Abstract

Structural hemoglobin (Hb) variant is generally caused by a point mutation in the globin gene that produces one amino acid substitution. Here, we describe a new α-chain variant found during HbA_1c measurement. HbA_1c procedures based on both ion-exchange high-performance liquid chromatography (HPLC) and capillary electrophoresis (CE) techniques failed to identify its presence. In contrast, MALDI-TOF mass spectrometry (MS) revealed the existence of a variant α-chain with a mass of 15155 Da. In addition, the Hb variant interfered with HbA_1c determined by Bio-Rad D100. DNA sequencing confirmed the occurrence of a new heterozygous mutation [HBA1:C.182A→G] at codon 60, resulting in a coding change from lysine to arginine. We named it Hb Liuzhou for thde birthplace of the patient. This case exemplified that MALDI-TOF mass spectrometry can serve as the method of choice to identify and quantify the Hb variant.

摘要

结构性血红蛋白 (Hb) 变异通常由珠蛋白基因中的点突变引起，该突变产生一个氨基酸取代。在这里，我们描述了在 HbA _1c测量过程中发现的一种新的α链变体。基于离子交换高效液相色谱 (HPLC) 和毛细管电泳 (CE) 技术的HbA _1c程序未能确定其存在。相比之下，MALDI-TOF 质谱 (MS) 显示存在质量为 15155 Da的变异α链。此外，Hb 变体干扰了 Bio-Rad D100 测定的HbA _1c。DNA测序证实了一个新的杂合突变[ HBA1:C.182A→G] 在密码子 60 处，导致编码从赖氨酸变为精氨酸。我们将其命名为 Hb 柳州，以作为患者的出生地。该案例举例说明了 MALDI-TOF 质谱法可以作为识别和量化 Hb 变体的首选方法。