We have developed a rapid screening protocol for deletion analysis of the complete AZFa sequence (i.e. 792 kb) on the Y chromosome of patients with idiopathic Sertoli-cell-only (SCO) syndrome. This Y deletion was mapped earlier in proximal Yq11 and first found in the Y chromosome of the SCO patient JOLAR, now designated as the AZFa reference patient. We now show that similar AZFa deletions occur with a frequency of 9% in the SCO patient group. In two multiplex polymerase chain reaction experiments, deletions of the complete AZFa sequence were identified by a typical deletion pattern of four new sequence-tagged sites (STS): AZFa-prox1, positive; AZFa-prox2, negative; AZFa-dist1, negative; AZFa-dist2, positive. The STS were established in the proximal and distal neighbourhoods of the two retroviral sequence blocks (HERV15yq1 and HERV15yq2) which encompass the break-point sites for AZFa deletions of the human Y chromosome. We have found deletions of the complete AZFa sequence always associated with a uniform SCO pattern on testicular biopsies. Patients with other testicular histologies as described in the literature and in this paper have only partial AZFa deletions. The current AZFa screening protocols can therefore be improved by analysing the extension of AZFa deletions. This may provide a valuable prognostic tool for infertility clinics performing testicular sperm extraction, as it would enable the exclusion of AZFa patients with a complete SCO syndrome.

The genes and pathways we identified are fundamental for delineating common causes of azoospermia originating in mutations affecting diverse meiotic processes and have great potential for accelerating approaches to diagnose, treat, and prevent infertility.Genet Med advance online publication 16 February 2017.

Men diagnosed as having azoospermia occasionally have a few mature sperm cells in other ejaculates. Other men may have constant, yet very low quality and quantity of sperm cells in their ejaculates, resulting in poor intracytoplasmic sperm injection (ICSI) outcome. It has not been conclusively established which source of sperm cells is preferable for ICSI when both ejaculate and testicular (fresh or frozen) sperm cells are available. It is also unclear whether there is any advantage of fresh over frozen sperm if testicular sperm is to be used. We used ejaculate, testicular (fresh or frozen) sperm cells, or both for ICSI in 13 couples. Five of these couples initially underwent ICSI by testicular sperm extraction, because the males had total azoospermia, and in later cycles with ejaculate sperm cells. Ejaculate sperm cells were initially used for ICSI in the other 8 patients, and later with testicular sperm cells. The fertilization rate was significantly higher when fresh or frozen-thawed testicular sperm cells were used than when ejaculated sperm cells were used. Likewise, the quality of the embryos from testicular (fresh and frozen) sperm was higher than from ejaculated sperm (65.3% vs 53.2%, respectively, P , .05). The use of fresh testicular sperm yielded better implantation rates than both frozen testicular sperm and ejaculate. Therefore, fresh testicular sperm should be considered first for ICSI in patients with virtual azoospermia or cryptozoospermia because of their superior fertility.

Recently, microdeletions in the azoospermic factor region of the Y chromosome, in addition to chromosomal anomalies, have been detected in men with azoospermia or severe oligozoospermia. In this study we evaluated the molecular and cytogenetic defects of infertile men. The frequency of Y microdeletions among 105 azoospermic, 28 oligozoospermic and 32 fertile men was tested on lymphocyte DNA using a series of 20 sequence-tagged sites. In addition, microdeletions were evaluated on testicular-derived DNA among 26 azoospermic patients who underwent testicular biopsy and in whom no sperm cells could be identified. Karyotype analysis was performed on 72 of the infertile patients. Deletions were detected in 6.7% azoospermic and 3.6% oligozoospermic men. No deletions were identified among the fertile men. Identical results were obtained with DNA derived either from lymphocytes or testicular tissue. The frequency of chromosomal aberrations in the 72 infertile patients tested (62 azoospermic, 10 oligozoospermic) was 16.6%, with a high percentage of gonosome anomalies. Additional andrological parameters (hormone values, cryptorchidism) failed to identify men at risk for having microdeletions before the test. Our findings support the recommendation to perform genetic defect screening among infertile men before their enrollment in an intracytoplasmic injection/in-vitro fertilization programme.