Comparison of the clinical application of different methods for detection of NPM1 gene mutations in leukemia / 中华检验医学杂志

ABSTRACT

Objective To analyze nucleophosmin (NPM1) gene mutations in exon 12 in patients with acute myeloid leukemia (AML) and evaluate the clinical appliance of three methods which are frequently used for detecting gene mutation. Methods Genomic DNA from bone marrow of 54 AML patients was detected by PCR for NPM1 exon 12 and screened by PCR-capillary electrophoresis, denature high-performance liquid chromatography (DHPLC) and direct sequencing separately. FLT3-ITD (FMS-like tyrosine kinease internal tandem duplication) was detected by agarose gel electrophoresis and PCR-capillary electrophoresis. Results Seven AML sample harbored NPM1 gene mutations. Five of them were the most common mutation, known as type A (an insertion of a TCTG tetranucleotide at position 960 bp). One of them was type D (an insertion of a CCTG tetranuclectide at position 960 bp). The new variant was a deletion of a TGGCAGTG sequence at 958 bp and insertion of a GCCCGCGGTTTA sequence instead. The detection ratio of the three methods was all 100% and capillary electrophoresis was more rapid, reliable and easier than the other two methods. Moreover it could detect FLT3-ITD simultaneously. The resolving power of DHPLC was affected by many factors. The direct sequencing method was tedious and the heterozygous sequence might be misread. Conclusions There is a new mutation at position 958 bp with a 12-nucleotide insertion and substitution. PCR-capillary electrophoresis is convenient to screen NPM1 mutations of AML in clinical practice.