Rare Hemoglobin Variants: Hb G-Szuhu (HBB: c.243C>G), Hb G-Coushatta (HBB: c.68A>C) and Hb Mizuho (HBB: c.206T>C) in Sri Lankan Families

Abstract

In this short communication, we describe the clinical presentation of unusual hemoglobin (Hb), variants in three Sri Lankan cases under study for β-thalassemia intermedia (β-TI). We believe this is the first report on their occurrence in Sri Lanka as well as from the Indian subcontinent. During a molecular study performed on β-TI patients, we identified three unusual Hb variants as Hb G-Szuhu (HBB: c.243C>G), Hb G-Coushatta (HBB: c.68A>C) and Hb Mizuho (HBB: c.206T>C) in three unrelated families. Hb G-Szuhu and Hb G-Coushatta were found in combination with the common β-thalassemia (β-thal) mutation, IVS-I-5 (G>C). Both probands had mild anemia with greatly reduced red cell indices and had non palpable livers and spleens, however, by ultrasound, both were observed to be enlarged. The final Hb variant, Hb Mizuho, was identified as a heterozygous mutation found in both proband and his mother. Both family members had severe anemia and were regularly transfused and had increased red cell parameters.

• β-Thalassemia intermedia (β-TI)
• Hb G-Coushatta
• Hb G-Szuhu
• Hb Mizuho
• Sri Lanka

Acknowledgments

Our special thanks for Dr. Engin Bojnik and Dr. Stefania Gobessi, Molecular Haematology Unit, International Centre for Genetic Engineering and Biotechnology, Rome, Italy; Mr. Rexon Rudrigo and Mr. Lakshamn, Faculty of Medicine, University of Kelaniya, Kelaniya, Sri Lanka; Ms. Helena Ayub, Medical Research Council Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, Oxfordshire, UK, for their support.

Declaration of interest

This study was supported in part by National Research Council, Sri Lanka Research Grant No. NRC 09/13 and University Grant Commission, Sri Lanka Research Grant No.UGC/ICD/CRF/2009/29/1. The genetic analysis was supported by the International Centre for Genetic Engineering and Biotechnology Fellowship Award, Trieste, Italy and European Molecular Biology Organization Fellowship Award, Heidelberg, Germany. CAF and DJW are supported by the Medical Research Council, Wellcome Trust and the Anthony Cerami and Ann Dunne Foundation for World Health. The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.