Detection of a Hb A 2 -Melbourne (HBD: c.130G>A) combined with β-thalassemia in a Chinese individual

• Published in: Journal of clinical laboratory analysis 2020-09, Vol.34 (9), p.e23401
• Main Authors: Li, Youqiong, Huang, Tongfeng, Mao, Tian, Zhang, Xiuqun, Liang, Liang, Meng, Menghui
• Format: Article
• Language: English
• Subjects: Adult; Asian People - genetics; Automation; beta-Globins - genetics; beta-Thalassemia - blood; beta-Thalassemia - diagnosis; beta-Thalassemia - genetics; Blood Cell Count; Capillary electrophoresis; China; Defects; delta-Globins - genetics; Deoxyribonucleic acid; DNA; DNA Mutational Analysis; Female; Genetic analysis; Genetic counseling; Genetic screening; Genotype & phenotype; Hematology; Hemoglobin; Hemoglobins - analysis; Hemoglobins, Abnormal - analysis; Hemoglobins, Abnormal - genetics; High-performance liquid chromatography; Humans; Medical research; Mutation; Point Mutation; Polymerase chain reaction; Population; R&D; Research & development; Thalassemia
• ISSN: 0887-8013; 1098-2825
• DOI: 10.1002/jcla.23401

Thalassemia is common in Southeast Asian countries, including China. Hb A -Melbourne is a rare hemoglobin variant and has never been reported in China. Here, we report a Hb A -Melbourne combined with β-thalassemia in Chinese individuals which is the second case described in the published reports. Complete blood counts (CBC) of a 28-year-old female showed signs of thalassemia during a routine screening. Hemoglobin analysis was subsequently performed using capillary electrophoresis (CE) and high-performance liquid chromatography (HPLC). Four common deletional α-thalassemia detection was carried out using a gap-polymerase chain reaction (PCR). PCR and reverse dot-blot were used to detect three non-deletional α-thalassemia and 17 types of point mutations in β-thalassemia. Finally, it was identified by Sanger sequencing. Her husband also had CBC, hemoglobin analysis, and genetic diagnosis. CBC of the couple showed Hb 103 and 139 g/L, mean corpuscular volume 58 and 63.1 fL, mean corpuscular hemoglobin 19.7 and 20.4 pg, respectively. Hemoglobin analysis revealed Hb X 2.4%, Hb A 2.8% by CE and Hb X 2.9%, Hb A 2.4% by HPLC in the female. The results of her husband were Hb A93.5%, Hb A2 5.7%, Hb F 0.8% by CE. Genetic analysis of both spouses detected the same CD 41/42 mutations in β-globin gene. Sanger sequencing of female identified a mutation of the δ-globin gene (HBD:c.130G>A), corresponding to Hb A -Melbourne. Hb A -Melbourne can lead to misdiagnosis of β-thalassemia. δ-globin gene mutation must be carefully examined in routine thalassemia screening.