A fertile male with a single sY86 deletion on the Y chromosome

Dear Editor,Y chromosome microdeletions(YCMs)occur when gene fragments are deleted from the azoospermia factor(AZF)gene that is located on chromosomal band Yql 1.YCMs are the second most common genetic cause of male infertility following Klinefelter syndrome.1 Genetic screening of AZF is widely used in the diagnosis of male infertility.YCMs are primarily identified by screening six sites as indicated in the European Academy of Andrology and the European Molecular Genetics Quality Network(EAA/EMQN)guidelines,including AZFa(sY84 and sY86),AZFb(sY127 and sY134),and AZFc(sY254 and sY255)?The AZFa region is mainly involved in spermatocyte proliferation and is considered as the most important region of AZF.2 Gene deletions in AZFa are rare.