HEMA LEC - Alpha Thalassemias Flashcards Preview

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Flashcards in HEMA LEC - Alpha Thalassemias Deck (48)
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1

Indicates division between genes inherited from both parents

/

2

the total complement of a genes in an individual is

4

3

Indicates a gene deletion

-

4

(one gene deletion)



a+ Thalassemia

5

3 functional working genes
Called a thal 2.

a+ Thalassemia

6

two gene deletion in the same chromosome

a0 Thalassemia

7

2 functional working genes. - Called a thal 1

a0 Thalassemia

8

denotes nonfunctioning (mutated gene, not deletion) gene:

Superscript T

9

defects in alpha globin affecting the formation of both fetal and adult hemoglobins

alpha thalassemia

10

can manifest in utero because alpha chain is a component of both fetal and adult Hb

alpha thalassemia

11

more stable
do not precipitate but instead form Hb tetramers called Hb Bart

gamma chains

12

gamma chains more stable
do not precipitate but instead form Hb tetramers called ______

Hb Bart

13

Is usually caused by deletion of 1 or more of the 4 α globin genes on chromosome 16

α Thalassemia

14

physiologically useless Hb (have
very high affinity to oxygen)

Hb Bart and Hb H

15

massive edema

(hydrops fetalis)

16

_____ accumulation and deposition are more toxic than __ chain accumulation and deposition.

Alpha chain

17

which is more severe: alpha or beta thalassemia

beta thalassemia

18

clinical syndromes
-α/αα

silent carrier α thalassemia

19

treatment for silent carrier α thalassemia

none

20

detection of silent carrier α thalassemia

DNA studies

21

hgb and hct of silent carrier α thalassemia

normal

22

Caused by two missing alpha genes. May be homozygous (-α/-α) or heterozygous (--/αα).


Alpha Thalassemia Minor.

23

• Exhibits mild microcytic, hypochromic anemia.

Alpha Thalassemia Minor.

24

•     May be confused with iron deficiency anemia.

Alpha Thalassemia Minor.

25

• Although some Bart's hemoglobin (g4) present at birth, but no Bart's hemoglobin present in adults

Alpha Thalassemia Minor.

26

2nd most severe form of alpha thalassemia

Hb H disease

27

usually caused by presence of only one intact alpha gene producing alpha chains

Hb H disease

28

results in accumulation of excess unpaired gamma or beta chains
born with 10-40% Bart's Hb. Gradually replaced with Hb H
In adult, have about 5-40% Hb H

Hb H disease

29

live normal life; however, infections, pregnancy, exposure to oxidative drugs may trigger hemolytic crisis.

Hb H disease

30

RBCs: microcytic/hypochromic with marked poikilocytosis
Numerous target cells

Hb H disease

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