Nucleophosmin is a chaperone protein that shuttles rapidly between the nucleus and the cytoplasm but predominately resides in the nucleolus. In approximately 35% of adult AML cases, mutations in exon 12 of NPM1 are detected, with over 55 mutations described to date. Mutation A, a tandem duplication of TCTG is the most prevalent accounting for 80% of mutated NPM1 cases. Pathophysiologically, exon 12 frameshift mutations result in the aberrant localisation of nucleophosmin in the cytoplasm. NPM1 mutation status is a prognostic marker in AML, especially useful in cytogenetically normal cases.
In this programme, participants are provided with lyophilised cell-lines or patient derived material for NPM1 exon 12 mutation status analysis. Participants are asked to submit a qualitative result, together with details of the methodology. Instructions for storage, reconstitution, and use of the lyophilised samples are included with the samples. Three send-outs are issued per annum, with each send-out consisting of two samples. NPM1 mutations, if present, should be expected at 'diagnostic' levels, although periodically low level 'MRD' samples may be dispatched as additional educational samples.
Pre issue testing of samples for this programme is subcontracted, although the final decision about sample suitability lies with the EQA provider; no other activities in relation to this EQA programme are subcontracted.