S. Marina

Meiotic studies in a series of 1100 infertile and sterile males

SummaryMeiotic studies have been carried out in a series of 1100 infertile and sterile males. Of these, 599 cases have been studies in testicular biopsy, and 501, in semen samples. This is the largest meiotic series published so far. The incidence of meiotic anomalies was 4.3%. The most frequent chromosome abnormality was desynapsis (3.7%). However, the number of cases with a meiotic arest, usually due (73.9%) to synaptic anomalies in prophase I, was much higher (18.4%). An attempt is made to correlate the incidence of meiotic anomalies with the results of semen analysis. We discuss the prognosis of desynapsis, based on 41 cases studied, and reevaluate the results obtained in semen samples as compared with our previous results.

A new meiotic mutation: Desynapsis of individual bivalents

SummaryWe describe a new type of desynapsis observed in the semen samples and/or testicular biopsies from four subfertile patients. The desynaptic anomaly affects one or more bivalents in each cell. The incidence of this meiotic anomaly in our series of subfertile males (925 meiotic studies by May 1981) is about 0.43%.The different types of oligochiasmatic meiotic mutation described in human subfertile males are classified according to our data and those published in the literature.

Meiotic studies and synaptonemal complex analysis in two infertile males with a 13/14 balanced translocation

SummaryMeiotic and synaptonemal complex studies by light and electron microscopy have been carried out in two infertile males with a balanced 13/14 translocation. As expected, all metaphase I figures in conventional meiotic preparations contained a chain trivalent. Synaptonemal complex studies showed typical trivalent images with incomplete pairing of the acrocentric elements in the cis configuration. A review of the literature shows that the fertility of these patients is quite variable. All of them show a slightly reduced number of chiasmata (mean 46.6). Pairing in cis, as detected by electron microscopic studies, does not seem to have a prognostic value.

Meiotic and synaptonemal complex studies in 45 subfertile males

SummaryWe describe the results of meiotic and synaptonemal complex (SC) studies in a selected series of 45 subfertile males with different meiotic and seminal alterations. SC anomalies (pairing anomalies, fragmented SCs, or presynaptic arrest) were observed in 32 cases (71.1%). In 31% of the abnormal cases, meiotic anomalies could only be detected through the study of SCs. The origin of synaptic anomalies may be related to the assembly of myosin molecules along the chromosomes. SC analysis should become routine in the study of subfertile males.

Meiotic studies in human semen

SummaryMeiotic studies can be carried out in the spermatogenic cells present in ejaculate. Using this technique, we identified one man with a reciprocal translocation and six oligochiasmatic males among 180 patients studied. The technique is easy and reliable; good-quality figures can be obtained, and meiotic studies can be carried out as often as needed.

Development and behavior of synaptonemal complexes in human spermatocytes by light and electron microscopy

SummaryWe describe in this paper the human male synaptic cycle using light and electron microscopy and the distribution of cells in the different stages of prophase I. The pattern of chromosome pairing and synapsis is an important tool to determine accurately whether a given synaptic behavior in infertile or sterile men is really abnormal or not. The relationship of prepachytene to pachytene cells is also important for the diagnosis of the different types of meiotic arrest at the primar spermatocyte level.

The decision to cancel a preimplantation genetic diagnosis cycle.

It has been suggested that a minimum number (six) of cumulus‐oocyte complexes (COCs) should be retrieved for fertilization to offer enough chances to ensure a pregnancy after a preimplantation genetic diagnosis (PGD) procedure. Therefore a decision to cancel a PGD cycle should be adequately weighted to offer the patients the highest chances to obtain a pregnancy. We describe a case where, after retrieving only three COCs suitable for fertilization, a triplet pregnancy was obtained. This case suggests that, although low numbers of COCs can reduce the effectiveness of the PGD procedure, other factors are involved in its final result. Thus, the opportunity of routinely cancelling such cycles should be reconsidered. In addition, this is, to our knowledge, the first case where sex selection was carried out to prevent the birth of carriers of the abnormal gene, and not of affected offspring. Copyright

Meiotic translocations in two sterile males

McIlree et al. (1966) carried out meiotic studies in 50 infertile or sterile males, and described the presence ofmultivalents in two oligozoospermic patients with normal unbanded somatic karyotypes. We have observed the presence of multivalents in one from 18 and six from 26 metaphase I figures in testicular biopsies from two sterile males (one with azoospermia, the other with oligoasthenozoospermia) with normal 46,XY somatic karyotypes (G and Q bands) (Figs. 1 and 2). The patients had not been irradiated or medically treated. We would be very interested to hear of similar observations from other authors.

A new synaptic anomaly: irregular synaptonemal complexes

SummaryIn this paper we describe a new synaptic anomaly characterized by the presence of irregular synaptonemal complexes (SCs) in two sterile patients.

An XX male with a 46,XX/47,XX,+Y(q12→qter) karyotype

SummaryWe describe a male with the karyotype 46,XX/47, XX,+Y(q12→qter), which may be interpreted as due to an insertion (Y;X)(Yq11→Yq12;Xp22) or to mosaicism, 46,XX/47, XX,+Y(12→qter). In any case, some of the H-Y determining genes may be located on the long arm of the Y chromosome.