[Accreditation strategy for rare somatic molecular abnormalities detected or quantified by polymerase chain reaction: GBMHM recommendations].

In 2020, accreditation of molecular tests according to ISO 15189 is a requirement for all French medical laboratories. For many years, the GBMHM group (French Group of Molecular Biologists in Hematology) supports this approach through organization of external quality evaluation campaigns, and by publishing recommendations that have allowed the accreditation of the most frequent molecular tests for most laboratories. However, some molecular abnormalities concerns very few patients (and sometimes a single patient), and therefore cannot be evaluated in the same way, because of the lack of external quality controls or inter-laboratory comparisons. In order to allow the accreditation of these rare analyzes, the GBMHM proposes recommendations, based on the fact that analyzes using the same methodology than those already accredited by an extensive validation process, may be accredited without the need for full analytical validation. In particular, assays based on quantitative PCR or endpoint PCR may be accredited after verification of primer specificity, repeatability and/or reproducibility, and the determination of detection or linearity limits. These recommendations, by defining the validation approach for rare molecular abnormalities, make it possible to extend the requirement of accreditation for rare tests, to provide the best patient care.