Coinheritance of Hb A 2 -Melbourne ( HBD : c.130G>A) and Hb E ( HBB : c.79G>A) in Laos and Simultaneous High Resolution Melt Detection of Hb A 2 -Melbourne and Hb A 2 -Lampang ( HBD : c.142G>A) in a Single Tube

• Published in: Hemoglobin Vol. 43; no. 3; pp. 214 - 217
• Main Authors: Jomoui, Wittaya, Panichchob, Prapaporn, Rujirachaivej, Punchita, Panyasai, Sitthichai, Tepakhan, Wanicha
• Format: Journal Article
• Language: English
• Published: England 04.05.2019
• Subjects: Alleles; Biomarkers; DNA Mutational Analysis; Erythrocyte Indices; Female; Genotype; Hemoglobin E - genetics; Hemoglobinopathies - diagnosis; Hemoglobinopathies - genetics; Hemoglobins, Abnormal - genetics; Humans; Inheritance Patterns; Laos; Mutation; Polymerase Chain Reaction; Pregnancy; Laos; Hb A2-Melbourne; hemoglobin (Hb) variant; high resolution melt (HRM) analysis; δ-Globin gene mutation
• ISSN: 0363-0269; 1532-432X
• DOI: 10.1080/03630269.2019.1651332

We report the molecular and hematological identifications of a Hb A variant [coinheritance of Hb A -Melbourne ( : c.130G>A) and Hb E ( : c.79G>A)] found for the first time in the Lao People's Democratic Republic (PDR). The subject was a 29-year-old pregnant Laotian woman who was a foreign worker in Thailand and was diagnosed with thalassemia and hemoglobinopathies. Capillary electrophoresis (CE) demonstrated 1.6% of Hb A , with a minor unknown peak at the initial Z1 zone (1.7%). Identification of abnormal hemoglobin (Hb) using direct DNA sequencing showed a genetic defect causing a δ-globin gene missense mutation at codon 43 ( AG> AG) causing a glutamic acid to lysine substitution corresponding to Hb A -Melbourne. The origin of Hb A -Melbourne in Lao PDR may be similar to a case found in Thailand with the [+ - - - - + +] haplotype. We developed a method that could clearly detect Hb A -Melbourne and Hb A -Lampang ( : c.142G>A) mutations in a single tube using high resolution melt (HRM) analysis. The HRM analysis is a more effective method for rapid detection than conventional polymerase chain reaction (PCR), as there is no need for a post-PCR step, and no exposure to ethidium bromide. This new method would be a useful addition for the first investigation of a suspected Hb A variant in the routine molecular setting.