Beta-thalassemia is caused by a reduced amount of the normal adult form of hemoglobin, hemoglobin A (HbA), which carries oxygen to the tissues in the body. Hemoglobin A consists of 2 types of globin chains, alpha and beta. Beta-thalassemia results when the beta-chains are non-functional or are present in reduced amounts. Beta-thalassemia can range in severity from severe anemia and hepatosplenomegaly in the first two years of life to a much milder anemia presenting later in life.
Disease frequency:
Approximately 1 in 3,600 for individuals of Mediterranean descent (mainly Greek and Italian).
Carrier frequency:
Up to 1 in 30 in individuals of Mediterranean descent (Greek and Italian mainly), approximately 1 in 30 in the general population.
Diagnosis:
Diagnosis by a physician knowledgeable about the symptoms of this disorder and by testing of the Beta-thalassemia gene.
Inheritance:
Autosomal recessive.
Carrier testing:
Available by testing of the Beta-thalassemia gene.
Prenatal diagnosis:
Genetic testing of the Beta-thalassemia gene. Available through genetic testing in couples with a previously affected child or to couples found to be at risk by carrier testing.
