T

thalassemia A genetic disorder of the BLOODin
which the body fails to produce one or more of
the proteins necessary for the synthesis of HEMO-
GLOBIN, the protein that enables erythrocytes (red
blood cells) to carry oxygen. The consequence is
ANEMIA(inadequate oxygen to the cells through-
out the body). There are two basic types of tha-
lassemia: alpha and beta, designated according to
the responsible defunct protein chain. Within
these types are a number of subtypes. In general,
thalassemia is more common among people of
Asian and African heritage (alpha thalassemia) or
Mediterranean heritage (beta thalassemia).

Symptoms and Diagnostic Path
Mild thalassemia may produce no symptoms,
while severe thalassemia can be life-threatening.
Symptoms are generally similar for the major
forms of thalassemia and are those of anemia.
They may include

• chronic fatigue


• weakness


• HEADACHE


• Shortness of breath, especially with exertion or
  exercise


• PALPITATIONS

Severe symptoms may involve cardiovascular
crisis such as HEART ATTACK. Some forms of tha-
lassemia include excessive iron absorption by the
LIVER, HEART, and other organs, resulting in perma-
nent damage such as CIRRHOSIS, LIVER FAILURE, and
HEART FAILURE. Long-term thalassemia often results
in significant SPLENOMEGALY(enlarged SPLEEN) and
permanent changes in BONEstructure that weaken
the bones (notably with beta thalassemia). In
some people the bone changes cause pathologic or

spontaneous FRACTURE, which is the first indication

of an underlying thalassemia.

The diagnostic path includes blood tests to

measure serum iron levels, which are characteris-

tically elevated in severe thalassemia but may be

low in mild forms, and to assess hemoglobin com-

position by hemoglobin electrophoresis. BONE

MARROWbiopsy demonstrates the altered appear-

ance of developing erythrocytes that characterizes

thalassemia. X-rays can confirm changes to the

structure of the bones, which are most apparent in

the skull and the long bones of the arms and legs.

Treatment Options and Outlook

People who have symptoms as a result of their

thalassemia require lifelong BLOOD TRANSFUSION,

with either whole blood or packed red cells (ery-

throcytes), typically every two or three weeks.

These transfusions provide normal erythrocytes

that can transport oxygen through the blood-

stream, with transfusions timed at intervals that

approximate the body’s normal process of new

ERYTHROCYTErelease and old erythrocyte cleansing.

However, blood transfusions contribute to an esca-

lation of iron accumulation that requires treat-

ment, usually therapeutic CHELATION THERAPY

(heavy metals detoxification).

Therapeutic SPLENECTOMY (removal of the

spleen) can reduce symptoms when excessive

HEMOLYSIS (acceleration of the body’s normal

process for destroying erythrocytes) contributes to

symptoms by stimulating increased erythropoiesis

(production of new erythrocytes). BONE MARROW

TRANSPLANTATIONmay become a viable option when

other treatment approaches fail to control symp-

toms and symptoms are severe.

Thalassemia is lifelong. Most people with alpha

forms of thalassemia enjoy a good QUALITY OF LIFE,

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