Antenatal screening programs are implemented in many countries and reliably detect the b-
thalassemia trait; however, they cannot exclude the a-thalassemia trait since the a genotype is not
examined. Detection of couples at risk for a child with homozygous a-thalassemia is a major aim in many
screening programs and requires accurate PCR-based genetic diagnosis and, when relevant, prenatal
diagnosis. Although available, the high cost has hindered wide-range implementation in countries in
Southeast Asia. In a study implementing molecular screening, it was found that it was not superior to
screening for microcytosis to identify individuals heterozygous for the a0-thalassemia genotype in the
ethnic groups at risk[63]; however, in populations where both b and a mutations are prevalent, avoiding
molecular techniques can result in missing the diagnosis of fetuses affected by serious a-thalassemia
syndromes. Overall, genetic screening utilizing multiplex PCR-based methods is frequently beyond the
means of countries in Southeast Asia. Financial support of major international agencies, and the