Hemoglobins Flashcards
More common in Alpha-thal: Mutation or deletions?
In B-thal?
Alpha: Deletions (–/–)= Hg Barts
Beta: Point mutations
Lab findings to ddx Alpha Thal from Iron deficency?
What is Hg H?
Both have lowered MCV wit hypochromic anemia, a-thal has increased RBC count
Hg H: (–/-a) from compount heterozygous with B-chain tetromers; makes Heinz bodies
Lab findings in b-thal heterozygotes?
Findings in b-thal homozygotes?
When do these findings show up in life?
Hetero: most asymptomatic: Microcytosis without structural hemoglobin variant
Increased A2 and or increased Hb F (5-20%).
Homo: Severe anemia and alpha tetramers. Skelatal changes, hepatospelenomegaly and infections?
After 6 months when Hb F decreases (alpha earlier as it is part of F)
Microcytosis and erythroocytosis with Normal A2 and increased Hb F, think of what entity?
What is Hb Lepore (hetero vs homo)?
Delta-Beta Thal; Hetero have Hb F 5-20%
Homo: 100% Hb F
Lepore: Fusion of 5’ delta to 3’ beta to make fused delta-beta under weak delta promoters
Hetero: 6-10% Hb Lepore and mild features
Homo: 90% Hb F and 10% Lepore
Sickle cell mutation?
Homo vs Hetero percentages of mutant Hb’s?
Beta: Glu6Val
Hetero: Tend to have 25% Variant; Homo 50%
Rank 4 HbS (including b-thal) in severity?
Lab findings in Hb S/Bo
Hb SS, Hb S/Bo, Hb SC, Hb S/B+
SE, SD-Punjab, SO-Arab can cause sickling
S/Bo: Differs from SS: Has microcytosis, increased Hb A2
Hb C mutation?
Hetero/Homo findings?
B: Glu6Lys
Hetero: Asymptomatic; target and crystals ~50/50%
Homo: Mild chronic hemolsyis, splenomegaly and gallstones (90% C, 0% S)5
Can cause hemolysis with S, D, O
What is Hb D-Punjab?
Hard to ddx from what other Hb?
D: Beta variant asymptomatic in hetero and homo
Hb G (alpha asymptomatic mutation): They migrate similar on HPLC and in acid gels HPLC has 2nd G band and can use isoelectric focusing
What is Hb E/ A2 percent?
Homo/Hetero?
What is SE?
E: Beta chain variant with reduced synthesis; A2 >10% (if less think B-thal)
Hetero E: aymptomatic
Homo: reduced MCV and target cells
SE: Can sickle, less severe than SS and has variable anemia
What is Hb Constant Spring?
Constant Spring: Southeast Asia: Mutation in last codon of A2-globin
Leads to 31 amino acids added and decreased rate of synthesis
Hetero: Asympto
Homo: Mild microcytosis andhypochromasia and mild hemolysis
If with H: severe anemia
Hb S level differences in SA/a-thal vs SA/B-thal?
Acid Gel–what runs together?
Basic gel–what runs together?
A, A2, G, E: AGED
HPLC fails to separate?
E, A2, C or O-Arab
What is Methemoglobin/ Hi?
Ironin Ferric (+3) state instead of (+2)
Chocolate brown blood
Tx: Methylene blue
F, A, A2 chains made of?
F: 2a2y
A: 2a2b
A2; 2a2d
