Community-Based Screening for Heterozygous α0-Thalassemia (--SEA and --THAI Deletions) Using Multiplex Gap-PCR in Pathum Thani Province

Abstract

Introduction: Alpha-thalassemia is a significant public health problem in Thailand, particularly the Southeast Asian (--SEA) deletion and the THAI deletion (--THAI), which are major causes of heterozygous α0-thalassemia and may lead to hemoglobin Bart’s hydrops fetalis, a life-threatening condition in fetuses.

Objectives: This study aimed to determine the prevalence of heterozygous α0-thalassemia due to --SEA and --THAI deletions in a community population and to evaluate its association with hematological parameters.

Materials and Method: A cross-sectional study was conducted on 95 individuals (aged ≥18 years) residing in Pathum Thani Province. Leftover EDTA blood samples from routine health check-ups were tested for α0-thalassemia (--SEA and --THAI deletions) using multiplex gap-PCR. Hemoglobin (Hb) levels and red blood cell indices were obtained from complete blood counts. Anemia was defined by World Health Organization (WHO) criteria (Hb < 13 g/dL in males, Hb < 12 g/dL in females). Statistical analysis used Fisher’s exact test to compare proportions.

Results: Of the 95 participants, 90 (94.7%) had a normal genotype (αα/αα), and five (5.3%) were carriers of the --SEA deletion. No --THAI deletion carriers were detected. All individuals carrying the --SEA deletion exhibited anemia with microcytosis, whereas 30% of those with normal genotype were anemic. The association between --SEA carrier status and both anemia and microcytosis was statistically significant (p < 0.01).

Conclusion: The heterozygous α0-thalassemia (--SEA deletion) carrier rate was 5.3% in this community sample. Multiplex gap-PCR proved to be an effective tool for community-based thalassemia carrier screening. These findings provide essential baseline data for planning premarital screening programs and allocating resources for genetic counseling in Pathum Thani.