Hemoglobinopathies and Thalassemia Flashcards

1
Q

clinical manifestations thalessemia

A

anemia, chronic hemolysis, microcytic hypochromic, ineffective erythropoesis. Splenomegaly, functional hyposplenism.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

extramedullary erythropoesis in thal causes

A

masses large enough to cause compression syndromes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

lab findings thal

A

decreased MCV, hemoglobin, MCH, MCHC, microcytic hypochromic, presence high affinity hemoglobins, increased EV hemolysis, extramedullary hematopoeisis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Mentzer index

A

differentiate thal from IDA. Divide MCV / RBC #. If < 13 favors thal. If > 13 favors IDA. Iron studies should also be performed. Perform hemoglobin electrophoresis. Sequencing for hemoglobin types, dot blot assays first.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

alpha gene genetics

A

2 a genes located on each of chromosome 16. A2 located upstream and produces 2-3 times more mRNA than A1 downstream.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

all 4 alpha genes mutated

A

hydrops fetalis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

3 alpha chains mutated

A

HBH disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

deletion 2 genes

A

thalassemia minor.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

deletion 1 gene

A

silent carrier.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

difference hemoblobinopathies thal

A

thal RBC count increased over what is expected, opathies normocytic normochromic, thal microcytic microchromic. sickles cells and crystals in opathies. Solubility test + in opathies, - in thal. Retic increased more in opathies. `HBH HB barts present.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Gamma clobin tetramers

A

barts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Deletional more common in

A

alpha genes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

non deletional more common in

A

beta chains. ie promoter nonsense, stop codon, splice site.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

beta gene genetics

A

located on chromosome 11 only one beta gene from each parent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

target cells

A

increase in beta thalassemia major. anemia is also more severe.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

A and F hemoglobin relationship in thalassemia

A

as aanemia sd severity increases from minor to major, A decreases F increases. Can be seen on electrophoresis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

increase in F

A

increased oxygen affinity for F decreases delivery to tissues.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Beta thalassemia

A

increased alpha chains cause precipitation, damage rbc membrane, cause ineffective erythropoeisis and IV EV destruction, SPLENOMEGALY, INCREASE EPO, EXTRAMEDULLARY ERYTHROPOEISIS. INCREASE IRON, TOXICITY.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

target cells in thal due to

A

decrease in hemoglobin without corresponding decrease in membrane.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

reticulocyte count lower than expected in thal due to:

A

ineffective erythropoeisis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

hb constant spring

A

alpha chain elongated by 31 amino acids. homozygs mild anemia hetero asymptomatic.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

hb lepore

A

hybrid beta-delta chain fusion. Alpha chains have nothing to associate with cause hemolysis like beta thal.

23
Q

Hereditary persistence of fetal hemoglob

A

increase in gamma chains to compensate for absence of beta dlta chains. HBF common. Mostly asymptomatic.

24
Q

HBS Pathology

A

GLU-> Val mutation on surface causes less polar and less soluble in deoxy state. Reversible on oxygenation. Delays means most blood cells do not sickle, but sickle in spleen kidney and other hypoxic acidic

25
Q

HBA

A

A2B2 normal adult

26
Q

Gower 1

A

psi epsilon embryonic

27
Q

Gower II

A

A epsilon embryonic

28
Q

Portland

A

Psi2 gamma 2 embryonic

29
Q

HBF

A

alpha 2 gamma 2

30
Q

HBA2

A

alpha2 delta 2

31
Q

Hemoglobin chain ovef maturation

A

switch from psi to alpha, and epislon (E) to gamma (F) to B(adult)

32
Q

test for hemoglobinopathies:

A

electrophoresis, HPLC PCR, solubility test, heat precipitation test, tests for Heinz bodies.

33
Q

Mutation for HB S, C and E

A

ALL GLUTAMIC ACID NEGATIVE CHARGE. S IS NON POLAR VAL, WHILE E AND C ARE POSITIVELY CHARGED LYS.

34
Q

HBS BLOOD SMEAR

A

NORMOCYTIC NORMOCHROMIC, SICKLE CELLS

35
Q

HBE BLOOD SMEAR

A

MICROCYTIC MICROCHROMIC, TARGET CELLS

36
Q

HBC

A

NORMOCYTIC AND CHROMIC RETICULOCYTOSIS TARGET CELLS

37
Q

SICKLE CELL DISEASE ASSOCIATED WITH

A

EV HEMOLYSIS. RPI 3-5 X TO COMPENSATE.

38
Q

HBS OXYGEN AFFINITY

A

LOWER. BUT POLYMERIZES LEADING TO PREMATURE DESTRUCTION.

39
Q

SICKLING HAPPENS UPON

A

DEOXYGENATION, REVERSES ON OXYGENATION. MORE PRONE TO OXIDATION. LEADS TO LOSS OF WATER, DESTRUCTION OF MEMBRANE LATTICE PROTEINS, DECREASES DEFORMABILITY, CATION PROTEINS, EV HEMOLYSIS.

40
Q

VASO OCCLUSIVE CRISIS

A

DEOXYGENATION, BLOCKAGE, REPEATED DEOXYGENATION FROM ANEMIC TISSUE AHEAD OF BLOCKAGE.

41
Q

AUTOSLPENECTOMY

A

EXTENSIVE EV HEMOLYSIS DECREASES OXYGEN TO SPLEEN, LEADING TO DECREASED FUNCTION.

42
Q

HYDROXYUREA BOOSTS

A

HBF PRODUCTION

43
Q

HEMOGLOBIN CRYSTAL

A

MILD TO MODERATE, NO VASOOCCLUSIVE CRISIS. HEMOGLOBIN CRYSTALS FORM. HB S / C HETEROZYGOUS IIS INTERMEDIATE BETWEEN BOTH DISEASES. mORE S BECAUSE S IS MORE NEGATIVELY CHARGED.

44
Q

HEMOGLOBIN E

A

MILD ASYMPTOMATIC ANEMIA.

45
Q

METHHEMOGLOBINEMIA

A

OXIDIZED HEMOGLOBIN IS METHHEMOGLOBIN, CANNOT BIND OXYGEN. kEPT REDUCED BY METHHEMOGLOBIN REDUCTASE.>1%.

46
Q

CAUSES METHHEMOGLOBINEMIA

A

ACQUIRED, REDUCTION PATHWAY OVERWHELMED.

OR CONGENITAL. DEFECT IN PATHWAY, OR STRUCUTURAL ABNORMALITY, HBM.

47
Q

HBM CAUSES

A

PSUEDOCYANOSIS.

48
Q

HBH

A

BETA TETRAMERS

49
Q

HB BARTS

A

GAMMA TETRAMERS

50
Q

CHRONIC HEMOLYSIS IN HBH

A

PRECIPITATES OF HBH TRIGGER HEMOLYSIS

51
Q

BETA+

A

PARTIAL BLOCK OF BETA CHAIN SYNTHESIS

52
Q

BETA0

A

FULL BLOCK OF BETA CHIAN SYNTHESIS.

53
Q

BETA THALASSEMIA BLOOD PICTURE

A

TARGET CELLS SCHISTOCYTES, RETICS LOWER THAN EXPECTED DUE TO INEFFECTIVE ERYTHROPOESIS