Case report: Two cases of Hb Liuzhou-Yufeng (HBA1:c.334G>T) found in Northern Thailand

Background: Hemoglobin (Hb) Liuzhou-Yufeng is an α-globin variant caused by a heterozygous HBA1 mutation (c.334G>T). However, its clinical significance is not well-defined. Moreover, it is hard to detect using standard capillary electrophoresis (CE) or high-performance liquid chromatography (HPLC) methods and often need molecular techniques like next-generation sequencing (NGS). Objective: This study aims to describe genotype and hematological features of the first two cases with heterozygosity for Hb Liuzhou-Yufeng found in Northern Thailand and the diagnostic challenges faced. Materials and methods: Two patients with anemia, a 51-year-old female and a 32-year-old male, underwent hematological evaluation, Hb analysis using CE for case 1 and HPLC for case 2, iron studies, and red cell morphology tests. The dichlorophenolindophenol (DCIP) and osmotic fragility (OF) tests were also conducted. The molecular work-up included multiplex real-time PCR for α-thalassemia deletions, followed by NGS. Results: Both patients were confirmed by the NGS to carry Hb Liuzhou-Yufeng (ααLY/αα). Their total Hb levels were found within the ranges of mild anemia (10-12 g/dL). However, they had normocytic and normochromic red cells, and the morphology of the red blood cells appeared to be normal. In addition, the Hb analysis by HPLC and CE methods revealed normal peaks and levels of HbA, HbA2, and HbF. Conclusion: Hb Liuzhou-Yufeng seems clinically harmless but is challenging to detect using conventional methods. This study highlights the importance of NGS in finding rare Hb variants. It improves diagnostic accuracy, genetic counseling, and personalized management of hemoglobinopathy.