HEMA LEC - Thalassemias Flashcards Preview

► Med Misc 05 > HEMA LEC - Thalassemias > Flashcards

Flashcards in HEMA LEC - Thalassemias Deck (46):
1

group of inherited disorders causing genetic mutations that reduce or prevent synthesis of one or more globin chain

thalassemis

2

thalassemia is characterized by __ rbcs

microcytic/hypochromic

3

first described children with anemia

thomas cooley and pearl lee

4

nonspecific or general classif of thal
severe course of thalasemia
either no alpha or beta chain produced

homozygous

5

nonspecific or general classif of thal
milder anemia; carriers

heterozygous

6

defects that cause a decrease or absent production of particular globin [3]

point mutation
small insertions or deletions
large deletions

7

specific thal categories

alpha thalassemia
beta thalassemia

8

premature death of rbc precurosrs in BM

ineffective erythropoiesis

9

anemia in thalassemia is due to 2 main components

ineffective erythropoiesis
extravascular hemolysis in RES esp spleen

10

imperfect extravascular hemolysis produces __

nucRBCs and tear drop rbcs

11

mildest form of B thal

silent carrier state

12

heterozygous disorder resulting in mild hypochromic, microcytic, hemolytic anemia

B thalassemia minor

13

severity lies between major and minor

B thalassemia intermedia

14

homozygous disorder resulting in severe life long transfusion-dependent hemolytic anemia

B thalassemia major

15

thalassemias are Named according to the ?

chain with reduced or absent synthesis

16

Decreased or absent synthesis of one of the globin gene
chains not only leads to decreased but also ________


in imbalance in the alpha/beta chain ratio hb
production

17

third component that contributes to the severity of anemia that may also worsen the anemia

splenomegaly

18

how may splenomegaly worsen anemia

bec of 2 components:
1) increased sequestration
2) increased plasma volume caused by splenomegaly (dilutional)

19

____occurs, which also contributes for the splenomegaly,

Extramedullary erythropoiesis

20

Are various heterozygous (from one parent) β gene mutations that produce only small decrease in production of β globin chains.
•   Patients have nearly normal alpha/beta chain ratio and no hematologic abnormalities.
• Have normal levels of HbA2

Silent Carrier State for β-Thalassemia

21

Decreased rate of synthesis of one of the beta chains; other beta chain normal


β Thalassemia Minor (Trait)

22

• Caused by heterozygous (from one parent) mutations that affect β globin synthesis.

β Thalassemia Minor (Trait)

23

• β Chains production and thus Hb-A production is more reduced than the silent carrier Hb-A.

β Thalassemia Minor (Trait)

24

•       Have one normal β gene and one mutated β gene.

β Thalassemia Minor (Trait)

25

• Usually presents as mild, asymptomatic hemolytic anemia unless patient in under stress such as pregnancy, infection, or folic acid deficiency.

β Thalassemia Minor (Trait) or B thalassemia Intermedia

26

anemia usually hypochromic and microcytic w/ slight aniso and poik, including target cells and elliptocytes; may also see basophilic stippling

β Thalassemia Minor (Trait)

27

rarely see hepatomegaly or splenomegaly

β Thalassemia Minor (Trait)

28

have high Hb A2 levels (3.6-8.0%) and normal to slightly elevated HbF levels

β Thalassemia Minor (Trait)

29

B thalassemia that normally requires no treatment

β Thalassemia Minor (Trait)

30

confused with IDA

β Thalassemia Minor (Trait)

31

uses Mentzer index

β Thalassemia Minor (Trait)

32

markedly decrease rate of synthesis or absence of both beta chains results in an excess of alpha chains, no Hgb A can be produced; compensate with up to 90% Hgb F

β Thalassemia Major/Cooley's Anemia

33

Excess alpha chains precipitate on the RBC membrane, form Heinz bodies, and cause rigidity; destroyed in the bone marrow or removed by the spleen

β Thalassemia Major/Cooley's Anemia

34

Symptomatic by 6 months of age; hepatosplenomegaly, stunted growth, jaundice, prominent facial bones (Esp cheek and jaw); iron overload from RBC destruction and multiple transfusions cause organ failure

β Thalassemia Major/Cooley's Anemia

35

profound anemia stimulates an increase in EPO production by kidneys and results in massive but ineffective erythroid hyperplasia

β Thalassemia Major/Cooley's Anemia

36

marked bone changes and deformities occur due to massive BM expansion

β Thalassemia Major/Cooley's Anemia

37

thalassemia major life expectancy
Without regular transfusion –

Less than 10 years

38

thalassemia major life expectancy
With regular transfusion and no or poor iron chelation

Less than 25 years

39

thalassemia major life expectancy
With regular transfusion and good iron chelation

40 years, or longer??

40

iron chelator

desferoxamine

41

Have varying symptoms of anemia, jaundice, splenomegaly and hepatomegaly

B thalassemia intermedia

42

have significant increase in bilirubin levels

B thalassemia intermedia

43

anemia usually becomes worse with infections, pregnancy or folic acid deficiency

β Thalassemia Minor (Trait) or B thalassemia intermedie

44

MAY become transfusion dependent

B thalassemia intermedia

45

tend to develop iron overloads as a result of increased gastrointestinal absorption

B thalassemia intermedia

46

usually survive into adulthood

B thalassemia intermedia

Decks in ► Med Misc 05 Class (295):