Molecular Human Reproduction, Vol. 8, No. 10, 958-963,
October 2002
© 2002 European Society of Human Reproduction and Embryology
Reproductive genetics |
Aneuploid and unbalanced sperm in two translocation carriers: evaluation of the genetic risk
1 Unitat de Biologia, Facultat de Medicina, Departament de Biologia Cel·lular, Fisiologia i d’Immunologia, Universitat Autònoma de Barcelona, 08193, Bellaterra, 2 Centro de Patología Celular, 08012, Barcelona and 3 Unitat de Biologia Cel·lular, Facultat de Ciències, Departament de Biologia Cel·lular, Fisiologia i d’Immunologia, Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain
 |
Abstract |
|---|
 Top Abstract IntroductionMaterials and methodsResultsDiscussionAcknowledgementsReferences |
|---|
Translocation carriers have an increased risk of reproductive failure or affected offspring, because of the production of unbalanced gametes by meiotic segregation or the possible presence of interchromosomal effects (ICE). We therefore performed an analysis of meiotic segregation using the human–hamster IVF technique, and an aneuploidy assay for chromosomes 6, 18, 21, X and Y, using dual and triple-colour fluorescence in-situ hybridization, in two translocation carriers, t(1;13)(q41;q22) and t(3;19)(p21;p13.3). Sperm chromosome complements were analysed by whole chromosome painting. The frequencies observed for alternate, adjacent I, adjacent II and 3:1 segregations were, for t(1;13), 41.6, 41.6, 14.5 and 2.3% respectively, and for t(3;19), the frequencies were 39.1, 35.9, 21.8 and 3.2% respectively. More than 20000 sperm per subject were analysed in the aneuploidy assay. Disomy 21 was found to be higher than other autosome disomies. Evidence for a possible ICE was found only in t(3;19). This study has shown that unbalanced sperm are more frequent than aneuploid sperm in the total sperm population. However, data in the literature suggest that the importance of each aberrant population seems to be more significant for embryo viability than would be expected from the increases in the percentages of abnormal sperm.
aneuploidy/chromosome rearrangements/FISH/genetic risk/meiotic segregation
|
Introduction |
|---|
|
TopAbstractIntroductionMaterials and methodsResultsDiscussionAcknowledgementsReferences |
|---|
Chromosome aberrations are a major cause of infertility, pregnancy loss and birth of handicapped progeny. In fact,
50% of all human reproductive failures appear to be associated with chromosome abnormalities. In human live births, the presence of a chromosome aberration is 0.5% and, of these, 0.1–0.3% correspond to structural chromosome rearrangements such as translocations, inversions, insertions and deletions (De Braekeleer and Dao, 1991
; Nielsen and Wohlert, 1991). The incidence of reciprocal translocations is 1/625 in the general population, which makes this type of reorganization the most common structural rearrangement in humans (Van Dyke et al., 1983).
During meiosis, the chromosomes of translocation carriers produce a quadrivalent configuration. The meiotic behaviour of the quadrivalent leads to the production of different proportions of balanced and unbalanced gametes; the predominant forms produced are alternate and adjacent I segregations. Since each different reciprocal translocation behaves uniquely (Rickards, 1983), the likelihood of spontaneous abortions or imbalances at term differs greatly from one translocation to another (Cohens et al., 1994). Although the theoretical risk is 50%, sperm chromosome studies in translocation carriers show that the percentages of unbalanced sperm are in the range of 20–77% (Guttenbach et al., 1997). In fact, the frequency of balanced and unbalanced forms depends upon several factors, such as the particular morphology of the chromosomes involved, the length of the interstitial and translocated segments and the number and location of chiasmata that determine the quadrivalent orientation and, consequently, the first meiotic segregation.
It has been suggested that the presence of a structural abnormality can disturb the meiotic segregation of other chromosome pairs not related to the rearrangement, thus producing aneuploid sperm. This phenomenon, known as interchromosomal effect (ICE), was first postulated for humans by Lejeune (Lejeune, 1963). Since then, some authors have reported cases of children with trisomy 21 and gonosome aneuploidies that could be related to the chromosome rearrangement detected in their fathers, specifically translocations and inversions (Aurias et al., 1978; Stoll et al., 1978; Serra et al., 1990). Recently, some groups (Vegetti et al., 2000; Pellestor et al., 2001) have observed a correlation between ICE and the abnormal semenogram found in some translocation carriers.
