglobin CC disease (Hgb CC)?
Hgb C: 95%
Hgb A2: <3.5%
Hgb F: <3%
Hgb A: 0%
What is the newborn screening result for Hgb CC disease?
Hgb FC
Hgb F: 90%
Hgb C: 10%
What are the hemoglobin electrophoresis findings in Hemoglobin SC disease (Hgb SC)?
Hgb S: 45%
Hgb C: 45%
Hgb F: 5-9%
Hgb A: 0%
What is the newborn screening result for Hgb SC disease?
Hgb FSC
Hgb F: 85%
Hgb C: 5-9%
Hgb S: 5-9%
What is the newborn screening result for Hgb S/β⁰ (Sickle Cell-β⁰ Thalassemia)?
Hgb FS → needs parental testing
Hgb F: 90%
Hgb S: 10%
What is the newborn screening result for Hgb S/β⁺ (Sickle Cell-β⁺ Thalassemia)?
Hgb FSA
Hgb F: 90%
Hgb S: 7%
Hgb A: 3%
What are the hemoglobin electrophoresis findings in γδβ-thalassemia homozygous?
Hgb F: 97-99%
Hgb A: 0%
Hgb A2: 0%
What is the newborn screening result for γδβ-thalassemia homozygous?
Hgb F
Hgb F: 100%
Hemoglobin Constant Spring (CS)
Etiology: stop codon mutation in an alpha globin gene resulting in production of an abnormally long alpha globin molecule. The abnormal alpha globin results in chain imbalance leading to red cell instability.
In the heterozygous state, only about 1% to 2% Hb CS is found in the peripheral blood. Homozygous Hb CS creates a thalassemia intermedia phenotype.
Because of it’s larger size, Hb CS forms a slow-moving band on electrophoresis.
On hemoglobin electrophoresis, the Hb E and Hb O Arab bands travel similarly to the Hb C band, and the Hb G band similarly to Hb S. Hb H is a fast-moving band.
Hgb electrophresis fastest to slowest.
H > A > F > G, S, D > C E O > Costant spring
h high up
AF
GSD
CEO
constant spring
In alkaline pH it had electrophoretic mobility similar to Hb S
In acid pH, migration resembled Hb A.
hgb D
Hereditary persistence of fetal hemoglobin (HPFH).
a benign condition with a wide range of hemoglobin F production from a few percentage in nondeletional HPFH, which produces heterocellular hemoglobin F, to up to 30% in deletional HPFH with pancellular hemoglobin F production.
Fetal hemoglobin (hemoglobin F [alpha2 gamma2]) is the major hemoglobin present during gestation and constitutes approximately 60% to 80% of total hemoglobin in the full-term newborn. After birth, a hemoglobin switch occurs, and gamma globin production decreases while beta globin increases, leading to increasing levels of adult hemoglobin, or hemoglobin A. Most people have less than 2% hemoglobin F by the time they are 2 years old.
