A New Hemoglobin Variant: Hb Tangshan [HBA1: c.239C > T, CD79(GCG > GTG)(Ala > Val)] Detected by MALDI-TOF MS

Abstract

In this report we decribed a new α-chain variant found during the measurement of hemoglobin A_1c (Hb A_1c) using matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry (MS). MALDI-TOF MS analysis detected an α-chain variant with a mass of 15,155 Da. However, this Hb variant was not detected during Hb A_1c measurement by cation-exchange high-performance liquid chromatography (HPLC) and capillary electrophoresis (CE) methods. Sanger sequencing validated the presence of a heterozygous missense mutation [HBA1: c.239C > T, CD79(GCG > GTG)(Ala > Val)]. The observed 28 Da mass difference exactly matches the theoretical mass difference (28 Da) resulting from the substitution of alanine (89.079) with valine (117.133). As this represents the initial documentation of the mutation, we named it Hb Tangshan after the proband’s residence.

Keywords:

• Hb Tangshan (HBA1: c.239C > T)
• MALDI-TOF MS
• Hb A_1c

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 Basic and Applied Basic Research Foundation (2023A1515010618) and Dongguan Social Development Science and Technology Program (20231800938022).