As a result, the individual analysis of the meiotic segregation and of the aneuploidy rate in carriers of reciprocal translocations has to be taken into consideration to evaluate the risk of pregnancy losses and unbalanced offspring, as required for genetic counselling. The purpose of our study was to estimate the contribution of unbalanced and aneuploid sperm to the genetic risk of two reciprocal translocation heterozygotes, t(1;13)(q41;q22) and t(3;19)(p21;p13.3). The use of fluorescence in-situ hybridization (FISH) on human sperm chromosomes obtained by the human sperm–hamster oocyte IVF technique shows the proportion of gametes that are chromosomally balanced or unbalanced, as well as the presence of other structural and numerical aberrations unrelated to the reorganization (Cifuentes et al., 1999). However, ICE are difficult to evaluate using the human–hamster system, because the low number of analysed cells does not allow the detection of statistically significant differences between the control group and the individual tested. During the last decade, two new techniques have been applied to detect chromosomal aneuploidies: FISH on sperm heads (Wyrobeck et al., 1994) and the primed-in-situ (PRINS) labelling technique (Pellestor et al., 1996a,b). Both analyses allow the study of thousands of sperm nuclei in a faster and simpler way, and also provide statistical power to detect any possible aneuploidy increment. In order to evaluate the possible incidence of interchromosomal effects due to the translocation, we have used FISH on sperm heads to study the aneuploidy frequencies of the sex chromosomes and chromosomes 6, 18 and 21 in these patients.
|
Materials and methods |
|---|
|
TopAbstractIntroductionMaterials and methodsResultsDiscussionAcknowledgementsReferences |
|---|
Donors
The first patient (subject 1) had a 46,XY,t(1;13)(q41;q22) karyotype. He was ascertained because of repeated reproductive failures. The patient has two brothers, both carriers of the same reorganization. Genetic studies on his parents detected the paternal origin of the translocation. The second patient (subject 2) carries a t(3;19)(p21;p13.3). He was also ascertained because of repeated reproductive failures that ended in miscarriage. Both carriers had normal spermiograms.
Each patient and the control donor provided two semen samples. Fresh ejaculates were allowed to liquefy and then aliquoted and cryopreserved. The expected quadrivalent configurations of the translocations at meiosis I are shown in Figure 1. This study was approved by the institutional ethics committee, and the patients gave written informed consent.
|
Methods
The sperm chromosome study was carried out using the human–hamster technique combined with molecular cytogenetics (FISH). Sperm chromosome complements were obtained after human capacitated sperm were coincubated with zona-free golden hamster oocytes, according to a procedure described elsewhere (Benet et al., 1991
). They were then hybridized according to our procedure (Oliver-Bonet et al., 2001). Probe mixtures containing specific whole chromosome paintings for the translocations chromosomes and centromeric probes for the sex chromosomes were used (see Table I). The slides were observed with an Olympus Ax70 photomicroscope (Olympus Optical Co., Hamburg, Germany) equipped with four simple bandpass filters for 4,6-diamidino-2-phenylindole (DAPI), fluorescein isothiocyanate (FITC), Cy3 and Aqua fluorescence, and a triple filter for DAPI/FITC/propidium iodide (PI). Chromosomes involved in the rearrangement were identified and the different segregation patterns were determined. Images were captured and produced by a Cytovision system (Applied Imaging, Sunderland, UK).
