Beta-thalassemia

Last reviewed: March 2019

Last updated: November 2017

Summary

Genetic syndrome of ineffective erythropoiesis caused by mutations of the beta-globin gene.

Spectrum of severity from asymptomatic to severe anemia and skeletal changes.

Blood transfusions are required for beta-thalassemia intermedia and major, but are associated with iron overload complications.

Stem cell transplantation options offer cure.

Definition

Beta-thalassemia is an inherited microcytic anemia caused by mutation(s) of the beta-globin gene leading to decreased or absent synthesis of beta-globin, resulting in ineffective erythropoiesis. The genotypic spectrum includes homozygous and heterozygous defects, which result in a phenotypic spectrum ranging from transfusion dependence to the asymptomatic carrier state. Compound heterozygosity of beta-thalassemia with hemoglobin E mutations results in a phenotype more severe than either beta-thalassemia trait or hemoglobin E mutations alone, similar to beta-thalassemia major or intermedia.

History and exam

Key diagnostic factors

country of origin or ancestry
family history
asymptomatic

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Other diagnostic factors

lethargy
abdominal distension
failure to gain weight
low height and weight
pallor
spinal changes
large head
chipmunk facies
misaligned teeth
hepatosplenomegaly
jaundice

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Risk factors

positive family history

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Diagnostic investigations

1st investigations to order

CBC
peripheral smear
reticulocyte count
hemoglobin analysis
LFTs
plain x-rays of skull
abdominal ultrasonography
plain x-rays of long bones

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Investigations to consider

genetic testing
HLA typing

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Treatment algorithm

ONGOING