Identification of meiotic anomalies with multiplex fluorescence in situ hybridization: Preliminary results

Objective

To characterize meiotic anomalies in infertile men by multiplex fluorescence in situ hybridization (M-FISH) and to determine whether synaptic problems affect specific bivalents or whether anomalies are random.

Design

Analysis of meiotic preparations with standard techniques and M-FISH.

Setting

Assisted reproduction centers and Universitat Autònoma de Barcelona.

Patient(s)

Three fertile men undergoing vasectomy, four sterile patients with oligoasthenoteratozoospermia, and one patient with a Robertsonian translocation t(13;14).

Intervention(s)

Unilateral testicular biopsy in controls and patients with oligoasthenoteratozoospermia and collection of a semen sample from the translocation carrier.

Main outcome measure(s)

Identification of bivalents in metaphase I and chromosomes in metaphase II and characterization of chromosome abnormalities.

Result(s)

All bivalents in metaphase I and all chromosomes in metaphase II could be identified. In controls and in one patient with oligoasthenoteratozoospermia, meiosis was normal. Other patients with oligoasthenoteratozoospermia showed different types of anomaly: desynapsis, breaks, precocious XY separation, or cryptic reorganizations. The Robertsonian translocation t(13;14) was easily identified.

Conclusion(s)

Results confirm the high incidence of synaptic errors in oligoasthenoteratozoospermia patients. Bivalents in metaphase I and chromosomes in metaphase II were individually identifiable. Nondisjunctional errors or small reorganizations overlooked in classic meiotic preparations were identified. Synaptic anomalies seem to affect meiotic bivalents at random.

Key words:  Meiosis , synaptic anomalies , chromosome reorganizations , multiplex FISH