|
Samples to be used to perform the sperm nuclei assay were thawed and then washed in NaCl 0.9% to eliminate cryoprotectant. They were fixed and decondensed following a protocol previously described (Vidal et al., 1993
). Two and three-colour FISH analysis were performed in order to detect any possible interchromosomal effect (Table I
). For the two-colour FISH analysis, a centromeric probe of chromosome 6 and a locus-specific (LSI) probe for chromosome 21 were used. Three-colour FISH was performed with a combination of centromeric probes for chromosomes 18, X and Y. Following the protocol recommended by Vysis, slides were denatured for 5 min in a 70% formamide 2xstandard saline citrate solution pre-warmed at 73 ± 1°C in a waterbath, passed through ethanol series (70, 90, 100%) and air-dried. Five µl of the denatured mix-probe was applied to each slide, and an 18x18 mm coverslip was added and sealed with rubber cement. The slides were incubated overnight at 37°C. After incubation, slides were washed following the manufacturer’s instructions, dehydrated and counterstained with antifade (Vector Laboratories, Inc., Burlingame, CA, USA) containing DAPI at a concentration of 0.032 ng/ml (Sigma, Madrid, Spain). Hybridization signals were observed using an Olympus Bx60 photomicroscope (Olympus Optical Co., Hamburg, Germany), with four simple filters for visualizing DAPI, FITC, Aqua and Cy3 fluorescence and a fifth triple filter for DAPI/FITC/PI. About 10 000 sperm per slide were scored. Strict criteria were applied: only individual, well-delineated and intact sperm nuclei were evaluated, and a sperm head was scored as disomic when it displayed two clear signals for the same chromosome, which were of similar size, colour and intensity, and separated by at least one fluorescence domain. |
Results |
|---|
|
TopAbstractIntroductionMaterials and methodsResultsDiscussionAcknowledgementsReferences |
|---|
Sperm chromosomes analysis
A total of 255 sperm chromosome complements of subject 1 was analysed by FISH. The number and frequencies of the different types of segregation are listed in Table II
. Examples of segregation patterns are shown in Figure 2.
|
|
All possible 2:2 segregations were observed. Alternate and adjacent I segregations were found with identical frequencies (41.6%). Alternate segregation was present in 106 sperm chromosome complements. Within this group, 63 sperm were normal and 43 were balanced. The ratio between these two groups was not significantly different from the expected 1:1 ratio (
2-test). The number of complements bearing an adjacent I phenotype was also 106, with a similar proportion of sperm bearing a normal chromosome 1 and a derivative chromosome 13 (20.4%), and of sperm with a normal chromosome 13 and a derivative chromosome 1 (21.2%).
Adjacent II segregation was observed in 37 metaphases (14.5%), including those carrying two identical copies of a chromosome involved in the reorganization as a consequence of the existence of a crossing-over within the interstitial segment of a translocated chromosome. These complements could also be produced by non-disjunction at anaphase II, although this possibility seems less probable due to the low incidence of this event. The incidence of sperm chromosome complements displaying both a normal and a derivative chromosome 1 was 3.5%, very similar to the percentage of sperm containing the normal and the derivative chromosome 13 (3.9%). Only six metaphases (2.3%) were the result of a 3:1 segregation, displaying four of the eight possible phenotypes. The sex ratio was determined in all cells and was not different from the expected 1:1 ratio (2-test).
In subject 2, 128 sperm chromosomes were analysed by FISH. Of these, 50 were chromosomally normal or balanced, and 78 were chromosomally unbalanced (see Table II and Figure 2 for examples of segregation patterns). Among the different segregation types, alternate segregation was the most frequent (39.1%), followed by adjacent I (35.9%), adjacent II (21.8%) and 3:1 segregation (3.2%). The two possible products of alternate segregation were found with similar percentages: 18.0% of them were normal and 21.1% were balanced.
Adjacent I segregation also generates two different chromosomally unbalanced sperm products. Sperm chromosome spreads containing a normal chromosome 3 and a derivative chromosome 19 were 17.2%, quite similar to the frequency of sperm chromosome metaphases with a normal chromosome 19 and a derivative chromosome 3 (18.7%). Regarding adjacent II segregation, chromosome metaphases with a normal and a derivative chromosome 19 were more frequent than the complementary, with a normal and a derivative chromosome 3 (13.2 versus 7.8%). However, this difference was not significant (2-test). 3:1 segregation was found in four sperm complements (3.2%), representing four of the eight possible 3:1 phenotypes. The sex ratio was determined in all cells and was not different from the expected 1:1 ratio (2-test).
