Rapid and highly specific screening for NPM1 mutations in acute myeloid leukemia

Abstract

NPM1 mutations, the most frequent molecular alterations in acute myeloid leukemia (AML), have become important for risk stratification and treatment decisions for patients with normal karyotype AML. Rapid screening for NPM1 mutations should be available shortly after diagnosis. Several methods for detecting NPM1 mutations have been described, most of which are technically challenging and require additional laboratory equipment. We developed and validated an assay that allows specific, rapid, and simple screening for NPM1 mutations. FAST PCR spanning exons 8 to 12 of the NPM1 gene was performed on 284 diagnostic AML samples. PCR products were visualized on a 2% agarose E-gel and verified by direct sequencing. The FAST PCR screening method showed a specificity and sensitivity of 100%, i.e., all mutated cases were detected, and none of negative cases carried mutations. The limit of detection was at 5-10% of mutant alleles. We conclude that the FAST PCR assay is a highly specific, rapid (less than 2h), and sensitive screening method for the detection of NPM1 mutations. Moreover, this method is inexpensive and can easily be integrated in the routine molecular diagnostic work-up of established risk factors in AML using standard laboratory equipment.