Phenotypic Expression and Origin of the Rare β-Thalassemia Splice Site Mutation HBB:c.315 + 1G>T

Abstract

We present the hematological characteristics of five patients from Surinam and the bordering French Guyana, who are carriers of the rare β-thalassemia (β-thal) mutation HBB:c.315+1G>T. Analysis of the phenotype/genotype relationship shows that this allele is a β⁰-thal variant and illustrates the modulating effect of the α-globin gene status on the β-thal phenotype. The ethnic origin of the five probands, belonging to the so-called Bush Negroes Maroons of Surinam and French Guyana, strongly suggests that this β-thal mutation has a West African origin and spread in this ethnic group because of a founder effect and/or genetic drift.

Keywords:

• β-Thalassemia (β-thal)
• β-Thalassemia splice donor site mutation HBB:c.315+1G>T

ACKNOWLEDGMENTS

We thank Sandrine Lamothe (Centre Caribéen de la Drépanocytose “Guy Mérault,” Pointe-à-Pitre, Guadeloupe, France) for her excellent assistance and Dr. Rachida Boukhari (Centre Hospitalier de Cayenne, Guyane, France), for providing samples of the Guyanese patients. The Centre Caribéen de la Drépanocytose “Guy Mérault”, Pointe-à-Pitre, Guadaloupe, France and the INSERM U 763 belong to the “Centre d'Investigation Clinique” of the West Indies and French Guyana. Part of this study was supported by the Zon-Mw project nr. 21000.0105, the European Commission “ITHANET” grant nr. 026539 and by the “CPER/Région Guadeloupe” and INSERM, grant nr. J-2-1-J210002.

Declaration of Interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.