Prevalence and molecular characterization of β-thalassemia in Filipinos

Abstract

Beta-thalassemia (thal) is a common single-gene disease worldwide. However, the prevalence of beta-thal and the spectrum of beta-globin gene mutations in Filipinos remain unclear. This study sought to answer these two questions. A total of 2954 apparently healthy Filipinos in Taiwan were recruited for a prevalence study. A complete blood count was done in every subject. Those with microcytosis were studied with hemoglobin (Hb) high-performance liquid chromatography to determine the levels of Hb A2 and Hb F. Twenty-seven subjects had elevated levels of Hb A2 (>4.0%). These 27 suspected beta-thal carriers and another 16 beta-thal major patients who were being treated in the Philippines were studied to determine the spectrum of beta-globin gene mutations. Gap-PCR was used to detect the Filipino deletion of beta-thal, and direct sequencing was used to detect point or small mutations in the beta-globin gene. All of the 27 suspected beta-thal carriers had one mutation in the beta-globin gene, resulting in an overall prevalence of 0.9%. The spectrum of beta-thal mutations was similar in the carrier and patient groups. Analysis of the pooled identified seven different mutations in the study population. The Filipino deletion was the most common mutation, accounting for 45.8% (27/59) of the alleles, followed by codon 67 (-TG) (16 alleles), and Hb E (11 alleles). These three mutations accounted for 92% of the Filipino beta-thal alleles. Elucidation of the beta-thal mutations in Filipinos is useful for the genetic counseling and prenatal diagnosis of this disease.

Schistosoma japonicum Reinfection after Praziquantel Treatment Causes Anemia Associated with Inflammation

“…We found no evidence that S. japonicum-associated anemia was due to hemolysis or sequestration of erythrocytes due to splenomegaly, nor was macrocytic anemia prevalent. Clinically relevant hemoglobinopathies are likely uncommon in this study area (8,9). While there is no direct method to assess the presence of anemia associated with inflammation, the exclusion of iron deficiency and other causes of anemia, together with the associations we found between NIDA and inflammatory markers (CRP and IL-6), justifies the interpretation of NIDA as anemia associated with inflammation.…”

High Prevalence of Alpha- and Beta-Thalassemia in the Kadazandusuns in East Malaysia: Challenges in Providing Effective Health Care for an Indigenous Group

“…The deletion was also detected in 6/20 (30%) of mutant alleles in the Makasarese people from Celebes (East Indonesia) [18]. In another study of 2954 healthy Filipinos in Taiwan, the deletion was confirmed in 45.8% of the β -globin gene mutant alleles [19]. Filipino β -thalassemia deletion is not present in the Malaysian Malays and Chinese [11], and appears to be specific only to the indigenous communities in East Malaysia.…”

The effect of a school-based weekly iron supplementation delivery system among anemic schoolchildren in the Philippines

“…However, a prevalence survey of Filipinos living in Taiwan showed a 5% prevalence for a-thalassemia 1 trait, 1.7% for a-thalassemia 2 trait (Koh et al, 1998) and 4% for bthalassemia trait (Koh et al, 1999). The study participants were not screened for thalassemia, and it is thus possible that some children were carriers of the thalassemia genes.…”