ISSN 2997-1036
International Journal of Hematology | Vol. 4, No. 8, August 2013 | pp. 57–64
DOI: 10.46882/2013/IJH/000044
Original Article
Title: Prevalence and molecular characteristics of Alpha-Thalassemia deletions among infants with microcytic indices
Names of Authors: S. T. Adeyemi¹, U. V. Okoye², W. X. Salami³
Authors’ Affiliations: ¹Department of Haematology and Blood Transfusion, Obafemi Awolowo University, Ile-Ife, Nigeria; ²Department of Medicine, University of Nigeria Teaching Hospital, Enugu, Nigeria; ³Department of Paediatrics, Ahmadu Bello University, Zaria, Nigeria
Abstract: Alpha-thalassemia deletions frequently cause microcytosis in infants, often mimicking or complicating nutritional iron deficiency definitions. This study investigated the prevalence and molecular characteristics of single and two-gene alpha-thalassemia deletions in 160 infants aged 6 to 24 months who presented with microcytic indices (MCV < 70 fl) and normal iron stores. Genomic DNA was extracted from peripheral blood leucocytes, followed by multiplex polymerase chain reaction analysis to detect common deletional variants (-alpha³.⁷, -alpha⁴.², --MED, and --alpha²⁰.⁵). Alpha-thalassemia variants were identified in 38.1% (61 of 160) of the microcytic infant cohort. The single-gene deletion homozygous state (-alpha³.⁷/-alpha³.⁷) was the most frequent molecular finding, occurring in 68.8% of positive cases, while the heterozygous state (-alpha³.⁷/alpha alpha) was found in 26.2%. The two-gene deletion variants (--MED) were rare, identified in only 2 infants. Infants with homozygous -alpha³.⁷ deletions showed a mean hemoglobin value of 9.4 ± 1.1 g/dl and significantly lower mean corpuscular volume values compared to heterozygous infants (58.4 fl versus 66.2 fl, P < 0.01). Multiplex polymerase chain reaction profiling is highly useful for identifying inherited hemoglobin gene deletions, helping prevent unnecessary iron supplementation in microcytic pediatric cohorts.
Keywords: Alpha-thalassemia, microcytosis, infants, polymerase chain reaction, hemoglobin deletions
Manuscript Timeline: Received: May 12, 2013; Revised: June 22, 2013; Accepted: July 10, 2013; Published: August 14, 2013