Thalassemias

Question 1

Basic Thalassemia

Answer 1

Decreased Hgb, Hct
Increased RBC
Microcytic and hypochromic

Question 2

Alpha Thalassemia One Gene Deletion

Answer 2

aa/a-

Silent carries with slight microcytosis

Question 3

Alpha Thalassemia Minor

Answer 3

aa/– or a-/a-
Two gene deletion
Asymptomatic
Mild microcytic anemia with codocytes

Question 4

Alpha Thalassemia Hemoglobin H Disease

Answer 4

a-/–
Three gene deletion
Excess beta and gamma chains form tetramers
Beta tetramer = Hgb H
Gamma tetramer = Hgb Barts
Microcytic and hypochromic
See codocytes, NRBCs, poikilocytosis, Hgb H (supravital stain)

Question 5

Alpha Thalassemia Hydrops Fetalis

Answer 5

–/–
Four gene deletion
Hgb Barts and Portland produced
Incompatible with life

Question 6

Beta Thalassemia Minima

Answer 6

BSC/B
Silent carrier
Minor impact on chain production

Question 7

Beta Thalassemia Minor

Answer 7

B0/B or B+/B
Most asymptomatic
See codocytes and basophilic stippling

Question 8

Beta Thalassemia Intermedia

Answer 8

B+/B+ or B0/B+ or B0/B or BSC/BSC

Major decrease in chain production

Question 9

Beta Thalassemia Major

Answer 9

B0/B0 or B0/B+ or B+/B+
Cooley’s anemia, complete loss of chain production
Decrease in Hgb A, increase in Hgb F and a2
No tetramers
IgG binding and cells die by polychromatophilic normoblast stage
See poikilocytosis

Question 10

Hereditary Persistence of Fetal Hemoglobin

Answer 10

Form of beta thalassemia
Generally asymptomatic with slight microcytosis
Kleihauer Betke stain can show up to 100% of RBCs with Hgb F

Question 11

Hemoglobin Lepore

Answer 11

Fusion of the delta and beta chain genes
Two alpha chains with two beta-delta fusion chains
Heterozygotes are usually classified as beta thal minor
Homozygotes are usually classified as beta thal major or intermedia

Question 12

Hemoglobin Constant Spring

Answer 12

Caused by elongated alpha chains
Affects on or two of the 4 alpha genes
Clinical picture comparable to a mild form of Hgb H disease