The Ratio of X- and Y-Bearing Sperm in Ejaculates of Men with Three or More Children of the Same Sex

Purpose: The present study evaluated the proportions of X-bearing and Y-bearing sperm within the semen of donors who were the declared fathers of three or more sons or daughters. Methods: The proportions of sperm were determined using dual-color fluorescence in situ hybridization to identify the X and Y chromosomes. Results: The only difference observed was in semen volume. There was no increase in the proportion of Y-bearing sperm for men with only sons (49.7 ± 1.3%) or of X-bearing sperm for men with only daughters (44.8 ± 2.6%). Conclusions: A preponderance of either sons or daughters in a family cannot be explained simply by an altered ratio of X-bearing and Y-bearing sperm in the father's semen.     

Aneuploidy rates for chromosomes X/Y and 18 among preselected spermatozoa in men with severe teratospermia

Eight infertile men with various degrees of oligoasthenoteratozoospermia and repeated implantation failure were selected for this study due to exceptionally high rates of sperm aneupoidy in their ejaculates. All subjects had normal physical examination, karyotype and serum FSH concentration. Prior to IVF treatment, spermatozoa was collected, processed, micromanipulated and tested for chromosomes X, Y and 18 using fluorescence in-situ hybridization. Aneupoidy rates for chromosomes X, Y and 18 were determined among sperm population selected for normal morphology using high-order magnification light microscopy. A second group of fast motile spermatozoa were collected using an intracytoplasmic sperm injection pipette from the medium–oil interface from microdroplets. The average aneuploidy rates for the three chromosomes were 7.6% (395/5182) in the sperm specimen before selection, 8.7% (116/1326) in the normal morphology selected group and 4.3% (59/1388; P < 0.001) in the fast motile selected group. In conclusion, high-magnification light microscopy aimed at selection of spermatozoa with normal morphology did not affect the aneuploidy rate. On the other hand, fast motile spermatozoa harboured significantly less chromosomal abnormalities (P < 0.001). Preselection of the most rapid sperm subpopulation for intracytoplasmic sperm injection may improve the qualities of the fertilizing spermatozoon.Eight infertile men with various degrees of oligoasthenoteratozoospermia and repeated implantation failure were selected for the study due to exceptionally high rates of sperm aneupoidy in their ejaculates. All subjects had normal physical examination, karyotype and serum FSH concentration. Prior to IVF treatment, spermatozoa was collected, processed, micromanipulated and tested for chromosomes X, Y and 18 using fluorescence in-situ hybridization. Aneupoidy rates for chromosomes X, Y and 18 were determined among sperm population selected for normal morphology using high-order magnification light microscopy. A second group of fast motile spermatozoa were collected using an ICSI pipette from the medium–oil interface from microdroplets. The average aneuploidy rates for the three chromosomes were 7.6% (395/5182) in the sperm specimen before selection, 8.7% (116/1326) in the normal morphology selected group and 4.3% (59/1388, P < 0.001) in the fast motile selected group. In conclusion, high-magnification light microscopy aimed at selection of spermatozoa with normal morphology did not affect the aneuploidy rate. On the other hand, the fast motile spermatozoa harboured significantly less chromosomal abnormalities. Pre-selection of the most rapid sperm subpopulation for ICSI may improve the qualities of the fertilizing spermatozoon.     

Genetics of Human Sperm

Purpose: Chromosome abnormalities in sperm were studied by fluorescence in situ hybridization to determine the frequency and distribution of abnormalities in normal men and the effect of donor age on the frequency of abnormalities. Studies of chemotherapy and infertility patients assessed any increased risk in these populations. Methods: Multicolor fluorescence in situ hybridization was performed on the sperm samples to assess aneuploidy frequencies for chromosomes 1, 2, 4, 9, 12, 13, 15, 16, 18, 20, 21, X, and Y as well as sex ratios and frequencies of diploid sperm. Results: Most chromosomes yielded disomy estimates of approximately 0.1%, whereas the frequencies for chromosome 21 and the sex chromosomes were significantly elevated. The only chromosome to show a significant paternal age effect was YY disomy. Chemotherapy patients did not have an increased risk of aneuploid sperm 2–13 years after treatment. Infertility patients had an increased risk of disomy for chromosome 1, 13, 21, and XY. Conclusions: Multicolor fluorescence in situ hybridization analysis allows comparison of sperm from various populations of men and has demonstrated that infertile patients have a significant increase in the frequency of aneuploid sperm.     