Aneuploidy assay
A total of 10 285 sperm in subject 1 [hybridization efficiency (HE), 99.6%], 11 171 sperm in subject 2 (HE, 99.7%) and 10 398 sperm in the control (HE, 99.4%) were analysed by triple-colour FISH. A total of 10298 sperm in subject 1 (HE 99.2%), 10227 sperm in subject 2 (HE 98.9%) and 10079 sperm in control (HE, 99.3%) were analysed by dual-colour FISH. Disomy and diploidy rates are summarized and compared with control results in Table III. Significant variations were found for disomy X (2, P = 0.0226) and for disomy XY (2, P = 0.0004) between subject 2 and the control. Interchromosomal variation of disomy rates showed statistical differences among autosomes, in both carriers and in the control. Thus, disomy for chromosome 21 (0.20% for the control, 0.21% for subject 1 and 0.23% for subject 2) were higher than disomy for chromosomes 6 and 18 (Friedman, P = 0.008).
|
|
Discussion |
|---|
|
TopAbstractIntroductionMaterials and methodsResultsDiscussionAcknowledgementsReferences |
|---|
The four different possible types of segregation were found in both reciprocal translocation carriers. The alternate phenotype is the most common segregation found in many of the translocations studied (Guttenbach et al., 1997
) and it is also the only phenotype that yields normal offspring. If an interstitial chiasma occurs, alternate phenotypes may also be generated by an adjacent I segregation, and vice versa (Armstrong and Hultén, 1998). However, the possible effect of a crossing-over on the proportions of alternate and adjacent I segregations has been overlooked, since the randomness of the phenomenon should compensate for this conversion. Therefore in our study, and as was theoretically expected, the segregation of an alternate configuration led to the production of two reciprocal kinds of gametes, normal and balanced, with frequencies that did not differ significantly from the 1:1 ratio for each carrier. To date, only three translocation carriers among the 41 studied by the human–hamster system (because FISH on sperm nuclei does not allow differentiation between normal and balanced sperm) have had more normal than balanced sperm (Burns et al., 1986; Jenderny, 1992). For subject 2, alternate segregation was the most frequent type of segregation observed and, for subject 1, alternate segregation was found with the same frequency as adjacent I segregation.
Adjacent I segregation is the most frequent origin of unbalanced gametes and it is also the most frequent segregation observed to produce unbalanced offspring (Jalbert et al., 1988). The two reciprocal types of sperm phenotypes that arise from an adjacent I configuration were found in both translocation carriers, with a frequency very similar to the expected 1:1 ratio. We did not observe any ratio distortion between sperm carrying the long translocated segment and sperm carrying the short translocated segment in either patient.
Regarding the adjacent II frequencies observed, their incidence was quite high (21.8%) in the t(3;19) carrier. Just six of the 41 translocated carriers analysed before displayed similar or higher percentages. A predisposition to adjacent II segregation has been hypothesized when the interstitial segments or the pairing regions are very short. In that case the quadrivalent configuration is a chain IV of type II because chiasmata are not formed in one or the other of the centric segments (Rickards, 1983). Recently, one group (Faraut et al., 2000) has analysed the data obtained in 31 different studies of translocation heterozygotes. Their results show an inverse relationship between the length of the centric segment and the frequency of adjacent II segregation. In this case, and according to Faraut’s analysis, the short size of the interstitial region of chromosome 19 would be responsible for the percentage observed.
Almost half of the adjacent II segregations found in the t(1;13) translocation carrier (18 of the 37 metaphases observed) displayed two copies of the same chromosome, instead of a normal chromosome and its derivative. This phenomenon was more frequent for chromosome 13 than for chromosome 1, although the difference was not significant. The presence of the two copies was due to the formation of a recombination event within the interstitial segments during pachytene. Reports on the frequency and distribution of bivalent chiasmata (Laurie and Hultén, 1985a,b) show that a second interstitial chiasmata in 13q is expected with a frequency of 81.8% given that, in these reports, they found this phenomenon in 36 of 44 bivalents analysed. On the other hand, the expected frequency for chromosome 1 is 73.6%, since they observed a second interstitial chiasmata in 39 of the 53 bivalents studied. So it seems that the differences observed between complements bearing either two copies of chromosome 13 or two derivative 13 chromosomes, and complements with two copies of chromosome 1 or of derivative 1, could reflect this slightly higher likelihood of a second chiasmata in 13q.
