RBC and Bleeding Disorders III

Question 1

prognosis of sickle cell

Answer 1

90% survive 20yo

50% survive 50yo

Question 2

tx of sickle cel

Answer 2

DNA synthesis inhibitor

hydroxyurea

increases HbF

Question 3

chromosome 16

Answer 3

2 genes for alpha chains

Question 4

chromosome 11

Answer 4

1 gene for beta chains

Question 5

problems with thalassemias

Answer 5

Hg deficiency

AND the excess of other globin chain

decreased red cell production and lifespan
-NOT hemolysis

Question 6

mediterranean basin

Answer 6

thalassemia syndromes

also, middle east, tropical africa, india, asia

Question 7

protection against malaria

Answer 7

heterozygotes for sickle cell and thalassemias

Question 8

B0

Answer 8

absent beta globins

chain termination mutations

Question 9

B+

Answer 9

reduced beta-globins

splicing mutations and promoter region mutations

Question 10

beta-thal major

Answer 10

two thal alleles

-B0 or B+

Question 11

beta-thal major clinical

Answer 11

severe, requires blood transfusions

Question 12

beta-thal

Answer 12

mainly point mutations

Question 13

alpha-thal

Answer 13

gene deletions

Question 14

beta-thal intermedia

Answer 14

variable thal genes

some have alpha-chain defect - less severe bc less imbalance of alpha-beta

Question 15

beta-thal intermedia clinical

Answer 15

severe but no transfusions

Question 16

beta-thal minor

Answer 16

one thal allele and one normal allele

Question 17

beta-thal minor

Answer 17

asymptomatic with mild or absent anemia

RBC abnormalities

Question 18

silent carrier alpha-thal

Answer 18

1/4 alpha chains thalassemia

asymptomatic with no RBC abnormality

Question 19

alpha-thal trait

Answer 19

2/4 alpha chains thalassemia

asymptomatic

Question 20

HBH disease

Answer 20

3/4 alpha chains thalassemia

severe - but not regular transfusions

Question 21

hydrops fetalis

Answer 21

4/4 alpha chains thalassemia

lethal in utero without transfusions

Question 22

hypochromic.microcytic RBCs

Answer 22

beta-thal

Question 23

beta-thal pathology

Answer 23

diminished survival of RBCs
-due to imbalance of alpha-beta

unpaired alpha chains precipitate

membrane damage - most problems

apoptosis

Question 24

severe beta-thal

Answer 24

70-85% of RBC suffer fate of alpha chain inclusion - ineffective erythropoiesis

RBCs - splenic sequestration and extravascular hemolysis

extensive EMH, cachexia, suppression of hepcidin (too much Fe absorbed)

Question 25

immigrants from mediterranean

Answer 25

thalassemia

Question 26

beta-thal major clinical

Answer 26

6-9 months after birth - anemia
-when Hg goes to HbF to HbA

major Hg - HbF
HbA2 normal or low

requires exchange transfusions

Question 27

beta-thal major prognosis

Answer 27

wihout transfusions - death

growth retardation, enlarged cheekbones and distorted

Question 28

cardiac disease

Answer 28

iron overload in beta-thal major

tx with iron chelators

survival - third decade

Question 29

crew cut xray

Answer 29

with beta-thal major

Question 30

target cells

Answer 30

beta-thal major

Hg collects in center of cell

Question 31

basophilic stippling

Answer 31

beta-thal major

Question 32

beta-thal minor

Answer 32

more common than beta-thal major

asymptomatic with mild anemia

hypochromic, microcytic
basophilic stippling
target cells

increased HbA2 - alpha2delta2

normal HbF

Question 33

beta-thal minor resembles

Answer 33

like iron deficiency

-implications for genetic counseling

Question 34

diagnosis of beta-thal minor

Answer 34

look at serum Fe, TIBC, ferritin levels

also - HbA2 increase is diagnostically issue

Question 35

HbA2

Answer 35

alpha2delta2

Question 36

hemoglobin barts

Answer 36

gamma-4 tetramers

in newborns

hydrops fetalis - 0/4 alpha chains present

Question 37

HbH

Answer 37

beta-4 tetramers

Question 38

free beta and gamma chains

Answer 38

more soluble

-so the hemolysis is less severe in alpha-thal than beta-thal

Question 39

hydrops fetalis

Answer 39

increased O2 affinity
-fetal distress - third tromester

Hg barts - gamma4

can survive with intrauterine transfusion