Fluorescence In Situ Hybridization with Chromosome Paint Probes: A Novel Approach To Assess Aneuploidy in Human Sperm Nuclei

Purpose: Fluorescence in situ hybridization (FISH) using whole-chromosome paint probes was performed to evaluate disomy and diploidy frequency for chromosomes 1, 18, 19, and 22 in human sperm nuclei. Methods: Ten subjects of proven fertility and normal spermatic parameters were included in the study. A dual-color FISH method was carried out. Results: A total of 157,896 spermatozoa was scored. The mean frequencies of disomic sperm for chromosomes 1, 18, 19, and 22 were 0.22% (range, 0.19 to 0.28%), 0.24% (range, 0.14 to 0.37%), 0.22% (range, 0.17 to 0.30%), and 0.25% (range, 0.21 to 0.29%), respectively. The mean frequency of diploidy was 0.14% (range, 0.09 to 0.18%). No interindividual and interchromosomal variations in the aneuploidy frequency were observed between the different subjects. Conclusions: FISH with whole-chromosome paint probes provides a novel and efficient approach for disomy assessment in human sperm nuclei.     

Implications of Sperm Chromosome Abnormalities in Recurrent Miscarriage

Purpose: Our purpose was to assess the existence of sperm chromosome abnormalities in recurrent pregnancy loss in an assisted reproduction program. Methods: In this prospective study, 12 sperm samples from couples undergoing in vitro fertilization with two or more first-trimester spontaneous abortions were analyzed. Diploidy and disomy in decondensed sperm nuclei were assessed for chromosomes 13, 18, 21, X, and Y using two- and three-color fluorescence in situ hybridization. Results: Sex chromosome disomy in sperm samples from recurrent abortion couples was significantly increased compared to that from internal controls (0.84% vs 0.37%). In a subpopulation of seven couples who underwent oocyte donation, mean frequencies for sex chromosome disomy (1%) were even higher and diploidy (0.43%) was also significantly increased. Conclusions: These results suggest an implication of sperm chromosome abnormalities in some cases of recurrent pregnancy loss.     

Sperm aneuploidy and recurrent pregnancy loss

Experiments of double target in-situ hybridization were performed separately for chromosomes 1-17, 8-18 and sex chromosomes on sperm samples from 20 couples suffering from three or more recurrent first trimester abortions. For a subset of this study population, additional experiments of multicolour fluorescence in-situ hybridization for chromosomes 4, 7, 12, 13, 15, 18, 21, and 22, were performed on the bases of the available data from abortive tissue karyotyping. A markedly high rate of sperm disomy (14.5-15.5%) was scored in only two cases. For three other patients, the cumulative disomy rates for chromosomes 1, 17, 8, 18, X and Y also increased but at a lower level (7.8-9.5%). For the remaining 15 patients, the frequency of sperm aneuploidy was moderately increased or normal. Men with recurrent pregnancy loss (RPL) and poor semen quality had baseline sperm aneuploidy and diploidy rates higher than men with normal semen parameters (with or without RPL). Using probes for chromosomes 1, 17, 8, 18, X and Y, significantly elevated frequencies of sperm aneuploidy (not diploidy) were found in 10% of men with a history of RPL. Their rate of sperm aneuploidy was 30-34%. For the other men, changes in sperm aneuploidy were not thought to affect RPL. Poor semen quality per se impacted negatively on sperm aneuploidy and diploidy, thus making the interpretation of clinical data more difficult.     

