AB024. Interpretation for Y chromosomal microdeletions of EAA/EMQN 2013 guideline

After the Klinefelter syndrome, Y chromosomal microdeletions are the second most frequent genetic cause of male infertility. The European Academy Andrology (EAA) and the European Molecular genetics Quality Network (EMQN) revised the new 2014 laboratory guidelines on Sep 2013 based on 1999 and 2004 editions according to 12 years clinical accumulation and specialist consensus. The new guideline emphasizes: (I) the Y chromosomal microdeletions region in azoospermic and severe oligozoospermic men mainly is azoospermia factor (AZF) region, include AZFa, AZFb, AZFbc, AZFc and AZFabc, only the microdeletions of relevant region have the specific clinical manifestation; (II) the guideline think the supposed AZFd region by some experts and recommended by some commercial diagnostic kits does not exist. The gr/gr deletion in AZFc region is a genetic risk factor for sperm production, but the clinical implications is not confirmed, not be recommended as the routine detection item; (III) the guideline still recommended the classical 6 sits detection, excessively high number of markers do not improve the sensitivity of the test, may even complicate the interpretation of the results, the method based on two multiplex polymerase chain reactions remains fully valid and appropriate for accurate diagnosis of AZF deletions; (IV) the performance of 12 years EQA scheme indicate that participating laboratories has demonstrated an improvement on reporting practice and decreasing diagnostic error rates by improve the performance. In Chinese infertility men, the frequency of Y chromosomal microdeletions occurrence is in high level, as 11.5%. We suggest the AZF diagnostic should be the routine detection item for azoospermic and severe oligozoospermic men, call on domestic AZF detection laboratory join the EQA scheme and complete the performance of Y chromosome microdeletions detection.