Letter to the Editor Contradictory results in “Yq microdeletions in infertile men from Northern India” by Mittal et al. (Ann. Genet. 47 (2004) 331–337) To the Editor We have read with interest the paper by Mittal et al. [1] in the October–December 2004 issue of Annales de Genetique that re- ported the frequency of Y chromosome microdeletions in idio- pathic azoospermic and oligozoospermic men from Northern India. We want to comment on two technical flaws which may cast some doubts on the validity of their results. First, they described one patient that was negative for sY254, while positive for sY255. sY254 and sY255 markers are specific for the DAZ genes which are present in four copies [2]. The absence of both STSs indicates deletion of the entire AZFc region, which removes all copies of the DAZ genes. According to guidelines endorsed by the European Academy of Andrology (EAA) and the European Molecular Genetics Quality Network (EMQN), the dele- tion of only one of these two STS is impossible and should be always regarded as a methodological error [3]. Second, they described two patients that were negative for sY254, sY255 and sY124 (AZFb), while positive for sY133 (AZFb) and sY128 (AZFb). AZFbc microdeletions occur by to two major mechanisms involving homologous recombination between P5/distal P1 or between P4/distal P1 [4]. According to the MSY (male-specific region of the Y chromosome) reference sequence [5], sY124 is in the median while the sY128 and sY133 are in the distal part of AZFb. Therefore, presence of sY128 and sY133 in the AZFbc patients are impossible and should be considered as a methodological error. References [1] R.D. Mittal, G. Singh, A. Srivastava, M. Pradhan, A. Kesari, A. Makker, B. Mittal, Y chromosome micro-deletions in idiopathic infertility from Northern India, Ann. Genet. 47 (2004) 331–337. [2] R. Saxena, J.W. de Vries, S. Repping, R.K. Alagappan, H. Skaletsky, L.G. Brown, et al., Four DAZ genes in two clusters found in the AZFc region of the human Y chromosome, Genomics 67 (2000) 256–267. [3] M. Simoni, E. Bakker, C. Krausz, EAA/EMQN best practice guidelines for molec- ular diagnosis of y-chromosomal microdeletions. State of the art 2004, Int. J. Androl. 27 (2004) 240–249. [4] S. Repping, H. Skaletsky, J. Lange, S. Silber, F. Van der Veen, R.D. Oates, et al., Recombination between palindromes P5 and P1 on the human Y chromosome causes massive deletions and spermatogenic failure, Am. J. Hum. Genet. 71 (2002) 906–922. [5] H. Skaletsky, T. Kuroda-Kawaguchi, P.J. Minx, H.S. Cordum,L. Hillier, L.G. Brown, et al., The male-specific region of the human Y chromosome is a mosaic of discrete sequence classes, Nature 423 (2003) 825–837. Kioomars Saliminejad Department of Reproductive Genetics and Biotechnology, Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran Hamid Reza Khorram Khorshid *, 1 Department of Reproductive Genetics and Biotechnology, Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran Genetic Research Center, University of Social Welfare and Rehabilitation Science, Tehran, Iran * Corresponding author. Avicenna Research Institute, Shahid Beheshti University, Evin, Tehran, Iran. PO Box: 77-19615. Tel.: þ98 21 22432020; fax: þ98 21 22432021. E-mail addresses: hrkk1@uswr.ac.ir , h.khorramkhorshid@avicenna.ac.ir (H.R. Khorram Khorshid) 18 November 2011 Available online 8 January 2012 1 Tel./fax: þ98 2122180138. Contents lists available at SciVerse ScienceDirect European Journal of Medical Genetics journal homepage: http://www.elsevier.com/locate/ejmg European Journal of Medical Genetics 55 (2012) 156 1769-7212/$ – see front matter Ó 2012 Elsevier Masson SAS. All rights reserved. doi:10.1016/j.ejmg.2011.12.007