Sex chromosome aneuploidy rates in the somatic cells of infertile men

OBJECTIVE: A large number of studies have shown that the prevalence of somatic chromosome abnormalities detectable with karyotyping is higher in infertile men. However, a normal somatic karyotype does not exclude the chance of having low level mosaicism. STUDY DESIGN: Eleven men with severe oligozoospermia and 10 healthy, fertile men were included in this study. All the patients had severe oligozoospermia with sperm counts < or =3,000,000/ mL. All participants had normal physical findings and testicular volume. The probe for dual-color fluorescence in situ hybridization consisted of an alpha satellite sequence in the centromeric region of chromosome X (DXZ1) and satellite III DNA at the Yq12 region of chromosome Y (DYZ1). RESULTS: The sex chromosome aneuploidy rate was significantly higher in subjects than in controls (p<0.001). The median incidence of sex chromosome aneuploidy in the oligozoospermic group was 4.5% (range, 0.8-7.3%), while in the control group it was 0.7% (range, 0.2-1.2%)., CONCLUSION: The incidence of aneuploidy in somatic cells is significantly greater in oligozoospermic men than in normal controls. That may suggest that chromosome instability is a result of altered genetic control during mitotic cell division. Our results demonstrate that men with oligozoospermia have an elevated risk for sex chromosome abnormalities in their somatic cells.     

Separating X-Bearing Human Spermatozoa Through a Discontinuous Percoll Density Gradient Proved to Be Inefficient by Double-Label Fluorescent In Situ Hybridization

Purpose: Double-label fluorescence in situ hybridization (FISH) was used to evaluate the efficiency of separating X-and Y-chromosome-bearing spermatozoa through 12-step discontinuous Percoll gradients. Methods: Liquefied normal semen samples from 10 healthy donors were overlaid onto 25% Percoll and centrifuged. Parts of the sperm pellet were saved as control, while the remaining portion was separated by 12-step Percoll gradient. After centrifugation, the spermatozoa in the 80% Percoll layer were collected. The X:Y ratio of the control and separated spermatozoa was verified by double-label FISH (CEP SOX/SGYprobes) and scored blindly by one observer. Differences in the X: Y ratios between matched groups were analyzed by paired t testa. Results: The overall average labeling efficiency was 99.2%. A significant enrichment (P = 0.02) of X-bearing spermatozoa was obtained in Percoll separated fractions (mean X:Y ratio = 52.2:46.4) compared with the control group (X:Y ratio = 49.5:48.4). Discontinuous Percoll gradients also decreased the proportion of aneuploid spermatozoa (from 1.0 to 0.8%), but the differences were nonsignificant. Conclusions: Discontinuous Percoll separation did increase the X:Y ratio significantly, but the enrichment of X-bearing spermatozoa is insufficient for clinical use in preconceptional sex selection.     

HLA-G expression in trophoblast cells circulating in maternal peripheral blood during early pregnancy

OBJECTIVE: The aim of this study was to assess the use of circulating trophoblast cells in maternal peripheral blood for noninvasive prenatal diagnosis of numeric chromosomal aberrations. STUDY DESIGN: A combined procedure for immunocytochemical identification and deoxyribonucleic acid fluorescence in situ hybridization was used after a single enrichment step consisting of density gradient centrifugation. A specific HLA-G monoclonal antibody was used in combination with X and Y chromosome specific probes in deoxyribonucleic acid fluorescence in situ hybridization to confirm fetal identity of cells bearing HLA-G in the case of a male fetus. RESULTS: We detected fetal trophoblast cells expressing HLA-G in maternal blood starting at 9 weeks' gestation. In addition to fetal sex prediction with X and Y chromosome-specific probes, fetal aneuploidy was confirmed in peripheral blood from a pregnancy complicated by trisomy 21. CONCLUSION: Although the numbers of fetal cells were extremely low, the proof of concept was demonstrated. Early noninvasive prenatal screening for numeric chromosomal abnormalities with fetal trophoblast cells is feasible.     

Chromosome 15 aneuploidy in the sperm and conceptus of a sibling with variable familial expression of round-headed sperm syndrome

Objective: To characterize rates of chromosome aneuploidy in sperm from three siblings, one of whom had an IVF/ICSI conceptus with trisomy 15.

Design: Blind evaluation of the sperm chromosome aneuploidy rates, semen quality, and sperm ultrastructure.

Setting: IVF clinic and university-based andrology research laboratory.

Patient(s): Three brothers, two of whom underwent infertility evaluation and therapy.

