Hemoglobinopathy and Thalassemia (Exam 3)

Question 1

What is hemoglobinopathy?

Answer 1

abnormality of hemoglobin (either structure or subunits)

Question 2

What does the abnormal structure of Hb cause?

Answer 2

HbS (sickle cell anemia) | HbC | HbE

Question 3

What is the mechanism of hemoglobinopathy?

Answer 3

when Hb polypeptide is not normal

Question 4

What are the 2 things that hemoglobinopathy can be due to?

Answer 4

inherited abnormalities | genetic mutations

Question 5

What situation causes abnormal Hb to form crystals?

Answer 5

low pO2

Question 6

How can hemoglobinopathy lead to hemolytic anemia?

Answer 6

instable hemoglobin

Question 7

How many alpha alleles do we have on which chromosome?

Answer 7

4 co-dominant alpha alleles on chromosome 16

Question 8

Which alleles pair up with the alpha allele and which chromosome are they on?

Answer 8

beta, delta, and gamma (fetal) alleles on chromosome 11

Question 9

Because the beta and alpha hemoglobin alleles are on different chromosomes, what does this say about thalassemia?

Answer 9

can have both alpha thal and beta thal = better so alpha and beta are more equal in number

Question 10

What is the key important thing that the alpha and beta hemoglobins need to do in order to form a functioning normal hemoglobin?

Answer 10

pair up, equally | not equal = thalassemia

Question 11

If more alpha subunits are made than beta subunits, what type of thalassemia is this?

Answer 11

beta thalassemia

Question 12

If more beta subunits are made than alpha subunits, what type of thalassemia is this?

Answer 12

alpha thalassemia

Question 13

What is the cause of alpha thalassemia?

Answer 13

deletion of one or more alpha alleles

Question 14

What is the effect of 1, 2, 3, and 4 alpha allele deletions?

Answer 14

1 = asymptomatic normal carrier | 2 = slight anemia | 3 = severe anemia | 4 = would not make it past fetal stage

Question 15

At the beta allele locus, what 4 types of beta alleles can take the place of a normal beta allele?

Answer 15

beta-S | beta-C | beta-E | beta-Thal

Question 16

Which normal Hb is the most abundant in our circulation?

Answer 16

HbA1

Question 17

Which type of thalassemia (alpha or beta) is more common?

Answer 17

alpha

Question 18

What are the clinical manifestations of alpha thalassemia?

Answer 18

hypochromic, microcytic RBC

Question 19

What is an accumulation of beta 4 in alpha thalassemia?

Answer 19

HbH

Question 20

What is an accumulation of gamma 4 in alpha thalassemia?

Answer 20

Hb-Bart’s

Question 21

Who is a high risk for alpha thalassemia?

Answer 21

asians and blacks

Question 22

Which beta thalassemia type (major or minor) is more common?

Answer 22

minor

Question 23

What is the cause of beta thalassemia?

Answer 23

beta-Thal gene = genetic

Question 24

What is the cause of Beta Thalassemia Major?

Answer 24

homozygous recessive beta-Thal gene

Question 25

What are the 3 other names used to call Beta Thalassemia Major?

Answer 25

Cooley's Anemia | Thalassemia Major | Homozygous Beta-Thalassemia

Question 26

What are the 8 clinical findings of Beta Thalassemia Major?

Answer 26

hypochromic, microcytic RBC | severe form hemolytic anemia = spleenomegaly | hyperplasia BM | Alpha 4 | poikilocytosis | anisocytosis | more reticulocytes | Howell-Jolly

Question 27

Who is at higher risk for Beta Thalassemia Major?

Answer 27

white people

Question 28

When can you detect symptoms for Beta Thalassemia Major in an infant and why?

Answer 28

6 months after birth | fetus only transcribes gamma alleles in utero ... 6 months after birth = program switch from gamma to beta and detect for HbA1

Question 29

What is Beta Thalassemia Minor?

Answer 29

heterozygous beta thalassemia with slight anemia

Question 30

What are the 3 methods of treatment for Beta Thalassemia?

Answer 30

radiation of cells | gene therapy with viruses | stem cell therapy

Question 31

Why is gene therapy using viruses risky?

Answer 31

viruses can cause mutations

Question 32

What are the 2 methods in determining quantity?

Answer 32

Hb electrophoresis | chromatography

Question 33

What is Hb electrophoresis?

Answer 33

can determine the type and quantity based on the width of the banding

Question 34

What is chromatography?

Answer 34

rough estimate of quantity

Question 35

What are the 2 possible beta thal alleles?

Answer 35

beta-Thal0 and beta-Thal+

Question 36

What is beta-Thal0?

Answer 36

intermediate | total inactivation and no beta is produced

Question 37

What is beta-Thal+?

Answer 37

some normal but slightly less than normal