Defects of Globin synthesis

Question 1

What is quantitative globin defect

Answer 1

Not enough globin chains are made. Includes thalassemia

Question 2

What is qualitative globin defect

Answer 2

Correct number of globin chains but they function abnormally. Hemoglobinopathy

Question 3

HbA chain makeup

Answer 3

2 alpha and 2 beta chains

Question 4

HbA2 chain makeup

Answer 4

2 alpha and 2 delta chains

Question 5

HbF chain makeup

Answer 5

2 alpha and 2 gamma chains

Question 6

What is thalassemia

Answer 6

Deletion or inactivation of globin chain gene that leads to decreased production of one or more globin chains

Question 7

Causes of thalassemia

Answer 7

full or partial gene deletion, point mutations

Question 8

Complications of thalassemia

Answer 8

decreases Hb production, overproduction of non-affected globin chains, disrupts ratio of chains, hypo micro anemia

Question 9

How many loci of alpha chains and what chromosome

Answer 9

4 loci, chromosome 16

Question 10

How many loci of beta chains and what chromosome

Answer 10

2 loci, chromosome 11

Question 11

What globin chains in HbH

Answer 11

4 beta chains

Question 12

What globin chains in Hb Barts

Answer 12

4 gamma

Question 13

What hemoglobins can be made in alpha thalassemia

Answer 13

HbH and Hb Barts

Question 14

What problems arise with HbH and Barts?

Answer 14

Unstable so inc rate of precipitation in cytoplasm. High O2 affinity, and carries an insignificant amount of O2

Question 15

What is HbH stained with

Answer 15

Brilliant cresyl blue

Question 16

Hydrops fetalis

Answer 16

Incompatible with human life. Occurs when there are 4 alpha chain deletions.

Question 17

Silent beta thalassemia

Answer 17

Partial deletion of one gene. Asymptomatic, no detectable anemia

Question 18

Minor beta thalassemia

Answer 18

1 deletion, asymptomatic unless there is a significant stressor like illness or surgery

Question 19

intermediate beta thalassemia

Answer 19

partial deletion of one or more genes, moderate anemia

Question 20

Major beta thalassemia

Answer 20

2 deletions, called cooleys anemia

Question 21

What hemoglobins are associated with Beta thalassemia

Answer 21

HbA2 and HbF

Question 22

Peripheral blood picture of beta thalassemia

Answer 22

nRBC, tear drop, target cells, baso stippling, hypochromia, microcytosis, schistocyte, ovalocyte, siderotic granules, Howell-jolly

Question 23

Blood pic for minor beta thalassemia

Answer 23

mild hypo micro, targets, ovalocytes, tear drops and baso stippling

Question 24

What happens with an increase in EPO

Answer 24

Erythroid hyperplasia, increased cellularity in the bone marrow. Can cause frontal bossing

Question 25

What amino acid substitution is in sickle cell anemia?

Answer 25

Valine is substituted for glutamic acid

Question 26

Difference between sickle cell trait and sickle cell anemia

Answer 26

Trait has 1 mutated beta gene, is heterozygous and less severe. Usually no sickle cells on smear Anemia has 2 mutated beta genes, homozygous and extremely severe. Always sickle cells on smear

Question 27

Characteristics of sickle cell in peripheral blood

Answer 27

sickle, target, nRBC, inclusions

Question 28

Bone marrow in sickle cell anemia

Answer 28

reticulocytosis, hyperplasia

Question 29

Acute chest syndrome

Answer 29

Symptoms: fever, respiratory, lung infiltrates Second most common cause of hospitalization. Occurs within 1-3 days of vasoocclusive crisis

Question 30

Other complications of sickle cell

Answer 30

Autosplenectomy, aplastic crisis, massive extravascular hemolysis

Question 31

Hemoglobin C disease substitution

Answer 31

Lysine is substituted for glutamic acid

Question 32

Hemoglobin C disease blood picture

Answer 32

Pocketbook cells with junky looking target cells

Question 33

Hemoglobin SC disease

Answer 33

marriage of HbS and HbC with dense pointy irregular crystals and moderate hemolytic anemia

Question 34

Beta thal minor Hb production

Answer 34

less total HbA than normal

Question 35

Sickle cell trait Hb creation

Answer 35

More HbA than HbS

Question 36

Beta thal minor / sickle cell trait Hb production

Answer 36

More HbS than HbA

Question 37

How are defects of globin synthesis diagnosed

Answer 37

Hemoglobin electrophoresis, global prevalence etc

Question 38

Differential diagnosis alpha vs beta thalassemia

Answer 38

Alpha: symptoms at birth. Cant make HbF, 3+ deletions only Beta: no symptoms until 6 months. Large amounts of HbF until then