The carrier of t(3;19) showed an excess of sperm products with short interstitial segments [23,–3,+der(19)] over sperm products with long interstitial segments [23,–19,+der(3)] although the difference was not statistically significant (2-test). The hypothesis of unresolved chiasmata at meiosis I has been proposed (Van Hummelen et al., 1997) to explain the differences observed between reciprocal products of adjacent I and adjacent II segregations. Unresolved chiasmata would lead either to the interruption of meiosis or to the formation of partial bivalents at meiosis II and, in this case, to the segregation of whole chromosomes instead of chromatids at anaphase II. Thus, in cases of adjacent I segregation, a long translocated fragment increases the probability of an unresolved chiasma, and in cases of adjacent II, a long interstitial segment also increases this probability. Consequently, an excess of sperm products carrying the short translocated segment and sperm products with the short interstitial segments should be observed.
Jalbert et al. developed a method to predict the risk of translocation carriers producing unbalanced offspring at birth (Jalbert et al., 1980). They hypothesized that the participation of an acrocentric chromosome or of short translocated segments would tend to favour the presence of 3:1 segregation products in unbalanced newborns. It is important to distinguish between the risk at term and the segregation frequencies observed in sperm. These frequencies can be altered due to several reasons, such as zygote viability. In our study, the incidence of 3:1 segregation was low in the sperm of the two subjects, although an acrocentric chromosome and a short segment were involved in the t(1;13) and the t(3;19) respectively. However, the presence of a small chromosome in the reorganization would make the quadrivalent unstable, mainly because of a restriction or even a lack of recombination and, consequently, lead to an attachment between the small chromosome and its homologue. This situation would result in the premature separation of the small chromosome, and produce a III + I configuration. The newly formed trivalent would then proceed to a 2:1 segregation, whereas the univalent would randomly move to one or another spindle pole, leading to either 2:2 or 3:1 phenotypes (Faraut et al., 2000). Taking into account the percentage of all structural abnormal forms, the estimated risk of chromosomally unbalanced zygotes for subject 1 and subject 2 has been established at 58.4 and 60.9%, respectively. These results are slightly higher in comparison with the mean risk observed for reciprocal translocation carriers (54%) (Guttenbach et al., 1997). However, it is important to remark that the risk of fathering affected offspring would be much lower, because only viable unbalanced conceptions would reach birth.
In the past decade, the use of two- and three-colour FISH and of PRINS on decondensed sperm nuclei has allowed investigation of the frequency and distribution of aneuploidy in fertile men. The results obtained in the different reports are very heterogeneous, and extreme variations in disomy percentages can be observed among donors (Shi and Martin, 2000). These variations are mainly due to interindividual variability as well as to differences in the experimental design and in the scoring criteria applied by each observer (Egozcue et al., 1997). FISH and PRINS have also allowed the estimation of aneuploidy in translocation carriers (Shi and Martin, 2001). Recently, one group (Pellestor et al., 2001) has reported the incidence of ICE in nine rearrangement carriers as related to their semen parameters. They found evidence of ICE in translocation carriers with abnormal semenograms, but not in carriers with normal semen, who displayed normal rates of disomy and diploidy. Another study (Vegetti et al., 2000) has also suggested a correlation between poor semen parameters and an increase in aneuploidy. Additionally, these studies have shown that chromosome 21 and the sex chromosomes have a tendency to non-disjunction, both in controls and carriers. Our results show an excess of disomy 21 in the control and also in the carriers in comparison with the levels of disomy observed for other autosomes. Regarding sex-chromosome non-disjunction, only the t(3:19) carrier displayed an excess of gonosome aneuploidy. Reductions in recombination and also the location of the exchanges seem to play an important role in the genesis of these anomalies (Hassold and Hunt, 2001). A recent study (Shi et al., 2001) using single sperm typing has shown that 24,XY disomic sperm from normal donors had a highly decreased rate of recombination in the XY pseudoautosomal region, thus indicating the effect of an abnormal recombination on non-disjunction events. It is possible that due to the presence of a very short translocated fragment in the quadrivalent, a terminal exchange between homologues is not formed, and this decrease in recombination will lead to the presence of unpaired regions in the resolution of the quadrivalent into a chain configuration at metaphase I (Blanco et al., 2000). Somehow, these unpaired regions would interfere with the anaphase checkpoint, and this would have an effect, not only on the disjunction of this specific translocated chromosome, but on the segregation of other bivalents, producing different degrees of meiotic disturbance (Egozcue et al., 2000). In the case of t(3;19), the translocated segment of chromosome 19 would fail to produce a chiasma, resulting in the slight increase detected in sex chromosome disomies.
