Thallasemia Flashcards
Define thalassemia
Genetic condition in which some of the alpha or beta genes are missing (have 4 of alpha, 2 beta
subcategories
alpha thal trait-missing 1 alpha genes-nothing else
Alpha thal zero-2 missing alpha
alpha thal HBH-3 missing
alpha thal barts (hb barts)-incompatible with life
Beta thal trait-1 missing B genes
Beta thal major-2 missing B
Beta thal intermedia-2 missing B but less severe than BTM
Aetiology and risk factors of thalassemia
heam is made of alpha and beta chains in adults-can survive with no B, but NEED alpha
If no B, foeatal chains can help (HbF)
Genetic disease-
B–heterozygous causes thal trait, and homozygous causes BTM
In BTM, nearly all heam is abnormal, but not incompatible with life
alpha- can have 1 to 4 missing depending on inheritance
the more missing, the more heam is abnormal-if all 4-cant live
risk factors:
Mediteraneans, turks, asians, Africans
Epidiemology of thalassemia
Alpha-thalassemia–unclear BUT MUCH RARER than B
in general 3 in 100 have thalassemia trait (carriers)
very strong link to meditarrean-1 in 7 greeks, 1 in 12 turks, 1 in 20 asians, 1 in 30 africans
FHx
Signs and Sx of thalassemia
B Thalassemia develops 4-6 months after birth-as B chain is used (no more Foetal)
Alpha happens immediately
B Trait-asymptomatic
a-trait-asymtp,
thal MAJOR/HbH/Intermedia-
Anemia-fatigue, pallor, sob, infections
Bone marrow hyperplasia to compensate-larger bones-jaws (large head)
abdominal distension-hepatosplenomegaly
children fail to gain weight or height
jaundice
Investigations of thalassemia
FBC-microcytic anemia
Some neutrocytosis due to bone marrow hyperplasia
Smear-microcytic, tear drop cells
target cells
Reticulocytes-higher the more affected u are
heam analysis
major: minimal to no HbA, elevated HbF and HbA2
Intermedia-less HbA, higher HbF/A2
trait-mainly HbA, raised HbF/A2
LFT-raised bilirubin elevated LDH (markers of RBC destruction)