Main Outcome Measure(s): Semen from three siblings was coded and blindly evaluated for standard World Health Organization semen quality variables and sperm ultrastructure. Sperm were decondensed and hybridized with fluorescent probes specific for chromosomes X, Y, 13, 15, 18, and 21, then evaluated microscopically to determine the aneuploidy rate for those chromosomes.

Result(s): Two siblings had increased round-headed morphology on standard morphology evaluation, which was confirmed using electron microscopy. The sperm aneuploidy rate was significantly increased for chromosome 15 in sibling 1, the father of a conceptus with trisomy 15. Aneuploidy rates were also slightly increased for chromosomes X, Y, and 18 in sibling 1.

Conclusion(s): This is the second report of increased sperm chromosome aneuploidy in infertile patients with round-headed sperm. Although ICSI is successful in treating this syndrome, the risk for aneuploidy of the conceptus may be increased. Other studies have reported an increased incidence of sperm chromosome aneuploidy in some infertile patients, but this is the first report of aneuploidy in both the sperm and conceptus of a patient undergoing IVF/ICSI.     

Rapid prenatal diagnosis by fluorescent in situ hybridization of chorionic villi: an adjunct to long-term culture and karyotype.

OBJECTIVE: This series was designed to assess in a pilot study the feasibility of using fluorescence in situ hybridization on chorionic villi. STUDY DESIGN: We constructed probes derived from specific subregions of human chromosomes 21, 18, 13, X, and Y that give a single copylike signal when used in conjunction with suppression hybridization. RESULTS: In a blind series of 47 samples all, including one trisomy 21, were correctly identified. The samples were correctly classified as disomic for five chromosomes. CONCLUSIONS: The combination of chromosome-specific probe sets composed primarily of cosmid contigs and optimized hybridization and detection allowed accurate chromosome enumeration in uncultured human chorionic villi; these results are consistent with those obtained by traditional cytogenetic analysis and suggest a use for fluorescence in situ hybridization as an adjunct to karyotyping when rapid results are needed.     

A fast and efficient method for simultaneous X and Y in situ hybridization of human blastomeres

Purpose To use a 6-hr fluorescence in situ hybridization (FISH) procedure involving fluorochrome-labeled probes to determine the gender of blastomeres from arrested biopsied human embryos.Results Simultaneous detection of X and Y chromosomes was performed on 68 blastomeres with this technique. The FISH efficiency for gender determination was 95.5% (65/68). In addition, rehybridization with chromosome 8-specific probes was performed to determine the ploidy of blastomeres with more than two sex chromosomes.Conclusion This technique offers an alternative to polymerase chain reaction for the preimplantation diagnosis of X-linked diseases and can also be used for ploidy assessment.     

Analysis of aneuploidy in mini-percoll gradient centrifuged human sperm for intracytoplasmic sperm injection (ICSI) using fluorescence in situ hybridization

AIM: To study the aneuploidy rates of chromosomes 13, 18, 21, X and Y in Percoll gradient centrifuged sperm from infertile patients with male infertility factor treated by intracytoplasmic sperm injection (CSI) compared with healthy fertile donors and infertile patients with normal semen parameters. METHODS: This case-controlled study was conducted in a university hospital. Semen samples were obtained from three healthy fertile donors, eight infertile patients with normal semen parameters, and 18 infertile patients with male infertility factor. All samples were subjected to mini-Percoll gradient centrifugation before being processed through fluorescent in situ hybridization. The incidences of aneuploidy were compared using Chi-squared test. RESULTS AND CONCLUSIONS: A total of 64949 spermatozoa were analyzed. The disomy rates for chromosomes 13, 18, 21, and X or Y of sperm from patients with male infertility factor were 0.21%, 0.37%, 0.36% and 0.63%, respectively, whereas the diploidy rate was 0.17-0.23%. These incidences were higher than those from men with normal semen parameters. The result suggested that the embryos of patients with male infertility factor treated by ICSI are at increased risk of chromosome abnormalities.     

