We characterized here for the first time the deletional HbH disease caused by a large novel α-thalassemia deletion in a 26-year-old Burmese pregnant woman. Capillary electrophoresis (CE) electropherogram revealed HbAABart's H, whereas, a single-tube multiplex real-time PCR with EvaGreen and high-resolution melting (HRM) analysis for diagnosis of three common α-thalassemia --, --, and -- deletions showed a negative result. Thus, a multiplex ligation-dependent probe amplification (MLPA) analysis was performed. The α-globin gene cluster deletion was observed spanning from upstream of to downstream of HBQ1 exon 3 covering three functional genes (, , and ). This large novel deletion has not been reported previously thus we named it α-thalassemia (--) due to its origin. In addition, deletional HbH disease is a result of compound heterozygosity for --/-α. Therefore, the characterization and identification of -- is essential for genetic counseling and preventing new cases of HbH disease and Hb Bart's hydrops fetalis.