Philippine Journal of Science
150 (2): 495-499, April 2021
ISSN 0031 – 7683
Date Received: 22 Sep 2020

Common Alpha Globin Genes (HBA1 and HBA2)
Mutations in Filipino Patients with Alpha Thalassemia

Catherine Lynn T. Silao^1,2*, Terence Diane F. Fabella¹, Maria Liza T. Naranjo³,
Mayceemae M. Barnuevo¹, Carmencita D. Padilla^1,2, and Ernesto dJ. Yuson³†

¹Institute of Human Genetics, National Institutes of Health
²Department of Pediatrics, Philippine General Hospital
University of the Philippines, Manila 1000 Philippines
³Lung Center of the Philippines, Quezon City 1100 Philippines

*Corresponding author: ctsilao@up.edu.ph

 

ABSTRACT

Alpha (α) thalassemia results from the absence/reduced synthesis of the α-globin subunit of hemoglobin (Hb). Mutational variants in the HBA1 and HBA2, which code for α-globin, have been reported to cause varying degrees of disease severity. These variants are unique for every population. However, local data on α-globin gene mutations in Filipino α-thalassemics is currently lacking. This study aimed to identify common α-globin gene mutations in Filipino patients suspected with α-thalassemia. Two hundred sixty (260) patients suspected with α-thalassemia underwent deoxyribonucleic acid (DNA) extraction and Alpha Globin StripAssay® mutational analysis. The (–SEA/αα), (-α3.7/–SEA), (-α3.7/–FIL), (–FIL/αα), (αα/αα), (-α3.7/αα), (-α3.7/-α3.7), (-α4.2/–SEA), (–SEA/–SEA), (α2 cd 59/αα), (-α4.2/-α4.2), (-α4.2/–FIL), (–SEA/ ααCS), and (-α3.7/-α4.2) mutations were found in 30.38%, 24.62%, 20.77%, 12.31%, 6.15%, 1.54%, 1.15%, 0.77%, 0.38%, 0.38%, 0.38%, 0.38%, 0.38%, and 0.38% of the patients, respectively. These results indicate that the (–SEA/αα), (-α3.7/–SEA) and (-α3.7/–FIL) mutations are prevalent in the Filipino patients tested. The high frequencies of (–SEA, 28.46%), (-α3.7, 24.81%) and (– FIL, 16.73%) alleles in this study are important to note as these alleles may increase the risk of HbH and Hb Bart’s hydrops fetalis cases in the population