External quality assessment for mutation detection in the BRCA1 and BRCA2 genes:: EMQN's experience of 3 years

Background: The European Molecular Genetics Quality Network (EMQN) was formed in order to improve external quality assessment for molecular genetic testing in Europe. From 1999 to 2002 it received funding from the European Union under the Standards, Measurement and Testing programme (contract no. SMT4-CT98-7515). Since then, its maintenance has been supported through subscription of the participants, and it has been coordinated by the National Genetic Reference Laboratory at Manchester, UK (Rob Elles and Simon Patton; www.emqn.org). Materials and methods: Among other external quality assessment (EQA) schemes, EMQN has provided an EQA scheme for mutation detection in the breast cancer genes, BRCA1 and BRCA2, designed to cover the two important aspects of genetic testing: (i) genotyping and (ii) interpretation and reporting of results. The fourth full scheme was completed in 2003, with data evaluation pending for the 47 participants. Results: Analysis of genotyping data has pinpointed two main types of errors: (i) missing a mutation (in nine of the 17 false results a normal sequence was reported); and (ii) description of the observed sequence change by an incorrect nomenclature. Compared with the more technical process of genotyping, the writing of reports displayed a much wider variation between laboratories. Conclusions: From the reported data it is clear that external quality control should become an integral part of quality assessment in the laboratory, thus contributing to maintaining confidence in the reliability of genetic testing among patients and health professionals.