One has to bear in mind that the importance of ICE does not lie exclusively in their frequency. The consequences derived from non-disjunction are, probably, the main problem when the genetic risk is evaluated. Men who have fathered children with Down’s syndrome, Turner’s syndrome or Klinefelter’s syndrome show an increase in the aneuploidy frequency of chromosome 21 and sex chromosomes respectively (Blanco et al., 1998; Martínez-Pasarell et al., 1999; Eskenazi et al., 2002). If the chromosomes implicated produce viable aneuploidies, the risk of having affected progeny has to be carefully considered. On the other hand, if the chromosomes involved do not produce viable aneuploidies, the effect would be a reduction in the fertility of the patient, because of a decrease in the embryo viability. It can be assumed that the translocation characteristics (e.g. affected chromosomes, location of breakpoints, and asymmetry of the quadrivalent) strongly affect the incidence of ICE. However, it is worth noting that ICE are basically observed in translocation carriers with abnormal semenograms. Taking in to account that the semenogram characteristics reflect the efficiency of meiotic checkpoints, it would be of interest to investigate the relationship between the characteristics of the quadrivalent and the effectiveness of the checkpoints, to determine whether the interferences produced by the presence of a quadrivalent cause the failure of the checkpoint and how aberrant cells (such as aneuploid cells) can complete the meiotic process.
|
Acknowledgements |
|---|
|
TopAbstractIntroductionMaterials and methodsResultsDiscussionAcknowledgementsReferences |
|---|
We thank Àngels Niubó for technical assistance. We acknowledge the financial support given by FIS, 98/0031-01 and CIRIT (2001 SGR-00201). M.Oliver-Bonet is the recipient of a fellowship (AP97) from the Ministerio de Educación y Cultura.
|
Notes |
|---|
4 To whom correspondence should be addressed. E-mail: moliver{at}servet.uab.es
|
References |
|---|
|
TopAbstractIntroductionMaterials and methodsResultsDiscussionAcknowledgementsReferences |
|---|
Armstrong, S.J. and Hultén, M.A. (1998) Meiotic segregation analysis by FISH investigations in sperm and spermatocytes of translocation heterozygotes. Eur. J. Hum. Genet., 6, 430–431.[ISI][Medline]
Aurias, A., Prieur, M., Dutrillaux, B. and Lejeune, J. (1978) Systematic analysis of 95 reciprocal translocations of autosomes. Hum. Genet., 45, 259–282.[ISI][Medline]
Benet, J., Navarro, J., Genescà, A., Egozcue, J. and Templado, C. (1991) Chromosome abnormalities in human spermatozoa after albumin or TEST-yolk capacitation. Hum. Reprod., 3, 369–375.
Blanco, J., Gabau, E., Gómez, D., Baena, N., Guitart, M., Egozcue, J. and Vidal, F.(1998) Chromosome 21 disomy in the spermatozoa of the fathers of children with trisomy 21 in a population with high prevalence of Down’s syndrome. Increased incidence in cases of paternal origin. Am. J. Hum. Genet., 63, 1067–1072[ISI][Medline]
Blanco, J., Egozcue, J. and Vidal, F. (2000) Interchromosomal effects for chromosome 21 in carriers of structural chromosome reorganizations determined by fluorescence in situ hybridization on sperm nuclei. Hum. Genet., 106, 500–505.[ISI][Medline]
Burns, J.P., Koduru, P.R.K., Alonso, M.L. and Chaganti, R.S.K. (1986) Analysis of meiotic segregation in a man heterozygous for two reciprocal translocations using the hamster in vitro penetration system. Am. J. Hum. Genet., 38, 954–964.[ISI][Medline]
Cifuentes, P., Navarro, J., Blanco, J., Vidal, F., Míguez, L., Egozcue, J. and Benet, J. (1999) Cytogenetic analysis of sperm chromosomes and sperm nuclei in a male heterozygous for a reciprocal translocation t(5;7)(q21;q32) by in situ hybridisation. Eur. J. Hum. Genet., 7, 231–238.[ISI][Medline]
Cohens, O., Cans, C., Mermet, M.A., Demongeot, J. and Jalbert, P. (1994) Viability thresholds for partial trisomies and monosomies: a study of 1,159 viable unbalanced reciprocal translocations. Hum. Genet., 93, 188–194.[ISI][Medline]
De Braekeleer, M. and Dao, T.N. (1991) Cytogenetic studies in male infertility: a review. Hum. Reprod., 2, 245–250.
