Hemoglobin Chains

Question 1

Hgb A

Answer 1

2 alpha chains, 2 beta chains

90% of adults

Question 2

Hbg A2

Answer 2

2 alpha chains, 2 delta chains

1-3% of adults

Question 3

Hgb F

Answer 3

Two alpha chains, 2 gamma chains

50-90% in fetal/babies, 1-3% adults

Question 4

Hgb S

Answer 4

Mutation:

Valine sub for glutamic acid at 6th position of beta chain.

Question 5

Hgb C

Answer 5

Mutation:

Lysine sub for glutamic acid at 6th position on beta chain

Question 6

Hgb H

Answer 6

3 alpha chains deleted –> gamma chains initially increase, then beta chains increase
= BETA CHAIN TETRAMERS (4 beta chains)

Hemoglobin H Disease

Question 7

Hgb Bart’s

Answer 7

4 alpha chains deleted / NO alpha chains

Hbg Barts is FOUR fetal hemoglobin chains (4 gammas) = incompatible with life, Hydrop’s Fetalis

Question 8

What is fetal hemoglobin?

Answer 8

Gamma hemoglobin chain

Question 9

Hgb E

Answer 9

Lysine sub for glutamic acid at 26th position of beta chain

Common in Southeast Asians and Indians

Question 10

Hgb Portland

Answer 10

Embryonic hemoglobin

2 zeta chains, 2 gamma chains

Question 11

What hemoglobin chains are embryonic?

Answer 11

Hgb Portland  (2 zeta, 2 gamma)
Hgb Gower (2 zeta, 2 epsilon)