Rapid, Loop-Mediated Isothermal Amplification Detection of Celiac Disease Risk Alleles

Diagnosis of α-thalassaemia by colorimetric gap loop mediated isothermal amplification

α-Thalassaemia is an inherited haemoglobin disorder that results from the defective synthesis of α-globin protein. Couples whom both carry the α-thalassaemia 1 gene are at risk of having a foetus with the most severe thalassaemia, Hb Bart's hydrops fetalis, with a risk of maternal mortality. However, haematological parameters alone cannot distinguish between a α-thalassaemia 1 carrier and a homozygous α-thalassaemia 2, in which one α-globin gene has been deleted on each chromosome. A rapid and accurate molecular detection assay is essential for prevention of the disease in populations where α-thalassaemia 1 is common. Multiplex Gap-PCR analysis is widely used for diagnosis of α-thalassaemia. However, the technique requires a thermocycler and post-amplification processing, which limits its application in primary care or in rural areas in developing countries. Loop mediated isothermal amplification (LAMP) amplifies target DNA at a constant temperature and does not require a thermocycler. This study developed a colorimetric Gap-LAMP using malachite green to allow naked eye visualization of two deletional α-thalassaemia 1 commonly found in Asian populations, the Southeast Asian type (--^SEA) and the Thai type (--^THAI) deletions. The Gap-LAMP was performed on DNA samples from 410 individuals carrying various α-thalassaemia gene defects with 100% concordance with conventional Gap-PCR analysis. This method eliminates post-amplification processing or the use of expensive sophisticated equipment and allows screening large populations for the prevention and control of α-thalassaemia.

Loop Mediated Isothermal Amplification: A Promising Tool for Screening Genetic Mutations

Mutation screening is elemental for clinical diagnosis and in determining therapeutic strategies. Nucleic acid-based techniques are considered to be the most accurate tools in genetic diagnosis. One such technique is loop-mediated isothermal amplification (LAMP) assay, which has seen tremendous applications in recent years. The advantages of the assay lie in its rapidity, efficiency, sensitivity, and cost. It works in isothermal conditions and amplifies the target gene using DNA polymerases that have strand displacement activity. To date, the assay has been widely used in different fields of research, including pathogen detection, crop development, and disease diagnosis. However, despite the potential, its application in mutation screening has been minimal. This review highlights the LAMP assay and its variants that have been developed for screening single-nucleotide polymorphisms and gene translocations in cancer.