Detection of β-globin Gene Mutations Among β-thalassaemia Carriers and Patients in Malaysia: Application of Multiplex Amplification Refractory Mutation System-Polymerase Chain Reaction

Background: β-thalassaemia is one of the most common single-gene disorders worldwide. Each ethnic population has its own common mutations, accounting for the majority of cases, with a small number of mutations for the rarer alleles. Due to the heterogeneity of β-thalassaemia and the multi-ethnicity of Malaysians, molecular diagnostics may be expensive and time consuming.

Methods: A simple polymerase chain reaction (PCR) approach involving a multiplex amplification refractory mutation system (MARMS) and one amplification refractory mutation system (ARMS), consisting of 20 β-globin gene mutations, were designed and employed to investigate β-thalassaemia patients and carriers.

Results: Out of 169 carriers tested with the MARMS, Cd 41/42 (-TTCT), Cd 26 (A-G) HbE, IVS 1-1 (G-T), and IVS 1-5 (G-C) were the most common mutations, accounting for 78.1%. Among the Malays, Cd 26 (A-G) HbE, Cd 41/42 (-TTCT), IVS 1-1 (G-T), and IVS 1-5 (G-C) were the most common mutations, accounting for 81.4%, whereas Cd 41/42 (-TTCT) and IVS 2-654 (C-T) were most common among the Chinese (79.1%).

Conclusion: We propose the use of this cheap, easy to interpret, and simple system for the molecular diagnostics of β-thalassaemia among Malaysians at the Institute for Medical Research (IMR).