Egozcue, J., Blanco, J. and Vidal, F. (1997) Chromosome studies in human sperm nuclei using fluorescence in-situ hybridization (FISH). Hum. Reprod. Update, 3, 441–452.
Egozcue, S., Blanco, J., Vendrell, J.F., García, F., Veiga, A., Aran, B., Barri, P.N., Vidal, F. and Egozcue, J. (2000) Human male infertility: chromosome anomalies, meiotic disorders, abnormal spermatozoa and recurrent abortion. Hum. Reprod. Update, 6, 93–105.
Eskenazi, B., Wyrobek, A.J., Kidd, S.A., Lowe, X., Moore II, D., Weisiger, K. and Aylstock, M. (2002) Sperm aneuploidy in fathers of children with paternally and maternally inherited Klinefelter syndrome. Hum. Reprod., 17, 576–583.
Faraut, T., Mermet, M.A., Demongeot, J. and Cohen, O. (2000) Cooperation of selection and meiotic mechanisms in the production of imbalances in reciprocal translocations. Cytogenet. Cell. Genet., 88, 15–21.[ISI][Medline]
Guttenbach, M., Engel, W. and Schmid, M. (1997) Analysis of structural chromosome abnormalities in sperm of normal men and carriers of constitutional chromosomes aberrations. A review. Hum. Genet., 100, 1–21.[ISI][Medline]
Hassold, T. and Hunt, P. (2001) To err (meiotically) is human: the genesis of human aneuploidy. Nature Genet., 2, 280–291.
Jalbert, P., Sèle, B. and Jalbert, H. (1980) Reciprocal translocations: a way to predict the model of inbalanced segregation by pachytene diagram drawing. Hum. Genet., 55, 209–222.[ISI][Medline]
Jalbert, P., Jalbert, H. and Sèle, B. (1988) Types of imbalances in human reciprocal translocations: risk at birth. In Daniel, A. (ed.), The Cytogenetics of Mammalian Autosomal Rearrangements. Alan R.Liss, New York.
Jenderny, J. (1992) Sperm chromosome analysis of two males heterzygous for a t(2;17)(q35;p13) and a t(3;8)(p13;p21) reciprocal translocation. Hum. Genet., 90, 171–173.[ISI][Medline]
Laurie, D.A. and Hultén, M.A. (1985a) Further studies on bivalent chiasma frequency in human males with normal karyotypes. Ann. Hum. Genet., 49, 189–201.[ISI][Medline]
Laurie, D.A. and Hultén, M.A. (1985b) Further studies on chiasma distribution and interference in the human male. Ann. Hum. Genet., 49, 203–214.[ISI][Medline]
Lejeune, J. (1963) Autosomal disorders. Pediatrics, 32, 326–337.
Martínez-Pasarell, O., Nogués, C., Bosch, M., Egozcue, J. and Templado, C. (1999) Analysis of sex chromosome aneuploidy in sperm from fathers of Turner syndrome patients. Hum. Genet., 104, 345–349.[ISI][Medline]
Nielsen, J. and Wohlert, M. (1991) Chromosome abnormalities found among 34910 newborn children: results from a 13-year incidence study in Århus, Denmark. Hum. Genet., 87, 81–83.[ISI][Medline]
Oliver-Bonet, M., Navarro, J., Codina-Pascual, M., Carrera, M., Egozcue, J. and Benet, J. (2001) Meiotic segregation analysis in a t(4;8) carrier: comparison of FISH methods on sperm chromosome metaphases and interphase sperm nuclei. Eur. J. Hum. Genet., 9, 395–403.[ISI][Medline]
Pellestor, F., Quenesson, I., Coignet, L., Girardet, A., Andréo, B. and Charlieu, J.P. (1996a) Direct detection of disomy in human sperm by the PRINS technique. Hum. Genet., 97, 21–25.[ISI][Medline]
Pellestor, F., Girardet, A., Coignet, L., Andréo, B. and Charlieu, J.P. (1996b) Assessment of aneuploidy for chromosome, 8, 9, 13, 16, and 21 in human sperm by using primed in situ labeling technique Am. J. Hum. Genet., 58, 797–802.[ISI][Medline]
Pellestor, F., Imbert, I., Andréo, B. and Lefort, G. (2001) Study of the occurrence of interchromosomal effect in spermatozoa of chromosomal rearrangement carriers by fluorescence in-situ hybridization and primed in-situ labelling techniques. Hum. Reprod., 16, 1155–1164.
