*2.3.2.2 β–thalassemia*

Haldane has explain the very high level of β-thalassemia in some Mediterranean populations by the 'malaria hypothesis' of Haldane [117].

There is ordinarily only one copy of the HBB gene and βþ and β0 thalassemia showing the reduction and loss, respectively, of the production of functional protein. Individuals with α-thalassemia major, have profound anemia while Heterozygotes typically have mild anemia, however, symptoms can vary greatly in severity from having severe anemia to being a symptomless carrier. [118]

Generally, β-thalassemia is more of a public health problem because of this higher morbidity than α-thalassemia.

Several mechanisms have been also proposed to explain specific protection against malaria-induced


To our knowledge, no studies have investigated the risk of severe malaria in patients with β-thalassaemia.

• Increased vulnerability of the G6PD deficient erythrocyte to oxidant stress

Hemoglobinopathies are a group of IDH initially described in the subtropical regions, they are now spread all around the world. Their high frequency and clinical severity make them a global health burden mostly in Africa where there is a huge lack of resources. The measure of the yardstick of under-5 mortality has been used to assess the broad effect of hemoglobin disorders on health because most affected children can die in early childhood and most survivors can have a chronic disease. Some authors show that the disease may be cause of at least 3.4% of deaths in children aged under 5 years [135]. However, it is very difficult to estimate the burden especially as inherited disorders affect families and then communities. Worldwide, over 1% of couples are at risk for IDH most have at least one affected child. Most affected children could die in early childhood although there are now

Although the West African death rate in children aged under 5 years is 18.4%, This rate is 16.5% for children born to couples, not at risk for sickle-cell disorders, and 40% for children born to couples who are at risk [135]. Clearly, methods to assess the health burden of inherited disorders must include also a family

The burden of disease due to malaria across worldwide vary according to selected visible traits of major medical importance, including the alleles of genes encoding hemoglobin. There are several reasons for the extremely high frequency and uneven distribution of inherited hemoglobin disorders. Natural selection is by far the most important, because of the frequency of the heterozygote and the protection against malaria afforded to the homozygotes of thalassemia and HbC, followed by consanguineous marriages [9, 136]. The epidemiological transition whereby, owing to improvements of health care services, nutrition, and health positive social and behavioral factors, babies who would have probably died from the more severe hemoglobin disorders survive nowadays [39]. Then, the migration from areas of high frequency of SCD into regions like Europe and the United States

Currently, there are only limited data on the gene frequencies and the number of births of patients with common hemoglobin disorders, particularly in Africa. Micro mapping studies involving many different centers in these countries have recently found that there is remarkable diversity in the frequency of the hemoglobin disor-

For the future more micro mapping data are then needed to provide an accurate picture global burden according selective factors distribution [60]. Hemoglobinopathies are so common that they provide a convenient model for working out a genetic approach to the control of chronic childhood diseases. At present, about 250 million people (4.5% of the world population) carry a potentially pathological haemoglobinopathy gene. Haemoglobinopathy control programs, based on WHO approaches and recommendations, have been established in different countries in all WHO Regions and have been successful in the management of the problem by

Nowadays effective prevention programs have been carried out successfully in many developed countries concerning medical care for hemoglobinopathies. The programs should be extended and followed to African regions where hemoglobin

ders even over small geographical distances [137–139].

reducing the burden of the Hemoglobin Disorders [108].

• Reduced parasite replication in G6PD-deficient erythrocytes

*Inherited Disorders of Hemoglobin and* Plasmodium falciparum *Malaria*

causes its protection against parasitization

*DOI: http://dx.doi.org/10.5772/intechopen.93807*

**2.4 Global burden of the hemoglobin disorders**

better health facilities and medical care.

perspective [135].

are also cited.

**21**
