The prevention of thalassemia

Abstract

The thalassemias are among the most common inherited diseases worldwide, affecting individuals originating from the Mediterranean area, Middle East, Transcaucasia, Central Asia, Indian subcontinent, and Southeast Asia. As the diseases require long-term care, prevention of the homozygous state constitutes a major armament in the management. This article discusses the major prevention programs that are set up in many countries in Europe, Asia, and Australia, often drawing from the experience in Sardinia. These comprehensive programs involve carrier detections, molecular diagnostics, genetic counseling, and prenatal diagnosis. Variability of clinical severity can be attributable to interactions with α-thalassemia and mutations that increase fetal productions. Special methods that are currently quite expensive and not widely applicable are preimplantation and preconception diagnosis. The recent successful studies of fetal DNA in maternal plasma may allow future prenatal diagnosis that is noninvasive for the fetus.

Figure 1.

Strategy for prevention of β-thalassemias in Mediterranean at-risk populations.

Figure 2.

Flow chart for β-thalassemia carrier screening applied in Sardinia. Thal, thalassemia; S. blot, Southern blotting.

Figure 3.

Population distribution of common β-thalassemia mutations.

Figure 4.

Decline of birth rate of thalassemia major in Sardinia.