2: A-Thalasemia Flashcards
What is A Thalasemia
deletion in one of the four alleles encoding a-globin chain - cause reduced or no a-globin
In which ethnicity is a-thalassemia more common
Asian and African
how many alleles encode a globin
4
if individuals have -a/aa how will they present
Silent carrier
if individual has two deleted alleles, what is the disease called
A-Thalasemia Trait
what is a-/-a more common in
trans-mutation = African
what is aa/– more common in
cis-mutation = Asian
what is three deleted alpha alleles called
HbH Disease
what is deletion of four deleted alpha alleles called
Barts Hydrops Foetalis
how will silent carrier present
Asymptomatic
how will alpha thalasemia trait present
Mild haemolytic anaemia
how does HbH disease present
- Jaundice and anaemia at birth
- Chronic anaemia
- Hepatosplenomegaly
what is the problem with chronic haemolytic anaemia in HbH
Requires multiple transfusions - can lead to iron overload and acquired haemochromatosis
what does deletion four alleles cause
barts hydrops foetalis
what is hydrops foetalis
collection of fluid in two or more compartments
