Analysis of any point mutation in DNA. The amplification refractory mutation system (ARMS)

TLDR

ARMS uses PCR primers with a mismatched 3′ residue that fail to extend, eliminating the need for restriction enzymes, allele‑specific oligos, or sequencing. ARMS enables rapid, simple, and reliable genotyping of any known mutation, accurately distinguishing heterozygotes from homozygotes and matching sequencing results in alpha‑1‑antitrypsin deficiency samples.

Abstract

We have improved the "polymerase chain reaction" (PCR) to permit rapid analysis of any known mutation in genomic DNA. We demonstrate a system, ARMS (Amplification Refractory Mutation System), that allows genotyping solely by inspection of reaction mixtures after agarose gel electrophoresis. The system is simple, reliable and non-isotopic. It will clearly distinguish heterozygotes at a locus from homozygotes for either allele. The system requires neither restriction enzyme digestion, allele-specific oligonucleotides as conventionally applied, nor the sequence analysis of PCR products. The basis of the invention is that unexpectedly, oligonucleotides with a mismatched 3'-residue will not function as primers in the PCR under appropriate conditions. We have analysed DNA from patients with alpha 1-antitrypsin (AAT) deficiency, from carriers of the disease and from normal individuals. Our findings are in complete agreement with allele assignments derived by direct sequencing of PCR products.