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
