Internal Medicine

0521779407-20 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 21:22

Thalassemia 1415

■Family history of splenomegaly, splenectomy, jaundice, gallstones

■Alpha and beta thalassemia common in Mediterranean basin, South-

east Asia, southern China, India, and Africa

Signs & Symptoms

■Heterogyzotes (beta thalassemia trait or deletion of one or two alpha

globin genes) are asymptomatic.

■Clinical manifestations of beta thalassemia intermedia are variable

(mild to severe)

■Beta thalassemia not expressed clinically during first months of life

(due to presence of Hb F)

■Pallor

■Maxillary hyperplasia and frontal bossing secondary to extrame-

dullary hematopoiesis

■Short stature

■Splenomegaly

■Hepatomegaly

■Jaundice

■Congestive heart failure

■Hydrops fetalis associated with alpha thalassemia major (absence of

all four alpha globin genes). Found in Southeast Asian and Mediter-

ranean population, rare in African population.

tests

Blood

■Alpha thalassemia silent carrier: normal

■microcytic, hypochromic anemia (normal to mild with alpha or beta

thalassemia trait), target cells, variable basophilic stippling

■Hb H (beta 4 ) inclusion bodies can be stained with brilliant cresyl

blue and may be seen with alpha thalassemia

■elevated red cell count

■increased indirect bilirubin

■hemoglobin electrophoresis:

➣beta thalassemia: elevated Hb A 2. Note: normal Hb A 2 does not

rule out beta thalassemia (eg: delta beta thalassemia).

➣beta thalassemia major: predominance of Hb F, no Hb A

➣alpha thalassemia trait (2 alpha gene deletions): Hb Barts

(gamma 4 ) in newborn period, no increase in Hb A 2 or Hb F

➣Hb H disease (3 alpha gene deletions): 20–40% Hb Barts at birth,

5–40% Hb H by few months of life, decreased Hb A 2

➣alpha thalassemia major: Hb Barts, Hb H, Hb Portland (zeta and

epsilon chains), no HbF or Hb A.