Microdeletion Of Exon 3 In The HBA2 Gene Associated With Mild α-Thalassemia Trait

Abstract

A mother and son presented with mild symptoms of thalassemia trait. Polymerase chain reaction (PCR) amplification of their globin genes revealed a previously unreported 203 bp microdeletion in the HBA2 gene (NG_000006.1:g.34305_34507del; HBA2:c301-30_*44del). Both mother and son were heterozygous for the deletion which included DNA coding for all of exon 3. DNA sequence analysis revealed a six nucleotide repeat (5′-CGGGCC-3′) flanking the breakpoint, suggesting that the microdeletion may have arisen as a result of reciprocal recombination within the HBA2 alleles.

• Hemoglobinopathies
• α-Globin
• Microdeletion

ACKNOWLEDGMENTS

We would like to thank Dr. K.J. Atkinson (General Practitioner, Vancouver, BC, Canada) for providing the relevant clinical details.

Declaration of Interest: This study was supported in part by a grant from the Canadian Institutes of Health Research (to RTAM). AYKW was supported by a graduate fellowship from Canadian Blood Services. The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.