12 Thalassemia
Globin
alpha chain very important: component of all 3 types
beta thalassemia only affects A
sample from patient in gel with electrical charge
Thalassemia
decreased hemoglobin causes thalassemia
Alpha
top right: normal, 2 alpha on each copy of Ch 16
alpha: gene deletion
depending on number missing, severity
if not lead poisoning, sideroblastic, or iron, suspect thalassemia
use electrophoresis to determine alpha or beta
Minima
only risk is pass to offspring
Minor
cis more risk: parent can pass 2 deleted genes to offspring
trans: can only pass on one deleted gene
HbH Disease
excess beta globin but can't combine with alpha globin
binds O2 but won't release
cleared by spleen
can look a lot like iron deficiency, but never see hemolysis (high bilirubin, splenomegaly) in iron deficiency
Bart
negative coombs test, compared to erythroblastosis fetalis
Beta
mutation can result in no function or some function
minor: 1 mutated gene
major: both genes mutated
if not lead poisoning, sideroblastic, or iron, suspect thalassemia
use electrophoresis to determine alpha or beta
mediterranean thalassemia
italy/greece.,
Minor
still makes enough to be asymptomatic
increased A2 is hallmark of minor
Major
severe anemia and reduced RBC count
lots of abnormalities on smear
extra cell membrane or shrink volume
decreased volume with low Hb
bone marrow working so hard to make RBC: abnormal skull/face
crew cut: skull with fine points sticking out of it
liver/spleen make RBC with very high EPO
Intermedia
symptoms of anemia but not severe enough to require transfusion
Misc
just as likely to be infected as others, but less severe
thalassemia: genetic disorder, all RBC affected
only for mild, not major
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