Hemoglobin (Hb) Bart’s hydrops fetalis is a fatal condition associated with homozygous α⁰-thalassemia. Prenatal diagnosis of the disease is usually done by gap-PCR; however, misdiagnosis can occur with allelic dropout. Diagnosis using more than one method is preferred. We describe a double-check PCR assay for accurate prenatal diagnosis. The study was conducted on 64 fetuses at risk of homozygous α⁰-thalassemia encountered at our routine thalassemia diagnosis laboratory. Chorionic villus sample (CVS), amniotic fluid or fetal blood specimens were obtained from pregnant women at risk and analyzed by two PCR methods. In the first method, the SEA α⁰-thalassemia deletion of parents and fetuses were determined by gap-PCR routinely run in our laboratory. In another method, two specific fragments located 5′ to the ζ2 gene (XbaI fragment) and the α2-globin gene (RsaI fragment) together with the gap-PCR fragment were multiply co-amplified to determine the presence or absence of normal and α⁰-thalassemia alleles. The molecular diagnosis of α⁰-thalassemia was possible in all 64 fetuses using the two PCR approaches. The final diagnoses included 13 normal, 29 unaffected heterozygote and 22 homozygote α⁰-thalassemia fetuses.The two PCR assays disclosed no discordant result in the diagnosis of the Hb Bart’s hydrops fetalis caused by α⁰-thalassemia.The combined PCR assay for gap-PCR, ζ2 XbaI and α2 RsaI fragments, described here, is simple, accurate and applicable in the prenatal diagnosis of Hb Bart’s hydrops fetalis in a routine setting.

Anemia is a major public health problem in many areas of Southeast Asia. Ascertaining anemia and defining its underlying causes is essential for providing appropriate care, management, and establishment of a control program. Limited studies on these have been carried out on people living at the borders of Thailand, Lao PDR, and Cambodia. This cross-sectional study was done in four areas along the borders of Thailand, Lao PDR, and Cambodia. Blood specimens were collected from subjects aged 15–18 years in four districts including Kantharalak, Si Sa Ket province (n = 36), Nam Khun (n = 109), Nam Yuen (n = 98), and Na Chaluai (n = 128), Ubon Ratchathani province, Thailand. RBC parameters were recorded, and serum ferritin (SF) level was measured. Diagnosis of thalassemia and hemoglobinopathies was based on hemoglobin (Hb) and DNA analyses. Measurement of C-reactive protein was performed to exclude false-negative result of iron deficiency. The prevalence of anemia was found to be 25.1%. ID accounted for only 10.5%. Various types of thalassemia were identified in 67.7% of the subjects. The overall prevalence of thalassemia included 3.5% α⁰-thalassemia, 0.8% β-thalassemia, 47.7% Hb E, and 53.6% α⁺-thalassemia. The proportions of ID, thalassemia and combined ID and thalassemia among anemic subjects were 6.5%, 66.6%, and 20.4%, respectively. The results indicate that thalassemia and hemoglobinopathies rather than ID are major causes of anemia in Thailand-Lao PDR-Cambodia triangle. This information should prove useful for implementing an anemia control program in the regions.