Efficient combined FISH and PRINS technique for detection of DAZ microdeletion in human sperm

Intracytoplasmic sperm injection (ICSI) now offers an effective therapeutic option for men with male infertility and is believed to allow transmission of genetically determined infertility to the male offspring. Transmission of DAZ (Deleted in Azoospermia) microdeletion is one of the major concerns for oligo and severe oligozoospermia patients. Screening of the Y chromosome microdeletion in the diagnostic work-up of infertile men is mainly done using polymerase chain reaction (PCR) on blood leukocytes. However, there are evidences showing that presence of DAZ in somatic cells might not be indicative of its presence in germ cell lineage. In this report we are going to describe a combined Primed in situ labeling (PRINS) and fluorescence in situ hybridization (FISH) technique to show the localization of DAZ gene as well as Y chromosome centromere on sperm nuclei. PRINS is a combination of FISH and in situ polymerization provides another approach for in situ chromosomal detection. In the present study the PRINS primers specific for DAZ genes and traditional direct labeled centromere FISH probes for Y and X chromosomes were used in order to simultaneously detect DAZ genes and sex chromosome aneuploidy in sperm samples.     

Simultaneous Detection of Chromosomes X, Y, 13, 18, and 21 by Fluorescence In Situ Hybridization in Blastomeres Obtained from Preimplantation Embryos

Purpose. Simultaneous fluorescence in situ hybridization (FISH) was used in a preimplantation genetic diagnosis program to determine which embryos were normal for chromosomes X, Y, 13, 18, and 21. Methods: Single blastomeres were disrupted and attached to glass slides using acetic acid and ethanol. Using a ratio mixture of chromosome enumeration DNA probes in combination with locus-specific identifier DNA probes, FISH was performed for the identification of chromosomes X, Y, 13, 18, and 21. Results: Fourteen couples enrolled in IVF produced 134 embryos for biopsy. Blastomeres subjected to five-color FISH revealed that 22% of embryos were normal for chromosomes X, Y, 13, 18, and 21. In addition, 52% were abnormal and no results could be detected for 25%. Twelve couples underwent embryo transfer, two couples did not receive embryos due to lack of any normal embryos, and three couples became pregnant. Conclusions: The simultaneous detection of five-color FISH is a feasible method to detect aneuploidy in preimplantation embryos from women of advanced maternal age.     

Chromosomal Mosaicism in Cleavage-Stage Human Embryos and the Accuracy of Single-Cell Genetic Analysis

Purpose: Our purpose was to assess the effect of chromosomal mosaicism in cleavage-stage human embryos on the accuracy of single-cell analysis for preimplantation genetic diagnosis. Methods: Multicolor fluorescence in situ hybridization with X, Y, and 7 or X, Y, 7, and 18 chromosome-specific probes was used to detect aneuploidy in cleavage-stage human embryos. Results: Most nuclei were diploid for the chromosomes tested but there was extensive mosaicism including monosomic, double-monosomic, nullisomic, chaotic, and haploid nuclei. Conclusions: Identification of sex by analysis of a single cleavage-stage nucleus is accurate but 7% of females are not identified. One or both parental chromosomes 7 were absent in at least 6.5% of the nuclei. With autosomal recessive conditions such as cystic fibrosis, carriers would be misdiagnosed as normal or affected. With autosomal dominant conditions, failure to analyze the affected parents allele (1.6–2.5%) would cause a serious misdiagnosis and analysis of at least two nuclei is necessary to reduce errors.     

Estimation of aneuploidy levels for 8, 15, 18, X and Y chromosomes in 97 human sperm samples using fluorescence in situ hybridization

Objective: To estimate the mean frequency of aneuploidy levels of chromosomes 8, 15, 18, X, and Y in human sperm, while minimizing the effect of individual factors by analyzing sperm samples from a large set of patients.

Design: Prospective randomized analysis of sperm nuclei by fluorescence in situ hybridization.

Setting: University-based laboratory for reproductive biology.

Patient(s): One hundred two patients with a large distribution of sperm parameters, randomly selected from volunteers who had presented seeking a semen analysis.

Intervention(s): The sperm samples were prepared for fluorescence in situ hybridization.

Main Outcome Measure(s): The disomy frequencies for chromosomes 8, 15, 18, and sex chromosomes were determined using fluorescence in situ hybridization.

