The detection of rare mutations for alpha globin gene using Next Generation Sequencing

Abstract

Background Alpha thalassemia is a genetic disease caused by a mutation in the alpha globin gene. The most common mutations are large deletions, which can be routinely identified using polymerase chain reaction (PCR). Although point mutations are rare, they can be found among patients and cannot be detected by conventional PCR. Next generation sequencing (NGS) is a novel sequencing technology capable of massively parallel detecting point mutations. Objective The study aimed to detect rare mutations in alpha globin gene using NGS.  Methods  NGS analysis was performed in 8 blood samples exhibiting a rare abnormal Hb peak by Hb typing. Results A rare mutation of 8 samples are Hb G-Honolulu [HBA2:c.91G>C], Hb G-Waimanalo [HBA2:c.193G>A], Hb J-Singapore [HBA2:c.239C>G], Hb Port Phillip [HBA2:c.275T>C], Hb G-Georgia [HBA2:c.287C>T], Hb Siam [HBA1:c.46G>C], Hb Q-India [HBA1:c.193G>C] and Hb Lansing Ramathibodi [HBA1:c.264C>G]. Coinherited mutations were identified in 2 samples: Hb Lansing Ramathibodi [HBA1: c.264C>G] coinherited with alpha thalassemia (-3.7 kb) and Hb G-Waimanalo [HBA2: c.193G>A] coinherited with alpha thalassemia (-3.7 kb) and Hb E. Conclusion NGS could be used to detect rare mutations in the alpha globin gene. In addition, rare mutation samples can be used as positive controls and applied to molecular techniques in routine laboratories.