First Report of a Chinese Family Carrying a Double Heterozygosity for Hb Q-Thailand and Hb J-Bangkok

Abstract

The double heterozygosity for α and β chain variants leads to the formation of abnormal heterodimer hybrids, which could render laboratory diagnostics in a routine setting difficult. The following is the first report of a double heterozygosity for Hb Q-Thailand [α74(EF3)Asp→His; HBA1: c.223G>C] with α⁺-thalassemia (α⁺-thal) and Hb J-Bangkok [β56(D7)Gly→Asp; HBB: c.170G>A] found in a Chinese family. Both subjects were healthy with normal or borderline hematological parameters. Hemoglobin (Hb) analyses showed a novel variant, Hb Q-Thailand and Hb J-Bangkok. Family studies helped in the initial recognition and in making presumptive diagnoses, but definitive diagnoses of these cases with complex α and β chain variants could only be obtained after DNA analysis.

Keywords:

• Capillary electrophoresis (CE)
• double heterozygous state
• Hb J-Bangkok
• Hb Q-Thailand

Disclosure statement

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

Additional information

Funding

This study was supported by Guangdong Science and Technology Department [2016A020215218].