Transcript The Profile of Beta Thalassemia In Palestine

ß Thalassemia:
an Overview
by
Abdullatif Husseini
What is thalassemia?
Thalassemia is a group of inherited
disorders of hemoglobin synthesis
characterized by a reduced or absent
output of one or more of the globin chains
of adult hemoglobin .
The name is derived from the Greek
words Thalasso = Sea" and "Hemia =
Blood" in reference to anemia of the sea.
Alpha ( ) thalassemia
It appears when a person does not
produce enough alpha chains for
hemoglobin.
It is mainly prevalent in the Africa, the
Middle East , India, and occasionally in
Mediterranean region countries.
Beta (ß) thalassemia
It appears when a person does not produce
enough beta chains for hemoglobin.
It is mainly prevalent in the Mediterranean
region countries , such as Greece, Cyprus,
Italy, Palestine and Lebanon.
Types of Thalassemia
 thalassemia: There are four types
categorized according to the severity of
their effects on persons with thalassemia.
ß thalassemia: There are 3 types
categorized according to severity:
Thalassemia minor
Thalassemia intermedia
Thalassemia major
Monogenic disorder: a single gene disorder
ß thalassemia result from over 150
Genetics
ß thalassemia
mutations of
of the
ß globin genes that result
in the absence or a reduction of the ß globin
chains
Chromosomes
Source: Thalassemia.com
Transmission of ß thalassemia
If a carrier (thalassemia minor)
marries a non-carrier, on average
half of their children will be carriers,
but none will develop thalassemia
major.
Transmission ß of thalassemia- Cont
However if two carriers marry, in
each pregnancy there is a 25%
chance of a non-carrier child, a 50%
chance of a carrier child
(thalassemia minor), and a 25%
chance of a child with thalassemia
major.
An example of inheritance:
a carrier married to a normal person
Source: Emirates Thalassemia Society
An example of inheritance- Cont:
marriage between two carriers
Source: Emirates Thalassemia Society
Types of ß thalassemia
Thalassemia Minor (Trait).
This can also be called (carrier state),
meaning that the person carries the
genetic trait for thalassemia.
Such people usually practice normal
life, but may suffer from a mild form of
anemia.
Types of ß thalassemia- Cont
Thalassemia Intermedia.
Caused by the reduced availability of
beta chains in hemoglobin and can
lead to moderate to severe anemia
and an array of complications
including bone deformities and
splenomegaly.
Types of ß thalassemia- Cont
Thalassemia Major (Cooley's Anemia).
Caused by the unavailability of beta
chains in hemoglobin leading to a very
severe and fatal if left untreated anemia.
It requires regular blood transfusions
leading to iron-overload which is treated
with chelation therapy to prevent death
from organ failure.
ß thalassemia and malaria
Thalassemic RBCs offers protection
against severe malaria caused by
Plasmodium falciparum.
The effect is associated with reduced
parasite multiplication within RBCs.
Among the contributing factors may be
the variable persistence of hemoglobin F,
which is relatively resistant to digestion
by malarial hemoglobinases.
Signs and symptoms
Thalassemia carriers (trait):
Usually no signs or symptoms are
apparent, except for a mild anemia.
Carriers are usually initially detected
through screening, or when performing
routine CBC (complete blood count).
Later it can be confirmed using
hemoglobin electrophoresis.
Signs and symptoms- Cont
Thalassemia major:
Signs such as paleness and growth
retardation, are readily detectable
since the first year of life. Those are
mainly due to severe anemia. Later
bone deformities and hepatosplenomegaly develops.
Laboratory diagnosis
Thalassemia minor:
-Blood smear shows hypochromia and
microcytosis (similar to Iron Deficiency
Anemia).
-Blood indices: MCV< 75 fl, Hb usually>
10, Hematocrit> 30%, RDW < 14%.
-Hemoglobin A2 often elevated > 3%,
sometimes reaching 7-8%.
Laboratory diagnosis- Cont
Thalassemia major:
-Blood smear shows profound
microcytic anemia, with extreme
hypochromia, tear drop, target
cells and nucleated RBCs.
-Hemoglobin may be very low at
3-4 g/dl.
Blood picture of a ß thalassemia
major patient
Source: Cooley’s Anemia Foundation
Prenatal diagnosis
Early prenatal diagnosis can be done
using first fetal blood sampling, and
later chorion villus biopsy and direct
analysis of the globin genes.
The error rate in experienced
centers is now well under 1%.
Management and treatment
Thalassemia minor (trait) :
No need for any treatment, since the
carriers are usually symptomless.
Thalassemia major:
The severe life-threatening anemia,
requires regular life long blood
transfusion, to compensate for damaged
red blood cells.
Management and treatment- Cont
Thalassemia Major:
The continuous blood transfusion will
eventually lead to iron overload, which
must be treated with chelation therapy to
avoid organ failure.
Source: Cooley’s Anemia Foundation
Management and treatment- Cont
Thalassemia Major -Continued:
Other novel treatments like bone-marrow
transplantation are very costly.
New treatments includes the use of oral
chelators, to replace the chelation treatment
using Desferal delivered by infusion under
the skin through a battery-operated pump.
Gene therapy is also an option still researched
Prevention efforts
Pre marital screening to make sure that
the couple are not both carriers.
Provision of counseling and health
education for the thalassemics, their
families and the public .
Provision of prenatal testing for
thalassemia.
Reduction of marriages between
relatives.
Thalassemia and migrants
Countries with migrants coming from
areas with high prevalence of thalassemia
such as the Mediterranean region, should
be aware of this problem.
Families with thalassemia carriers may
have increased number of cases including
thalassemia major due to intermarriages
between relatives, especially in closed
communities
Thalassemia and migrants -Cont
The following recommendations are
advised:
1- Training physicians and medical staff
on thalassemia diagnosis and treatment.
2- Provision of screening and counseling
services for those exposed.
3- Provision of appropriate health care
and management for thalassemia
patients.
Thalassemia and migrants -Cont
4- Overcoming the communication
problems, including language
barrier through utilizing translators
and nurse practitioners.
5- Community educational
programs, involving community
leaders and providing social support.
Problems commonly faced by thalassemia
major patients in developing countries
Reduced availability of blood for
transfusion.
Reduced availability of Desferal
pumps, less than third of the patients
have access to pumps.
High cost of treatment.
Problems commonly faced by thalassemia
major patients in developing countries -Cont
Limited services that blood banks
are able to give.
Unavailability of counseling services.
Lack of experience and appropriate
training among the health providers
to handle thalassemia cases.
Acknowledgement
Acknowledgement
I would Like to thank Dr. Hisham Darwish & Dr. Bashar
al-Karmi from
Thalassemia Patients’ Friends Society (TPFS)Palestine
For the valuable information they provided.
I would also like to express my sincere thanks for the
Palestinian American Research Center (PARC) for
providing me with a grant which allowed me to conduct
research at the University of Pittsburgh, where I started
preparing this lecture.