Thalassemia Flashcards

1
Q

What type of disorder is thalassemia

A

genetic disorder

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2
Q

Disorder that results from abnormalities in the synthesis of the hemoglobin molecule contained in red blood cells

A

Thalassemia

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3
Q

what is the inheritance pattern of thalassemia

A

AR

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4
Q

how many genes code for alpha chain

A

4

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5
Q

how many genes code for beta chains

A

2

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6
Q

which gene is present in chromosome 16

A

alpha

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7
Q

which genes are present on chromosome 11

A

beta, gamma, delta

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8
Q

the percentage of HbA

A

97%

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9
Q

the percentage of Hb A2

A

2.5%

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10
Q

percentage of HbF

A

< 1%

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11
Q

alpha thalassemia mechanism

A

gene deletion chromosome 16

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12
Q

beta thalassemia mechanism

A

point mutation chromosome 11

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13
Q

silent career with little signs

A

a-/aa

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14
Q

–/aa

A

cis double deletion

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15
Q

-a/-a

A

trans double deletion

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16
Q

what is more common double deletion

A

cis

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17
Q

–/-a

A

HbH

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18
Q

–/–

A

Hb barts

19
Q

where is the point mutation in beta thalassemia

A

in control region

20
Q

when is beta thalassemia appear

A

when HbF gets substituted by HbA

21
Q

what indicates high Hb A2 and HbF

A

beta thalassemia

22
Q

serum fe in thalassemia

A

normal or increase

23
Q

ferritin in thalassemia

A

normal or elevated

24
Q

TIBC in thalassemia

A

normal or decreased

25
Q

% sat in thalassemia

A

N or elevated

26
Q

RBC in thalassemia

A

normal or elevated

27
Q

MCV in thalassemia

A

decreased

28
Q

MCH in thalassemia

A

decreased

29
Q

RDW in thalassemia

A

normal

30
Q

how do we diagnose Thalassemia

A

Diagnosis by molecular means if parents both known to be carriers of thalassemia

31
Q

HbF protects infants with b thalassemia until which age

A

6 months

32
Q

sickle cell beta thalassemia severity depends on

A

amount of b globe synthesis

33
Q

when does a patient with b thalassemia be subjected to aplastic anemia

A

secondary to infection with parvovirus b19

34
Q

diagnosis 6-24 months most probably is

A

beta thalassemia major

35
Q

diagnosis 2-6 years most probably is

A

b/ a thalassemia minor or intermedia

36
Q

coombs test in thalassemia is

A

negative

37
Q

in thalassemia haptoglobin will be

A

decreased

38
Q

confirmatory diagnostic studies

A

hb electrophoresis
automated HPLC
genetic studies (pcr based)
bone marrow aspiration

39
Q

patient with HbA2 >3.5%

A

b thalassemia minor

40
Q

skull xray features

A

chipmunk face
crew cut sign

41
Q

Management in Thalassemia minor

A

-Usually no treatment required
-Episodic folic acid supplementation may be indicated (e.g., during pregnancy, acute infections)

42
Q

Management in thalassemia major and intermedia

A
  1. Transfusion therapy (erythrocyte concentrates)
    -Indication (for transfusion-dependent thalassemias): Hb < 7 g/dL or marked clinical symptoms
    -Target: Hb > 9–10 g/dL
  2. Surveillance and treatment of complications
    -Iron overload diseases: chelating agents, e.g., deferasirox, indicated when iron accumulation reaches toxic levels
    -Other complications: e.g., gallstones, asplenia, extramedullary hematopoietic pseudotumors
43
Q

Management of thalassemia in select patients

A
  1. Splenectomy
  2. Potentially curative treatment
    -Stem cell transplantation: allogenic HSCT
    -Gene therapy