Anping Xu1, Jian Sun2, Jie Li1, Weidong Chen1, Ruoyang Zheng1, Zhonghou Han2, Ling Ji1. 1. Department of Clinical Medical Laboratory, Peking University Shenzhen Hospital, Shenzhen, China. 2. Department of Laboratory Medicine, Qinhuangdao Maternal and Child Health Hospital, Qinhuangdao, China.
Abstract
BACKGROUND: HbA1c is the standard bio-marker for glycemic control in patients with diabetes. Here, we report a α-globin chain variant and evaluate its effect on HbA1c measurements. METHODS: A 21-year-old female was suspected of harboring a hemoglobin variant following HbA1c measurement during a routine examination using Variant II Turbo 2.0 (Bio-Rad). An oral glucose tolerance test was performed using an AU5800 clinical chemistry system (Beckman Coulter). HbA1c was reanalyzed using D10 (Bio-Rad), Capillarys 2 Flex Piercing (Sebia), and Premier Hb9210 (Trinity Biotech). Hemoglobin analysis was performed using high-performance liquid chromatography (HPLC) on the Bio-Rad Variant II (β-thalassemia short program) and capillary electrophoresis (CE, Capillarys 2 Flex Piercing, Hb program). Sanger sequencing of α and β genes was also conducted. RESULTS: HbA1c was initially measured at 24.2% using Variant II Turbo 2.0. For the oral glucose tolerance test, fasting glucose, 1-hour, and 2-hour levels were recorded as 4.25, 7.89, and 5.34 mmol/L, respectively. Subsequently, HbA1c values determined by D10, Capillarys 2 Flex Piercing (HbA1c program), and Premier Hb9210 were 4.5% (26 mmol/mol), no HbA1c value, and 4.8 (29 mmol/mol), respectively. Hemoglobin analyzed using CE and HPLC revealed an abnormal hemoglobin. Sanger sequencing identified a transversion mutation of the α2 gene [CD16(AAG>GAG), Lys>Glu, HBA2: c.49 A>G], corresponding to a Hb I variant. CONCLUSION: An unusually high HbA1c or discordance between blood sugar and HbA1c values should alert about the possibilities of hemoglobin variants.
BACKGROUND: HbA1c is the standard bio-marker for glycemic control in patients with diabetes. Here, we report a α-globin chain variant and evaluate its effect on HbA1c measurements. METHODS: A 21-year-old female was suspected of harboring a hemoglobin variant following HbA1c measurement during a routine examination using Variant II Turbo 2.0 (Bio-Rad). An oral glucose tolerance test was performed using an AU5800 clinical chemistry system (Beckman Coulter). HbA1c was reanalyzed using D10 (Bio-Rad), Capillarys 2 Flex Piercing (Sebia), and Premier Hb9210 (Trinity Biotech). Hemoglobin analysis was performed using high-performance liquid chromatography (HPLC) on the Bio-Rad Variant II (β-thalassemia short program) and capillary electrophoresis (CE, Capillarys 2 Flex Piercing, Hb program). Sanger sequencing of α and β genes was also conducted. RESULTS: HbA1c was initially measured at 24.2% using Variant II Turbo 2.0. For the oral glucose tolerance test, fasting glucose, 1-hour, and 2-hour levels were recorded as 4.25, 7.89, and 5.34 mmol/L, respectively. Subsequently, HbA1c values determined by D10, Capillarys 2 Flex Piercing (HbA1c program), and Premier Hb9210 were 4.5% (26 mmol/mol), no HbA1c value, and 4.8 (29 mmol/mol), respectively. Hemoglobin analyzed using CE and HPLC revealed an abnormal hemoglobin. Sanger sequencing identified a transversion mutation of the α2 gene [CD16(AAG>GAG), Lys>Glu, HBA2: c.49 A>G], corresponding to a Hb I variant. CONCLUSION: An unusually high HbA1c or discordance between blood sugar and HbA1c values should alert about the possibilities of hemoglobin variants.
Authors: Randie R Little; Curt L Rohlfing; Steve Hanson; Shawn Connolly; Trefor Higgins; Cas W Weykamp; Mario D'Costa; Veronica Luzzi; William E Owen; William L Roberts Journal: Clin Chem Date: 2008-06-12 Impact factor: 8.327
Authors: Curt Rohlfing; Steven Hanson; Cas Weykamp; Carla Siebelder; Trefor Higgins; Ross Molinaro; Paul M Yip; Randie R Little Journal: Clin Chim Acta Date: 2016-01-29 Impact factor: 3.786