According to the type of globin chain involved, two main types, i.e., the α- and β-thalassemias can be distinguished.In addition, complex thalassemias resulting from defective production of two to four different globin chains (δβ-, γδβ-, and εγδβ-thalassemia) are recognized (Weatherall and Clegg 2001).
Formal education on thalassemias was also introduced in the educational curriculum at the end of secondary school (Cao et al. These programs were initially directed to couples with a previous affected child (retrospective diagnosis). This finding may facilitate the carrier detection and counseling thereby contributing to the success of the program.
Although very useful for individual families, retrospective diagnosis has a limited effect on the control of homozygous β-thalassemia at the population level. In our opinion, a carrier detection procedure should be designed to avoid missing any couple at risk.
Together with sickle cell anemia, it has also been estimated that, worldwide, 9 million carriers become pregnant annually and 1.33 million pregnancies are at risk for a thalassemia major condition (Modell and Darlison 2008; Weatherall 2010b).
In the late 1970s pilot population programs directed to prevent β-thalassemia major by carrier screening, counseling, and prenatal diagnosis started in several at-risk populations in the Mediterranean area [Cyprus, Sardinia, several regions of Continental Italy (Delta Po area, Sicily), and Greece] (Angastiniotis and Hadjiminas 1981; Cao et al. At present, several countries have set up comprehensive national prevention programs, which include public awareness and education, carrier screening, and counseling, as well as information on prenatal diagnosis and preimplantation diagnosis. In most programs, carrier screening and counseling are being performed on a voluntary basis.
Because of worldwide criticism, the requirement for a certificate of premarital screening was withdrawn.
One of the obstacles for introducing prospective screening in Continental Europe is the lack of awareness among policymakers, health professionals, and groups at risk, of hemoglobin disorders and the failure to recognize that hemoglobin disorders nowadays present a significant health problem (Modell et al. In developing countries, it has been suggested that the ideal place where these preventive measures could be organized is through existing health care services.
The Genetic Aspect of Thalassemia: From Diagnosis to Treatment, Thalassemia and Other Hemolytic Anemias, Isam AL-Zwaini, Intech Open, DOI: 10.5772/intechopen.76496. The Genetic Aspect of Thalassemia: From Diagnosis to Treatment, Thalassemia and Other Hemolytic Anemias, Isam AL-Zwaini, Intech Open, DOI: 10.5772/intechopen.76496.
This chapter is distributed under the terms of the Creative Commons Attribution 3.0 License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Özgür Aldemir (November 5th 2018).
Worldwide 56,000 conceptions have a major thalassemia disorder of which approximately 30,000 are affected by β-thalassemia major and 3500 succumb perinatally from the hydrops fetalis syndrome.
Most (or many) of these patients are born in developing and low-income countries where they create an enormous health burden.