Result(s): The mean frequencies of disomy for autosomes were 0.18% for chromosome 8, 0.06% for chromosome 15, 0.2% for chromosome 18, and 0.24% for gonosomes (XX, 0.04%; YY, 0.05%; XY, 0.15%).

Conclusion(s): This study confirms other previous evaluations on restricted numbers of patients. Our results seem to confirm a relative equiprobability of disomy frequencies concerning the different chromosomal pairs during male meiosis.     

Comparative genomic hybridization for cytogenetic evaluation of stillbirth

OBJECTIVE: To ascertain the feasibility and reliability of comparative genomic hybridization for cytogenetic evaluation of macerated stillbirths. MATERIALS: We examined ten stillborn fetuses above 15 weeks' gestation whose karyotypes were unknown because of tissue culture failure. Sixteen fetuses that were successfully karyotyped using prenatal or postnatal tissues were also examined as controls, including five pregnancy terminations with autosomal aneuploidy, one with sex chromosome aneuploidy, one with a chromosomal deletion; five macerated fetuses with normal karyotypes, three with autosomal aneuploidy, and one with sex chromosome aneuploidy and discrepancy between chorionic villi and fetus. RESULTS: All comparative genomic hybridization analyses in fresh and macerated tissues were successful except for one. All normal karyotypes and aneuploidies were confirmed. Comparative genomic hybridization failed in one fetus with a deletion of the short arm of chromosome 18. In the stillborn fetuses without known karyotypes, one aberrant profile was found; however, the results were not confirmed with interphase fluorescence in situ hybridization. In one fetus triploidy was diagnosed with DNA flow cytometry. CONCLUSION: Comparative genomic hybridization is a valuable backup technique for aneuploidy screening in tissues from macerated stillborn fetuses when tissue culture fails. Gains or losses can subsequently be confirmed by fluorescence in situ hybridization, using DNA probes that focus on specific loci of a chromosome.     

Incidence of sperm aneuploidy in relation to semen characteristics and assisted reproductive outcome.

OBJECTIVE: To evaluate the incidence of sperm aneuploidy in men screened for infertility and identify any eventual relation with assisted reproductive outcome. DESIGN: Controlled prospective study. SETTING: University hospital-based IVF program. PATIENT(S): Infertile couples who were screened for sperm aneuploidy and evaluated for IVF treatment. INTERVENTION(S): Fluorescence in situ hybridization was used to identify chromosomes 18, 21, X, and Y. The assisted reproductive techniques of IVF and intracytoplasmic sperm injection were used for infertility treatment. MAIN OUTCOME MEASURE(S): The incidence of sperm aneuploidy, semen parameters, fertilization rate, pregnancy characteristics, and rate of neonatal malformations were determined. RESULT(S): Oligozoospermic and teratozoospermic men had a significantly higher incidence of chromosomal abnormalities than men with normal semen parameters (2.7% vs. 1.8%). The increased frequency of sperm aneuploidy did not appear to affect pregnancy losses or the occurrence of neonatal malformations. CONCLUSION(S): Suboptimal semen samples had a higher incidence of aneuploidy. In this study, the increased frequency of chromosomal abnormalities did not have a direct effect on the fertilization rate, pregnancy characteristics, or neonatal outcome.     

FISH快速检测自然流产绒毛染色体非整倍体异常的临床价值

目的:探讨应用荧光原位杂交技术(FISH)对早期自然流产绒毛染色体非整倍体检测的临床价值。方法:对30例因自然流产行清宫术的绒毛组织行FISH分析,使用7种探针对13、16、18、21、22号和X、Y染色体进行了检测,并对这30例流产夫妇行外周血淋巴细胞染色体常规核型分析。结果:FISH分析的30例自然流产的绒毛组织中,有17例检测出了异常信号,检出率为57%,其中8例16-三体、2例22-三体、2例13-三体和5例三倍体。30例自然流产夫妇外周血淋巴细胞染色体核型未见异常。结论:FISH技术可以快速、简便地检测出流产物绒毛组织染色体非整倍体的异常,FISH技术的应用可以为自然流产夫妇遗传咨询提供重要的信息。