Endocrine Abstracts

Introduction: Y-chromosomal azoospermia factor (AZF) microdeletions are one of the few well-established genetic causes of male infertility, specifically azoospermia or severe oligozoospermia. Since the introduction of a PCR-based method to easily detect the distinct deletion patterns, the screening of infertile men for Y microdeletions has become a very common genetic test performed frequently by a large number of laboratories. An external quality control scheme was established in 1997 upon initiative of the Institute of Reproductive Medicine, University of Münster, Germany, shortly thereafter continued in cooperation with the European Academy of Andrology (EAA), and from 2004 onward within the framework of the European Molecular Quality Network (EMQN). Best practice guidelines describing methodology and interpretation of results are also available (Simoni et al., Int J Androl. 2004 27 240–9).

Methods: In most of the annual quality control schemes, three validated DNA samples with mock clinical case descriptions were distributed to participating labs. We retrospectively analysed the final results of each year.

Results: Between 2000 and 2010 the number of participating laboratories almost tripled from 57 to 144. The diagnostic error rate (an incorrect genotype that would lead to a misdiagnosis), decreased steeply during the first five years from almost 8% and now fluctuates at around 2%. While also variable, an assessment of the quality of diagnostic report content shows that around 50% of analyses in the last four years have scored full marks which is also an improvement on the previous early time of the scheme. Recurrent interpretation problems still arise due to laboratories using an unnecessary high number of markers, which are specifically included in commercially available kits.

Conclusions: This established external quality control scheme is a successful tool to improve the performance of participating labs and has demonstrated an improvement on reporting practice and decreasing diagnostic error rates.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.