Abstract:
Thalassaemia syndromes comprise a large clinical
spectrum and a well recognized observation is the
inverse link between clinical severity and quantity of
fetal haemoglobin (HbF) present1
. It is now known
that three types of globin that produce haemoglobin
(Hb) change from e-globin (epsilone) to g-globin
(gamma) in the fetus and to b-globin (beta) around
birth. This process of change is termed “globin
switching”. Rarely, due to a genetic defect, the gglobin gene continues to function, producing gamma
chains. Therefore HbF is present throughout life
giving rise to the condition hereditary persistence of
fetal haemoglobin (HPFH)2
. Such persons are often
asymptomatic and lead normal lives. Persons with
thalassaemia major who have concomitant HPFH
have low transfusion requirements due to the
persistence of HbF, making up for the deficiency of
b-globin3
. HPFH provides a basis for a genetic
approach to cure haemoglobinapathies in the future.
