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

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.