Y chromosome deletions in azoospermic and severely oligozoospermic men undergoing intracytoplasmic sperm injection after testicular sperm extraction

Y chromosome deletions encompassing the AZFc region have been reported in13% of azoospermic men and 7% of severely oligozoospermic men. We examinedthe impact of these Y deletions on the severity of testicular defects in 51azoospermic men undergoing intracytoplasmic sperm injection (ICSI) aftertesticular sperm extraction (TESE) and 30 men with severe oligozoospermiaundergoing ICSI after ejaculation of spermatozoa. In addition, fiveazoospermic patients shown previously to have Y chromosome deletionsunderwent histological evaluation of their previously obtained testisbiopsy specimens. A further 27 azoospermic men underwent TESE-ICSI, but notY chromosome DNA testing. Ten of 51 azoospermic men (20%) who underwentTESE-ICSI and Y-DNA testing were found to be deleted for portions of the Ychromosome AZFc region. Of these 10, five had spermatozoa retrievable fromthe testis, and in two cases the wives became pregnant. Of the 41azoospermic men with no Y chromosome deletion, 22 (54%) had spermatozoaretrievable from the testis, and in 12 cases (29%) the wives becamepregnant. Four of 30 (13%) severely oligozoospermic patients were found tobe deleted for AZFc and in three (75%) of these pregnancy was achieved. Theother 26 severely oligozoospermic couples who had no AZFc deletionsunderwent ICSI, and 12 (46%) have an ongoing or delivered pregnancy. Theembryo implantation rate was not significantly different for azoospermic(22%), oligozoospermic (16%), Y-deleted (14%) or Y-intact (18%) men. Of thetotal of 19 infertile men who had Y chromosome deletions, 14 had deletionswithin Y chromosome intervals 6D-6F, in the AZFc region. Twelve of those 14had some spermatozoa (however few in number) in the ejaculate or testis.Five of the Y-deleted men had deletions that extended more proximally onthe Y chromosome, and in none of these could any spermatozoa be observed ineither ejaculate or testis. These results support the concept that, inazoospermic or oligozoospermic men with Y chromosome deletions limited tointervals 6D-6F (AZFc), there are generally very small numbers oftesticular or ejaculated spermatozoa. Larger Y deletions, including andextending beyond the AZFc region and encompassing more Y genes, tend to beassociated with a total absence of testicular spermatozoa. In those caseswhere spermatozoa were retrieved, the presence of Y deletions had noobvious impact on fertilization or pregnancy rate.