a-Thalassemia
- 1
Mutations:
b
gene:
Point
mutations
Large
deletions
a
gene:
a genes:
a1
gene:
Produces
25% of alpha globulin chains
a2
gene:
Produces
75% of alpha globulin chains
Normal
expression:
aa/aa
Types of a-thalassemia:
a+
ao
a-Thal-2
a-Thal-1
Decreased alpha chains
No alpha chains
Clinical
syndromes of a-thalassemia:
Silent
carrier
a-Thal
trait
Hb-H
disease
Hydrops
fetalis:
-a/aa
-a/-a
--/-a
--/--
--/aa