Rickards, G. (1983) Orientation behaviour of chromosome multiples interchange (reciprocal translocation) heterozygotes. Annu. Rev. Genet., 17, 443–498.[ISI][Medline]
Serra, A., Brahe, A., Millington-Ward, G., Neri, B., Tedeschi, F., Tassone, F. and Bova, R. (1990) Pericentric inversion of chromosome 9: prevalence in 300 Down syndrome families and molecular studies of nondisjunction. Am. J. Med. Genet., 7, 162–168.
Shi, Q. and Martin, R.H. (2000) Aneuploidy in human sperm: a review of the frequency and distribution of aneuploidy, effects of donor age and lifestyle factors. Cytogenet. Cell. Genet., 90, 219–226.[ISI][Medline]
Shi, Q. and Martin, R.H. (2001) Aneuploidy in human spermatozoa: FISH analysis in men with constitutional chromosomal abnormalities, and in infertile men. Reproduction, 121, 655–666.[Abstract]
Shi, Q., Spriggs, E., Leigh Field, L., Ko, E., Barclay, L. and Martin, R.H. (2001) Single sperm typing demonstrates that reduced recombination is associated with the production of aneuploid, 24, XY human sperm. Am. J. Med. Genet., 99, 34–38.[ISI][Medline]
Stoll, C., Fiori, E. and Beshara, D. (1978) Interchromosomal effect in balanced translocations. Birth Defects, 14, 393–398.
Van Dyke, D.L., Weiss, L., Roberson, J.R. and Babu, V.R. (1983) The frequency and mutation rate of balanced autosomal rearrangements in man estimated from prenatal genetic studies for advanced maternal age. Am. J. Hum. Genet., 35, 301–308.[ISI][Medline]
Van Hummelen, P., Manchester, D., Lowe, X. and Wyrobek, A.J. (1997) Meiotic segregation, recombination, and gamete aneuploidy assessed in a t(1;10)(p22.1;q22.3) reciprocal translocation carrier by three and four-probe multicolor FISH in sperm. Am. J. Hum. Genet., 61, 651–659.[ISI][Medline]
Vegetti, W., Van Assche, E., Frias, A., Verheyen, G., Bianchi, M.M., Bonduelle, M., Liebaers, I. and Van Steirteghem, A. (2000) Correlation between semen parameters and sperm aneuploidy rates investigated by fluorescence in-situ hybridization in infertile men. Hum. Reprod., 15, 351–365.
Vidal, F., Moragas, M., Català, V., Torelló, M.J., Santaló, J., Calderón, G., Jiménez, C., Barri, P.N., Egozcue, J. and Veiga, A. (1993) Sephadex filtration and human serum albumin gradients do not select spermatozoa by sex chromosome: a fluorescent in situ hybridization study. Hum. Reprod., 8, 1740–1743.
Wyrobeck, A., Robbins, W., Mehraein, Y. and Weier, H. (1994) Detection of sex chromosomal aneuploidies X–X, Y–Y in human sperm using two-chromosome fluorescence in situ hybridization. Am. J. Hum. Genet., 53, 1–7.
Submitted on March 6, 2002; accepted on July 7, 2002.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  R.H. Martin Cytogenetic determinants of male fertility Hum. Reprod. Update, June 4, 2008; (2008) dmn017v1. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. Gutierrez-Mateo, L. Gadea, J. Benet, D. Wells, S. Munne, and J. Navarro Aneuploidy 12 in a Robertsonian (13;14) carrier: Case report Hum. Reprod., May 1, 2005; 20(5): 1256 - 1260. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Anton, J. Blanco, J. Egozcue, and F. Vidal Sperm FISH studies in seven male carriers of Robertsonian translocation t(13;14)(q10;q10) Hum. Reprod., June 1, 2004; 19(6): 1345 - 1351. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||